Painful legs and moving toes syndrome

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Qiu-ying Ma

2015-10-01

Full Text Available Painful legs and moving toes syndrome (PLMT is a rare movement disorder with low diagnostic rate, which is characterized by lower limb pain with involuntary movements of feet or toes. Etiology and pathogenesis of this disease is still unclear. Patients have different clinical manifestations, so the diagnosis is difficult. Treatment methods for PLMT are numerous, but so far the treatment of this disease is still a major challenge for clinicians. Further research is still needed to guide clinical work. DOI: 10.3969/j.issn.1672-6731.2015.10.013

The role of eccentric regime of leg muscle work in alpine skiing

Directory of Open Access Journals (Sweden)

Ropret Robert

2017-01-01

Full Text Available Alpine skiing is characterized by a great number of leg movements with muscle contractions in eccentric regime. The role of these movements is to absorb gravitation and inertial forces, manage skis more precisely and maintain balance. Recent studies have determined the volume, duration and intenisty of eccentric contractions as well as the basic characteristics of movement amplitudes and velocities. Based on the previous findings the experiments involving eccentric training using a bicycle ergometer confirmed a positive impact that this kind of training has on increasing maximum power, strength, endurance, coordination, injury prevention, metabolic work efficiency, more efficient work with longer muscle length and its role in miming skiers' movements. This paper is an review of the studies so far in the field of kinematics, skiing dynamics and the effect of eccentric training on the development of athletes' performances.

Estimation of peak heat flux onto the targets for CFETR with extended divertor leg

International Nuclear Information System (INIS)

Zhang, Chuanjia; Chen, Bin; Xing, Zhe; Wu, Haosheng; Mao, Shifeng; Luo, Zhengping; Peng, Xuebing; Ye, Minyou

2016-01-01

Highlights: • A hypothetical geometry is assumed to extend the outer divertor leg in CFETR. • Density scan SOLPS simulation is done to study the peak heat flux onto target. • Attached–detached regime transition in out divertor occurs at lower puffing rate. • Unexpected delay of attached–detached regime transition occurs in inner divertor. - Abstract: China Fusion Engineering Test Reactor (CFETR) is now in conceptual design phase. CFETR is proposed as a good complement to ITER for demonstrating of fusion energy. Divertor is a crucial component which faces the plasmas and handles huge heat power for CFETR and future fusion reactor. To explore an effective way for heat exhaust, various methods to reduce the heat flux to divertor target should be considered for CFETR. In this work, the effect of extended out divertor leg on the peak heat flux is studied. The magnetic configuration of the long leg divertor is obtained by EFIT and Tokamak Simulation Code (TSC), while a hypothetical geometry is assumed to extend the out divertor leg as long as possible inside vacuum vessel. A SOLPS simulation is performed to study peak heat flux of the long leg divertor for CFETR. D 2 gas puffing is used and increasing of the puffing rate means increase of plasma density. Both peak heat flux onto inner and outer targets are below 10 MW/m 2 is achieved. A comparison between the peak heat flux between long leg and conventional divertor shows that an attached–detached regime transition of out divertor occurs at lower gas puffing gas puffing rate for long leg divertor. While for the inner divertor, even the configuration is almost the same, the situation is opposite.

Estimation of peak heat flux onto the targets for CFETR with extended divertor leg

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chuanjia; Chen, Bin [School of Nuclear Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Xing, Zhe [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Wu, Haosheng [School of Nuclear Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Mao, Shifeng, E-mail: sfmao@ustc.edu.cn [School of Nuclear Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Luo, Zhengping; Peng, Xuebing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Ye, Minyou [School of Nuclear Science and Technology, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

2016-11-01

Highlights: • A hypothetical geometry is assumed to extend the outer divertor leg in CFETR. • Density scan SOLPS simulation is done to study the peak heat flux onto target. • Attached–detached regime transition in out divertor occurs at lower puffing rate. • Unexpected delay of attached–detached regime transition occurs in inner divertor. - Abstract: China Fusion Engineering Test Reactor (CFETR) is now in conceptual design phase. CFETR is proposed as a good complement to ITER for demonstrating of fusion energy. Divertor is a crucial component which faces the plasmas and handles huge heat power for CFETR and future fusion reactor. To explore an effective way for heat exhaust, various methods to reduce the heat flux to divertor target should be considered for CFETR. In this work, the effect of extended out divertor leg on the peak heat flux is studied. The magnetic configuration of the long leg divertor is obtained by EFIT and Tokamak Simulation Code (TSC), while a hypothetical geometry is assumed to extend the out divertor leg as long as possible inside vacuum vessel. A SOLPS simulation is performed to study peak heat flux of the long leg divertor for CFETR. D{sub 2} gas puffing is used and increasing of the puffing rate means increase of plasma density. Both peak heat flux onto inner and outer targets are below 10 MW/m{sup 2} is achieved. A comparison between the peak heat flux between long leg and conventional divertor shows that an attached–detached regime transition of out divertor occurs at lower gas puffing gas puffing rate for long leg divertor. While for the inner divertor, even the configuration is almost the same, the situation is opposite.

Approach to leg edema

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Fulvio Pomero

2017-09-01

Full Text Available Edema is defined as a palpable swelling caused by an increase in interstitial fluid volume. Leg edema is a common problem with a wide range of possible causes and is the result of an imbalance in the filtration system between the capillary and interstitial spaces. Major causes of edema include venous obstruction, increased capillary permeability and increased plasma volume secondary to sodium and water retention. In both hospital and general practice, the patient with a swollen leg presents a common dilemma in diagnosis and treatment. The cause may be trivial or life-threatening and it is often difficult to determine the clinical pathway. The diagnosis can be narrowed by categorizing the edema according to its duration, distribution (unilateral or bilateral and accompanying symptoms. This work provides clinically oriented recommendations for the management of leg edema in adults.

Evaluation of arm-leg coordination in flat breaststroke.

Science.gov (United States)

Chollet, D; Seifert, L; Leblanc, H; Boulesteix, L; Carter, M

2004-10-01

This study proposes a new method to evaluate arm-leg coordination in flat breaststroke. Five arm and leg stroke phases were defined with a velocity-video system. Five time gaps quantified the time between arm and leg actions during three paces of a race (200 m, 100 m and 50 m) in 16 top level swimmers. Based on these time gaps, effective glide, effective propulsion, effective leg insweep and effective recovery were used to identify the different stroke phases of the body. A faster pace corresponded to increased stroke rate, decreased stroke length, increased propulsive phases, shorter glide phases, and a shorter T1 time gap, which measured the effective body glide. The top level swimmers showed short time gaps (T2, T3, T4, measuring the timing of arm-leg recoveries), which reflected the continuity in arm and leg actions. The measurement of these time gaps thus provides a pertinent evaluation of swimmers' skill in adapting their arm-leg coordination to biomechanical constraints.

Determining of the Parking Manoeuvre and the Taxi Blockage Adjustment Factor for the Saturation Flow Rate at the Outlet Legs of Signalized Intersections: Case Study from Rasht City (Iran)

Science.gov (United States)

Behbahani, Hamid; Jahangir Samet, Mehdi; Najafi Moghaddam Gilani, Vahid; Amini, Amir

2017-10-01

The presence of taxi stops within the area of signalized intersections at the outlet legs due to unnatural behaviour of the taxis, sudden change of lanes, parking manoeuvres activities and stopping the vehicle to discharge or pick up the passengers have led to reduction of saturation flow rate at the outlet leg of signalized intersections and increased delay as well as affecting the performance of a crossing lane. So far, in term of evaluating effective adjustment factors on saturation flow rate at the inlet legs of the signalized intersections, various studies have been carried out, however; there has not been any studies on effective adjustment factors on saturation flow rate at the inlet legs. Hence, the evaluating of the traffic effects of unique behaviours on the saturation flow rate of the outlet leg is very important. In this research the parking manoeuvre time and taxi blockage time were evaluated and analyzed based on the available lane width as well as determining the effective adjustment factors on the saturation flow rate using recording related data at four signalized intersections in Rasht city. The results show that the average parking manoeuvre time is a function of the lane width and is increased as the lane width is reduced. Also, it is suggested to use the values of 7.37 and 11.31 seconds, respectively for the average parking manoeuvre time and the average blockage time of taxies at the outlet legs of signalized intersections for the traffic designing in Rasht city.

Possibility of leg muscle hypertrophy by ambulation in older adults: a brief review

Directory of Open Access Journals (Sweden)

Ozaki H

2013-03-01

Full Text Available Hayao Ozaki,1 Jeremy P Loenneke,2 Robert S Thiebaud,2 Joel M Stager,3 Takashi Abe31Juntendo University, Inzai, Chiba, Japan; 2Department of Health and Exercise Science, University of Oklahoma, Norman, OK, USA; 3Department of Kinesiology, Indiana University, Bloomington, IN, USAAbstract: It is known that ambulatory exercises such as brisk walking and jogging are potent stimuli for improving aerobic capacity, but it is less understood whether ambulatory exercise can increase leg muscle size and function. The purpose of this brief review is to discuss whether or not ambulatory exercise elicits leg muscle hypertrophy in older adults. Daily ambulatory activity with moderate (>3 metabolic equivalents [METs], which is defined as the ratio of the work metabolic rate to the resting metabolic rate intensity estimated by accelerometer is positively correlated with lower body muscle size and function in older adults. Although there is conflicting data on the effects of short-term training, it is possible that relatively long periods of walking, jogging, or intermittent running for over half a year can increase leg muscle size among older adults. In addition, slow-walk training with a combination of leg muscle blood flow restriction elicits muscle hypertrophy only in the blood flow restricted leg muscles. Competitive marathon running and regular high intensity distance running in young and middle-aged adults may not produce leg muscle hypertrophy due to insufficient recovery from the damaging running bout, although there have been no studies that have investigated the effects of running on leg muscle morphology in older subjects. It is clear that skeletal muscle hypertrophy can occur independently of exercise mode and load.Keywords: aerobic exercise, muscle mass, aging, strength, sarcopenia

An Under-the-Table Leg-Movement Apparatus and Changes in Energy Expenditure

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Gabriel A. Koepp

2017-05-01

Full Text Available Introduction: Deskwork contributes substantially to sedentariness. Here, we evaluated an under-the-table apparatus that was designed to promote leg movement (fidgeting while seated. Our hypothesis was that the under-the-table apparatus would increase energy expenditure.Methods: We measured energy expenditure and heart rate in 26 people while they sat and worked using a standard chair, walked on a treadmill, and sat and worked using an under-the-desk apparatus that encouraged leg movement.Results: Energy expenditure increased significantly while using the under-the-table apparatus when compared to the standard office chair (standard chair, 81 ± 18 kcal/h; under-the-table apparatus, 96 ± 23 kcal/h (P < 0.001; representing an 18 ± 16% increase. The changes in energy expenditure were not as great as walking (1 mph, 168 ± 46 kcal/h, P < 0.001; 2 mph, 205 ± 51 kcal/, P < 0.001, representing 107 ± 37% and 155 ± 48% increases over baseline, respectively.Conclusions: An under-the-table apparatus that promotes leg movement can increase energy expenditure by approximately 20%. Dynamic sitting is promoted by this apparatus and may be among a lexicon of options to help people move more while seated at work.

Quality-controlled dose reduction of full-leg radiography in patients with knee malalignment

Energy Technology Data Exchange (ETDEWEB)

Kloth, Jost Karsten; Neumann, Regina; Stiller, Wolfram; Kauczor, Hans-Ulrich; Weber, Marc-Andre [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Stillfried, Eva von; Ewerbeck, Volker [University Hospital Heidelberg, Department of Orthopedic and Trauma Surgery, Heidelberg (Germany)

2014-12-05

Digital plain radiographs of the full leg are frequently performed examinations of children and young adults. Thus, the objective of this work was to reduce the radiation exposure dependent on specific indications, and to determine objective quality-control criteria to ensure accurate assessment. Institutional review board approval and informed consent of all participants were obtained. In this prospective, randomized controlled, blinded, two-armed single-center study, 288 evaluable patients underwent plain radiography of the full leg with standard and reduced doses. The evaluation of the plain radiographs was conducted using the following criteria: mechanical axis, leg length, and maturation of the epiphyseal plate. Two blinded radiologists evaluated these criteria using a score ranging from 1 (definitely assessable) to 4 (not assessable). If a single criterion had been evaluated with a score of 3 or more points or all criteria with 2 points, the radiograph was scored as ''not assessable''. The study was designed as a non-inferiority trial. Eleven (3.8 %) examined X-rays were scored as not assessable. The rate of non-assessable radiographs with 33 % reduced dose was significantly not inferior to the rate of non-assessable radiographs with standard dose. The evaluation of the quality criteria was dose independent. Full-leg plain radiography in patients with knee malalignment can be performed at 33 % reduced dose without loss of relevant diagnostic information. (orig.)

Success rate of split-thickness skin grafting of chronic venous leg ulcers depends on the presence of Pseudomonas aeruginosa: a retrospective study

DEFF Research Database (Denmark)

Høgsberg, Trine; Bjarnsholt, Thomas; Thomsen, Jens Schiersing

2011-01-01

that once chronic venous leg ulcers were colonized (weeks or months preoperatively) by P. aeruginosa, the success rate of skin grafting deteriorated despite aggressive treatment. To investigate this, a retrospective study was performed on the clinical outcome of 82 consecutive patients with chronic venous...... regression analysis was carried out leaving P. aeruginosa as the only predictor left in the model (p¿=¿0.001). This study supports our hypothesis that P. aeruginosa in chronic venous leg ulcers, despite treatment, has considerable impact on partial take or rejection of split-thickness skin grafts....

Dynamic legged locomotion in robots and animals

Science.gov (United States)

Raibert, Marc; Playter, Robert; Ringrose, Robert; Bailey, Dave; Leeser, Karl

1995-01-01

This report documents our study of active legged systems that balance actively and move dynamically. The purpose of this research is to build a foundation of knowledge that can lead both to the construction of useful legged vehicles and to a better understanding of how animal locomotion works. In this report we provide an update on progress during the past year. Here are the topics covered in this report: (1) Is cockroach locomotion dynamic? To address this question we created three models of cockroaches, each abstracted at a different level. We provided each model with a control system and computer simulation. One set of results suggests that 'Groucho Running,' a type of dynamic walking, seems feasible at cockroach scale. (2) How do bipeds shift weight between the legs? We built a simple planar biped robot specifically to explore this question. It shifts its weight from one curved foot to the other, using a toe-off and toe-on strategy, in conjunction with dynamic tipping. (3) 3D biped gymnastics: The 3D biped robot has done front somersaults in the laboratory. The robot changes its leg length in flight to control rotation rate. This in turn provides a mechanism for controlling the landing attitude of the robot once airborne. (4) Passively stabilized layout somersault: We have found that the passive structure of a gymnast, the configuration of masses and compliances, can stabilize inherently unstable maneuvers. This means that body biomechanics could play a larger role in controlling behavior than is generally thought. We used a physical 'doll' model and computer simulation to illustrate the point. (5) Twisting: Some gymnastic maneuvers require twisting. We are studying how to couple the biomechanics of the system to its control to produce efficient, stable twisting maneuvers.

THE EFFECTS OF SINGLE LEG HOP PROGRESSION AND DOUBLE LEGS HOP PROGRESSION EXERCISE TO INCREASE SPEED AND EXPLOSIVE POWER OF LEG MUSCLE

Directory of Open Access Journals (Sweden)

Nining W. Kusnanik

2015-05-01

Full Text Available The main purpose of this study was to determine the effect of single leg hop progression and double legs hop progression exercise to increase speed and explosive power of leg muscles. Plyometric is one of the training methods that can increase explosive power. There are many models of plyometric training including single leg hop progression and double leg hop progression. This research was experimental using match subject design techniques. The subjects of this study were 39 students who joined basketball school club. There were 3 groups in this study: Group 1 were 13 students who given sin¬gle leg hop progression exercise, Group 2 were 13 students who given double legs hop progression exercise, Group 3 were 13 students who given conventional exercise. The data was collected during pre test and post test by testing 30m speed running and vertical jump. The data was analyzed using Analysis of Varians (Anova. It was found that there were significantly increased on speed and explosive power of leg muscles of Group 1 and Group 2. It can be stated that single leg hop progression exercise was more effective than double leg hop progression exercise. The recent findings supported the hypothesis that single leg hop progression and double legs hop progression exercise can increase speed and explosive power of leg muscles. These finding were supported by some previous studies (Singh, et al, 2011; Shallaby, H.K., 2010. The single leg hop progression is more effective than double legs hop progression. This finding was consistent with some previous evidences (McCurdy, et al, 2005; Makaruk et al, 2011.

Leg symptoms associated with sacroiliac joint disorder and related pain.

Science.gov (United States)

Murakami, Eiichi; Aizawa, Toshimi; Kurosawa, Daisuke; Noguchi, Kyoko

2017-06-01

The symptoms of sacroiliac joint (SIJ) disorders are usually detected in the buttock and groin, and occasionally referred to the thigh and leg. However, lumbar disorders also cause symptoms in these same body regions. The presence of a characteristic, symptomatic pattern in the legs would be useful for diagnosing SIJ disorders. This study aimed to identify specific leg symptoms in patients with SIJ pain originating from the posterior sacroiliac ligament and determine the rate of occurrence of these symptoms. The source population consisted of 365 consecutive patients from February 2005 to December 2007. One hundred patients were diagnosed with SIJ pain by a periarticular SIJ injection (42 males and 58 females, average age 46 years, age range, 18-75 years). A leg symptom map was made by subtracting the symptoms after a periarticular SIJ injection from the initial symptoms, and evaluating the rate of each individual symptom by area. Ninety-four patients reported pain at or around the posterior-superior iliac spine (PSIS). Leg symptoms comprised pain and a numbness/tingling sensation; ≥60% of the patients had these symptoms. Pain was mainly detected in the back, buttock, groin, and thigh areas, while numbness/tingling was mainly detected in the lateral to posterior thigh and back of the calf. Leg symptoms associated with SIJ pain originating from the posterior sacroiliac ligament include both pain and numbness, which do not usually correspond to the dermatome. These leg symptoms in addition to pain around the PSIS may indicate SIJ disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

A survey of bio-inspired compliant legged robot designs

International Nuclear Information System (INIS)

Zhou Xiaodong; Bi Shusheng

2012-01-01

The roles of biological springs in vertebrate animals and their implementations in compliant legged robots offer significant advantages over the rigid legged ones in certain types of scenarios. A large number of robotics institutes have been attempting to work in conjunction with biologists and incorporated these principles into the design of biologically inspired robots. The motivation of this review is to investigate the most published compliant legged robots and categorize them according to the types of compliant elements adopted in their mechanical structures. Based on the typical robots investigated, the trade-off between each category is summarized. In addition, the most significant performances of these robots are compared quantitatively, and multiple available solutions for the future compliant legged robot design are suggested. Finally, the design challenges for compliant legged robots are analysed. This review will provide useful guidance for robotic designers in creating new designs by inheriting the virtues of those successful robots according to the specific tasks. (topical review)

The Relationship among Leg Strength, Leg Power and Alpine Skiing Success.

Science.gov (United States)

Gettman, Larry R.; Huckel, Jack R.

The purpose of this study was to relate leg strength and power to alpine skiing success as measured by FIS points. Isometric leg strength was represented by the knee extension test described by Clarke. Leg power was measured by the vertical jump test and the Margaria-Kalamen stair run. Results in the strength and power tests were correlated with…

A tracked robot with novel bio-inspired passive "legs".

Science.gov (United States)

Sun, Bo; Jing, Xingjian

2017-01-01

For track-based robots, an important aspect is the suppression design, which determines the trafficability and comfort of the whole system. The trafficability limits the robot's working capability, and the riding comfort limits the robot's working effectiveness, especially with some sensitive instruments mounted on or operated. To these aims, a track-based robot equipped with a novel passive bio-inspired suspension is designed and studied systematically in this paper. Animal or insects have very special leg or limb structures which are good for motion control and adaptable to different environments. Inspired by this, a new track-based robot is designed with novel "legs" for connecting the loading wheels to the robot body. Each leg is designed with passive structures and can achieve very high loading capacity but low dynamic stiffness such that the robot can move on rough ground similar to a multi-leg animal or insect. Therefore, the trafficability and riding comfort can be significantly improved without losing loading capacity. The new track-based robot can be well applied to various engineering tasks for providing a stable moving platform of high mobility, better trafficability and excellent loading capacity.

The one-leg standing radiograph

OpenAIRE

Pinsornsak, P.; Naratrikun, K.; Kanitnate, S.; Sangkomkamhang, T.

2016-01-01

Objectives The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis wa...

Evaluation of Thermoelectric Performance and Durability of Functionalized Skutterudite Legs

Science.gov (United States)

Skomedal, Gunstein; Kristiansen, Nils R.; Sottong, Reinhard; Middleton, Hugh

2017-04-01

Thermoelectric generators are a promising technology for waste heat recovery. As new materials and devices enter a market penetration stage, it is of interest to employ fast and efficient measurement methods to evaluate the long-term stability of thermoelectric materials in combination with metallization and coating (functionalized thermoelectric legs). We have investigated a method for measuring several thermoelectric legs simultaneously. The legs are put under a common temperature gradient, and the electrical characteristics of each leg are measured individually during thermal cycling. Using this method, one can test different types of metallization and coating applied to skutterudite thermoelectric legs and look at the relative changes over time. Postcharacterization of these initial tests with skutterudite legs using a potential Seebeck microprobe and an electron microscope showed that oxidation and interlayer diffusion are the main reasons for the gradual increase in internal resistance and the decrease in open-circuit voltage. Although we only tested skutterudite material in this work, the method is fully capable of testing all kinds of material, metallization, and coating. It is thus a promising method for studying the relationship between failure modes and mechanisms of functionalized thermoelectric legs.

Leg Regrowth in Blaberus discoidalis (Discoid Cockroach following Limb Autotomy versus Limb Severance and Relevance to Neurophysiology Experiments.

Directory of Open Access Journals (Sweden)

Timothy C Marzullo

Full Text Available Many insects can regenerate limbs, but less is known about the regrowth process with regard to limb injury type. As part of our neurophysiology education experiments involving the removal of a cockroach leg, 1 the ability of Blaberus discoidalis cockroaches to regenerate a metathoracic leg was examined following autotomy at the femur/trochanter joint versus severance via a transverse coxa-cut, and 2 the neurophysiology of the detached legs with regard to leg removal type was studied by measuring spike firing rate and microstimulation movement thresholds.First appearance of leg regrowth was after 5 weeks in the autotomy group and 12 weeks in the coxa-cut group. Moreover, regenerated legs in the autotomy group were 72% of full size on first appearance, significantly larger (p<0.05 than coxa-cut legs (29% of full size at first appearance. Regenerated legs in both groups grew in size with each subsequent molt; the autotomy-removed legs grew to full size within 18 weeks, whereas coxa-cut legs took longer than 28 weeks to regrow. Removal of the metathoracic leg in both conditions did not have an effect on mortality compared to matched controls with unmolested legs.Autotomy-removed legs had lower spontaneous firing rates, similar marked increased firing rates upon tactile manipulation of tibial barbs, and a 10% higher electrical microstimulation threshold for movement.It is recommended that neurophysiology experiments on cockroach legs remove the limb at autotomy joints instead of coxa cuts, as the leg regenerates significantly faster when autotomized and does not detract from the neurophysiology educational content.

Foot, leg, and ankle swelling

Science.gov (United States)

Swelling of the ankles - feet - legs; Ankle swelling; Foot swelling; Leg swelling; Edema - peripheral; Peripheral edema ... Foot, leg, and ankle swelling is common when the person also: Is overweight Has a blood clot in the leg Is older Has ...

Computational simulation of passive leg-raising effects on hemodynamics during cardiopulmonary resuscitation.

Science.gov (United States)

Shin, Dong Ah; Park, Jiheum; Lee, Jung Chan; Shin, Sang Do; Kim, Hee Chan

2017-03-01

The passive leg-raising (PLR) maneuver has been used for patients with circulatory failure to improve hemodynamic responsiveness by increasing cardiac output, which should also be beneficial and may exert synergetic effects during cardiopulmonary resuscitation (CPR). However, the impact of the PLR maneuver on CPR remains unclear due to difficulties in monitoring cardiac output in real-time during CPR and a lack of clinical evidence. We developed a computational model that couples hemodynamic behavior during standard CPR and the PLR maneuver, and simulated the model by applying different angles of leg raising from 0° to 90° and compression rates from 80/min to 160/min. The simulation results showed that the PLR maneuver during CPR significantly improves cardiac output (CO), systemic perfusion pressure (SPP) and coronary perfusion pressure (CPP) by ∼40-65% particularly under the recommended range of compression rates between 100/min and 120/min with 45° of leg raise, compared to standard CPR. However, such effects start to wane with further leg lifts, indicating the existence of an optimal angle of leg raise for each person to achieve the best hemodynamic responses. We developed a CPR-PLR model and demonstrated the effects of PLR on hemodynamics by investigating changes in CO, SPP, and CPP under different compression rates and angles of leg raising. Our computational model will facilitate study of PLR effects during CPR and the development of an advanced model combined with circulatory disorders, which will be a valuable asset for further studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Immediate Effects of Smoking on Cardiorespiratory Responses During Dynamic Exercise: Arm Versus Leg Ergometry

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Chien-Liang eChen

2015-12-01

Full Text Available Purpose: This study compared the immediate effects of smoking on cardiorespiratory responses to dynamic arm and leg exercises. Methods: This randomized crossover study recruited 14 college students. Each participant underwent 2 sets of arm-cranking (AC and leg-cycling (LC exercise tests. The testing sequences of the control trial (participants refrained from smoking for 8 hours before testing and the experimental trial (participants smoked 2 cigarettes were randomly chosen. We observed immediate changes in pulmonary function and heart rate variability after smoking and before the exercise test. The participants then underwent graded exercise tests of their arms and legs, respectively, until reaching exhaustion. We compared the peak work achieved and the time to exhaustion during the exercise tests with various cardiorespiratory indices [i.e., heart rate, oxygen consumption (VO2, minute ventilation (VE]. The main effects of the time and the trial, as well as their interaction effects on outcome measures, were investigated using repeated measure ANOVA.Results: Five minutes after smoking, the participants exhibited reduced forced vital capacities and forced expiratory volumes in the first second (P < .05, in addition to elevated resting heart rates (P < .001. The high-frequency, low-frequency, and the total power of the heart rate variability were also reduced (P < .05 at rest. For the exercise test periods, smoking reduced the time to exhaustion (P = .005 and the ventilatory threshold (P < .05 in the LC tests, whereas there were no significant effects in the AC tests. A trend analysis revealed a significant (P < .001 trial-by-time interaction effect for heart rate, VO2, and VE during the graded exercise test. Lower VO2 and VE levels were exhibited in the exercise response of the smoking trial than in that of the control LC trials, whereas there was no discernable inter-trial difference in the AC trials. Moreover, the differences in heart rate

Immediate Effects of Smoking on Cardiorespiratory Responses During Dynamic Exercise: Arm Vs. Leg Ergometry.

Science.gov (United States)

Chen, Chien-Liang; Tang, Jing-Shia; Li, Ping-Chia; Chou, Pi-Ling

2015-01-01

This study compared the immediate effects of smoking on cardiorespiratory responses to dynamic arm and leg exercises. This randomized crossover study recruited 14 college students. Each participant underwent two sets of arm-cranking (AC) and leg-cycling (LC) exercise tests. The testing sequences of the control trial (participants refrained from smoking for 8 h before testing) and the experimental trial (participants smoked two cigarettes immediately before testing) were randomly chosen. We observed immediate changes in pulmonary function and heart rate variability after smoking and before the exercise test. The participants then underwent graded exercise tests of their arms and legs until reaching exhaustion. We compared the peak work achieved and time to exhaustion during the exercise tests with various cardiorespiratory indices [i.e., heart rate, oxygen consumption (VO2), minute ventilation (VE)]. The differences between the smoking and control trials were calculated using paired t-tests. For the exercise test periods, VO2, heart rate, and VE values were calculated at every 10% increment of the maximal effort time. The main effects of the time and trial, as well as their trial-by-time (4 × 10) interaction effects on the outcome measures, were investigated using repeated measure ANOVA with trend analysis. 5 min after smoking, the participants exhibited reduced forced vital capacities and forced expiratory volumes in the first second (P exercise test periods, smoking reduced the time to exhaustion (P = 0.005) and the ventilatory threshold (P exercise test (all P exercise response of the smoking trial than in those of the control LC trials, whereas no discernable inter-trial difference was observed in the AC trials. Moreover, the differences in heart rate and VE response between the LC and AC exercises were significantly smaller after the participants smoked. This study verified that smoking significantly decreased performance and cardiorespiratory responses to leg

Maximal loads acting on legs of powered roof support unit in longwalls with bumping hazards

Institute of Scientific and Technical Information of China (English)

StanislawSzweda

2001-01-01

In the article the results of measurements of the resultant force in the legs of a powered roof support unit, caused by a dynamic interaction bf the rock mass, are discussed. The measurements have been taken in the Iongwalls mined with a roof fall, characterized by the highest degree of bumping hazard. It has been stated that the maximal force in the legs Fro, recorded during a dynamic interaction of the rock mass, is proportional to the initial static force in the legs Fst.p Therefore a need for a careful selection of the initial load of the powered roof support, according to the local mining and geological conditions, results from such a statement. Setting the legs with the supporting load exceeding the indispensable value for keeping the direct roof solids in balance, deteriorating the operational parameters of a Iongwall system also has a disadvantageous influence on the value of the force in the legs and the rate of its increase, caused by a dynamic interaction of the rock mass. A correct selection of the initial load causes a decrease in the intensity of a dynamic interaction of the rock mass on powered roof supports, which also has an advanta igeous influence on their life, Simultaneously with the measurements of the resultant force in the legs, the vertical acceleration of the canopy was also recorded. It has enabled to prove that the external dynamic forces may act on the unit both from the roof as well as from the floor. The changes of the force in the legs caused by dynamic phenomena intrinsically created in the roof and changes of the force in the legs caused by blasting explosives in the roof of the working, have been analyzed separately. It has been stated that an increase in the loads of legs, caused by intrinsic phenomena is significantly higher than a force increase in the legs caused by blasting. It means that powered roof supports, to be operated in the workings, where the bumping hazard occurs, will also transmit the loads acting on a unit

Genetic parameters for claw and leg health, foot and leg conformation, and locomotion in Danish Holsteins

DEFF Research Database (Denmark)

Laursen, M. V.; Boelling, D.; Mark, Thomas

2009-01-01

was defined as absence of hock infection, swollen hock, and bruising. The potential indicators were locomotion and foot and leg conformation, represented by rear leg side view, rear leg rear view, foot angle, and apparent hock quality and bone structure. The study was conducted using records from 429......,877 Danish Holstein cows in first lactation. Binary health traits were divided into 3 subcategories: claw health, leg health, and absence of all claw and leg disorders. Genetic (r(g)) and phenotypic correlations were estimated using a bivariate linear sire model and REML. Estimated heritabilities were 0.......01 for all 3 combined claw and leg health traits (on the observed binary scale), 0.09 for locomotion, 0.14 for rear leg rear view, 0.19 for rear leg side view, 0.13 for foot angle, 0.22 for apparent hock quality, and 0.27 for apparent bone structure. Heritabilities were 0.06 and 0.01 for claw health and leg...

Effects of combined and classic training on different isometric rate of force development parameters of leg extensors in female volleyball players: Discriminative analysis approach

Directory of Open Access Journals (Sweden)

Rajić Branislav

2013-01-01

Full Text Available Background: The aim of this study is to verify the effects of the combined and classic training of different isometric rates of force development (RFD parameters of legs. Materials and Methods: Three groups of female athletes was tested: Experimental group (N = 12, classically trained group (N = 11, and control group (N = 20 of athletes. The isometric "standing leg extension" and "Rise on Toes" tests were conducted to evaluate the maximal force, time necessary time to reach it and the RFD analyzed at 100 ms, 180 ms, 250 ms from the onset, and 50-100% of its maximal result. Results: The maximal RFD of legs and calves are dominant explosive parameters. Special training enhanced the RFD of calves of GROUP SPEC at 100 ms (P = 0.05, at 180 ms (P = 0.039, at 250 ms (P = 0.039, at 50% of the F max (P = 0.031 and the F max (P = 0.05. Domination of GROUP SPEC toward GROUP CLASS and GROUP CONTROL is in case of legs at 100 ms (P = 0.04; at 180 ms (P = 0.04; at 250 ms (P = 0.00; at 50% of the F max (P = 0.01 and at the F max (P = 0.00; in case of calves at 100 ms (P = 0.07; 180 ms (P = 0.001; at 250 ms (P = 0.00; at 50% of the F max (P = 0.00 and at F max (P = 0.000. Conclusion: Dominant explosive factors are maximal RFD of leg extensors and calves, and legs at 250ms. Specific training enhanced explosiveness of calves of GROUP SPEC general and partial domination of GROUP SPEC by 87% over GROUP CLASS , and 35% over GROUP CONTROL .

Volume measurement of the leg with the depth camera for quantitative evaluation of edema

Science.gov (United States)

Kiyomitsu, Kaoru; Kakinuma, Akihiro; Takahashi, Hiroshi; Kamijo, Naohiro; Ogawa, Keiko; Tsumura, Norimichi

2017-02-01

Volume measurement of the leg is important in the evaluation of leg edema. Recently, method for measurement by using a depth camera is proposed. However, many depth cameras are expensive. Therefore, we propose a method using Microsoft Kinect. We obtain a point cloud of the leg by Kinect Fusion technique and calculate the volume. We measured the volume of leg for three healthy students during three days. In each measurement, the increase of volume was confirmed from morning to evening. It is known that the volume of leg is increased in doing office work. Our experimental results meet this expectation.

Stable walking with asymmetric legs

International Nuclear Information System (INIS)

Merker, Andreas; Rummel, Juergen; Seyfarth, Andre

2011-01-01

Asymmetric leg function is often an undesired side-effect in artificial legged systems and may reflect functional deficits or variations in the mechanical construction. It can also be found in legged locomotion in humans and animals such as after an accident or in specific gait patterns. So far, it is not clear to what extent differences in the leg function of contralateral limbs can be tolerated during walking or running. Here, we address this issue using a bipedal spring-mass model for simulating walking with compliant legs. With the help of the model, we show that considerable differences between contralateral legs can be tolerated and may even provide advantages to the robustness of the system dynamics. A better understanding of the mechanisms and potential benefits of asymmetric leg operation may help to guide the development of artificial limbs or the design novel therapeutic concepts and rehabilitation strategies.

Delivery of compression therapy for venous leg ulcers.

Science.gov (United States)

Zarchi, Kian; Jemec, Gregor B E

2014-07-01

Despite the documented effect of compression therapy in clinical studies and its widespread prescription, treatment of venous leg ulcers is often prolonged and recurrence rates high. Data on provided compression therapy are limited. To assess whether home care nurses achieve adequate subbandage pressure when treating patients with venous leg ulcers and the factors that predict the ability to achieve optimal pressure. We performed a cross-sectional study from March 1, 2011, through March 31, 2012, in home care centers in 2 Danish municipalities. Sixty-eight home care nurses who managed wounds in their everyday practice were included. Participant-masked measurements of subbandage pressure achieved with an elastic, long-stretch, single-component bandage; an inelastic, short-stretch, single-component bandage; and a multilayer, 2-component bandage, as well as, association between achievement of optimal pressure and years in the profession, attendance at wound care educational programs, previous work experience, and confidence in bandaging ability. A substantial variation in the exerted pressure was found: subbandage pressures ranged from 11 mm Hg exerted by an inelastic bandage to 80 mm Hg exerted by a 2-component bandage. The optimal subbandage pressure range, defined as 30 to 50 mm Hg, was achieved by 39 of 62 nurses (63%) applying the 2-component bandage, 28 of 68 nurses (41%) applying the elastic bandage, and 27 of 68 nurses (40%) applying the inelastic bandage. More than half the nurses applying the inelastic (38 [56%]) and elastic (36 [53%]) bandages obtained pressures less than 30 mm Hg. At best, only 17 of 62 nurses (27%) using the 2-component bandage achieved subbandage pressure within the range they aimed for. In this study, none of the investigated factors was associated with the ability to apply a bandage with optimal pressure. This study demonstrates the difficulty of achieving the desired subbandage pressure and indicates that a substantial proportion of

Venous leg ulcers

Science.gov (United States)

2008-01-01

Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 80 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide, thromboxane alpha2 antagonists, zinc), peri

The cost of leg forces in bipedal locomotion: a simple optimization study.

Directory of Open Access Journals (Sweden)

John R Rebula

Full Text Available Simple optimization models show that bipedal locomotion may largely be governed by the mechanical work performed by the legs, minimization of which can automatically discover walking and running gaits. Work minimization can reproduce broad aspects of human ground reaction forces, such as a double-peaked profile for walking and a single peak for running, but the predicted peaks are unrealistically high and impulsive compared to the much smoother forces produced by humans. The smoothness might be explained better by a cost for the force rather than work produced by the legs, but it is unclear what features of force might be most relevant. We therefore tested a generalized force cost that can penalize force amplitude or its n-th time derivative, raised to the p-th power (or p-norm, across a variety of combinations for n and p. A simple model shows that this generalized force cost only produces smoother, human-like forces if it penalizes the rate rather than amplitude of force production, and only in combination with a work cost. Such a combined objective reproduces the characteristic profiles of human walking (R² = 0.96 and running (R² = 0.92, more so than minimization of either work or force amplitude alone (R² = -0.79 and R² = 0.22, respectively, for walking. Humans might find it preferable to avoid rapid force production, which may be mechanically and physiologically costly.

Influence of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing.

Science.gov (United States)

Karimi, Zanyar; Allahyari, Teimour; Azghani, Mahmood Reza; Khalkhali, Hamidreza

2016-03-01

The present study was an attempt to investigate the effect of unstable footwear on lower leg muscle activity, volume change and subjective discomfort during prolonged standing. Ten healthy subjects were recruited to stand for 2 h in three footwear conditions: barefoot, flat-bottomed shoe and unstable shoe. During standing, lower leg discomfort and EMG activity of medial gastrocnemius (MG) and tibialis anterior (TA) muscles were continuously monitored. Changes in lower leg volume over standing time also were measured. Lower leg discomfort rating reduced significantly while subjects standing on unstable shoe compared to the flat-bottomed shoe and barefoot condition. For lower leg volume, less changes also were observed with unstable shoe. The activity level and variation of right MG muscle was greater with unstable shoe compared to the other footwear conditions; however regarding the left MG muscle, significant difference was found between unstable shoe and flat-bottomed shoe only for activity level. Furthermore no significant differences were observed for the activity level and variation of TA muscles (right/left) among all footwear conditions. The findings suggested that prolonged standing with unstable footwear produces changes in lower leg muscles activity and leads to less volume changes. Perceived discomfort also was lower for this type of footwear and this might mean that unstable footwear can be used as ergonomic solution for employees whose work requires prolonged standing. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A study on the temperature distribution in the hot leg pipe

International Nuclear Information System (INIS)

Choe, Yoon-Jae; Baik, Se-Jin; Jang, Ho-Cheol; Lee, Byung-Jin; Im, In-Young; Ro, Tae-Sun

2003-01-01

In the hot leg pipes of reactor coolant system of the Korean Standard Nuclear Power Plant (KSNP), a non-uniform distribution in temperature has been observed across the cross-section, which is attributed to the non-uniformity of power distribution in the reactor core usually having a peak in the center region, and to the colder coolant bypass flow through the reactor vessel outlet nozzle clearances. As a result, the arithmetic mean temperature of four Resistance Temperature Detectors (RTDs) installed in each hot leg - two in the upper region and two in the lower region around the pipe wall may not correctly represent the actual coolant bulk temperature. It is also believed that there is a skewness in the velocity profile in the hot leg pipe due to the sudden changes in the flow direction and area from the core to the hot leg pipe, through the reactor vessel outlet plenum. These temperature non-uniformity and velocity skewness affect the measurement of the plant parameter such as the reactor coolant flow rate which is calculated by using the bulk temperature of hot leg pipes. A computational analysis has been performed to simulate the temperature and velocity distributions and to evaluate the uncertainty of temperature correction offset in the hot leg pipe. A commercial CFD code, FLUENT, is used for this analysis. The analysis results are compared with the operational data of KSNP and the scaled-down model test data for System 80. From the comparisons, an uncertainty of correction offset is obtained to measure the bulk temperature of hot leg more accurately, which can be also applied to the operating plants, leading to the reduction of temperature measurement uncertainty. Since the uncertainty of temperature in the hot leg pipe is one of major parameters to calculate the uncertainty of the reactor coolant flow rate, the analysis results can contribute to the improvement of the plant performance and safety by reducing the uncertainty of temperature measurement

Lyden-af-Leg

DEFF Research Database (Denmark)

Toft, Herdis

Præsentation af seniorforsker-projekt Lyden-af-Leg i et traderingsperspektiv og med indledende fokus på YouTube som traderings-platform.......Præsentation af seniorforsker-projekt Lyden-af-Leg i et traderingsperspektiv og med indledende fokus på YouTube som traderings-platform....

Sleep disturbances in restless legs syndrome

Directory of Open Access Journals (Sweden)

Jović Jasmina

2018-01-01

Full Text Available Background/Aim. Resteless legs syndrome (RLS is chronical neurological disorder characterized by urge to move legs that is usually accompanied by unpleasant sensations in the lower extremities. Sleep disturbance is one of the main accompanying symptoms of RLS which exists in approximatelly 90% of patients. Impairment of sleep is related to daily sleepiness, depressive and anxiety disorders. The aim of this study was to detect frequency and characterisitics of sleep-related symptoms in patients with RLS, and its impairrment to daily sleepiness, fatique, anxiety and depression. Methods. We have examinated 94 patients with RLS. The diagnose of RLS was based on questionnaire with 4 specific questions according to the International Restless Legs Syndrome Study Group (IRLSSG criteria updated in 2003. Severity of symptoms was astimated with IRLSSG Rating Scale, depression and anxiety with Hamilton Depression Rating Scale (HDRS and Hamilton Anxiety Rating Scale (HARS and sleepiness with Epworth Sleepiness scale (ESS. We astimated sleep characteristics and disturbances with specific questionnaire. Results. In our study 79.9% of patients had sleep-related symptoms. Average sleep duration was 6.50 ± 1.42 hours, with average frequency of awakening 2.34 ± 1.69 times per night. Average ESS score was 5.12 ± 4.08 (0–17. Patients with more severe symptoms had higher degree of sleepiness (p = 0.005. Patients with higher symptoms frequency, significantly more often had sleep disturbance (p = 0.016, tiredness and daily sleepiness (p = 0.001. Daily sleepiness (ESS also significantly correlates with depression (p < 0.05 and anxiety (p = 0.012. Conclusion. Our results confirm that sleep disturbances are one of the key accompanying symptoms of RLS which cause daily sleepiness, tiredness, depression and anxiety. Therefore, their early recognition and appropriate treatment must be a priority in RLS patients.

Maximal loads acting on legs of powered roof support unit in longwalls with bumping hazards

Institute of Scientific and Technical Information of China (English)

Stanislaw Szweda

2001-01-01

In the article the results of measurements of the resultant force in th e legs of a powered roof support unit, caused by a dynamic interaction of the ro ck mass, are discussed. The measurements have been taken in the longwalls mined with a roof fall, characterized by the highest degree of bumping hazard. It has been stated that the maximal force in the legs Fm, recorded during a dynam ic interaction of the rock mass, is proportional to the initial static force in the legs Fst,p. Th erefore a need for a careful selection of the initial load of the powered roof s upport, according to the local mining and geological conditions, results from su ch a statement. Setting the legs with the supporting load exceeding the indispen sable value for keeping the direct roof solids in balance, deteriorating the ope rational parameters of a longwall system also has a disadvantageous influence on the value of the force in the legs and the rate of its increase, caused by a dy namic interaction of the rock mass. A correct selection of the initial load caus es a decrease in the intensity of a dynamic interaction of the rock mass on powe red roof supports, which also has an advantageous influence on their life. 　　Simultaneously with the measurements of the resultant force in the legs, the vertical acceleration of the canopy was also recorded. It has enabled to prove that the exte rnal dynamic forces may act on the unit both from the roof as well as from the f loor. The changes of the force in the legs caused by dynamic phenomena intrinsic ally created in the roof and changes of the force in the legs caused by blasting explosives in the roof of the working, have been analyzed separately. It has been stated that an increase in the loads of legs, caused by intrinsi c phenomena is significantly higher than a force increase in the legs caused by blasting. It means that powered roof supports, to be operated in the workings, w here the bumping hazard occurs, will also transmit the loads

Increasing trunk flexion transforms human leg function into that of birds despite different leg morphology.

Science.gov (United States)

Aminiaghdam, Soran; Rode, Christian; Müller, Roy; Blickhan, Reinhard

2017-02-01

Pronograde trunk orientation in small birds causes prominent intra-limb asymmetries in the leg function. As yet, it is not clear whether these asymmetries induced by the trunk reflect general constraints on the leg function regardless of the specific leg architecture or size of the species. To address this, we instructed 12 human volunteers to walk at a self-selected velocity with four postures: regular erect, or with 30 deg, 50 deg and maximal trunk flexion. In addition, we simulated the axial leg force (along the line connecting hip and centre of pressure) using two simple models: spring and damper in series, and parallel spring and damper. As trunk flexion increases, lower limb joints become more flexed during stance. Similar to birds, the associated posterior shift of the hip relative to the centre of mass leads to a shorter leg at toe-off than at touchdown, and to a flatter angle of attack and a steeper leg angle at toe-off. Furthermore, walking with maximal trunk flexion induces right-skewed vertical and horizontal ground reaction force profiles comparable to those in birds. Interestingly, the spring and damper in series model provides a superior prediction of the axial leg force across trunk-flexed gaits compared with the parallel spring and damper model; in regular erect gait, the damper does not substantially improve the reproduction of the human axial leg force. In conclusion, mimicking the pronograde locomotion of birds by bending the trunk forward in humans causes a leg function similar to that of birds despite the different morphology of the segmented legs. © 2017. Published by The Company of Biologists Ltd.

Two Legged Walking Robot

OpenAIRE

Kraus, V.

2015-01-01

The aim of this work is to construct a two-legged wirelessly controlled walking robot. This paper describes the construction of the robot, its control electronics, and the solution of the wireless control. The article also includes a description of the application to control the robot. The control electronics of the walking robot are built using the development kit Arduino Mega, which is enhanced with WiFi module allowing the wireless control, a set of ultrasonic sensors for detecting obstacl...

PWR hot leg natural circulation modeling with MELCOR code

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

1998-12-31

Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

PWR hot leg natural circulation modeling with MELCOR code

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

1997-12-31

Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

Change of International Restless Legs Syndrome Study Group Rating Scale subscales with treatment and placebo: a pilot study

Directory of Open Access Journals (Sweden)

Mitchell UH

2014-02-01

Full Text Available Ulrike H Mitchell,1 Sterling C Hilton2 1Brigham Young University, Department of Exercise Sciences, 2Department of Educational Leadership and Foundations, Provo, UT, USA Background: In 2003, the 10-question International Restless Legs Syndrome Study Group Rating Scale (IRLS was developed as a means of assessing the severity of restless legs syndrome. Two subscales were identified: symptom severity (SS 1 and symptom impact (SS 2. Only one study has investigated the subscales' responsiveness to a 12-week treatment with ropinirole. This current study was undertaken to assess the impact of a 4-week, non-pharmaceutical treatment on the two subscales and to explore whether or not both subscales were impacted by the observed placebo effect. Methods: The pooled data from questionnaires of 58 patients (41 from both treatment groups and 17 from the sham treatment control group, who participated in two clinical studies, were reviewed. Their change in score over a 4-week trial was computed. The average change in both subscales in both groups was computed and t-tests were performed. Results: In the treatment group, the average scores of both subscales changed significantly from baseline to week 4 (P<0.005 for both. Compared to the control, SS 1 changed (P<0.001, but not SS 2 (P=0.18. In the sham treatment group, the scores for SS 1 changed significantly (P=0.002, but not for SS 2 (P=0.2. Conclusion: This study corroborated findings from an earlier study in which both subscales changed with a 12-week drug treatment. It also showed that the observed placebo effect is attributed to a small but significant change in symptom severity, but not symptom impact. Keywords: restless legs syndrome, RLS severity scale, IRLS subscales, symptom impact, symptom severity

Bio-inspired swing leg control for spring-mass robots running on ground with unexpected height disturbance

International Nuclear Information System (INIS)

Vejdani, H R; Hurst, J W; Blum, Y; Daley, M A

2013-01-01

We proposed three swing leg control policies for spring-mass running robots, inspired by experimental data from our recent collaborative work on ground running birds. Previous investigations suggest that animals may prioritize injury avoidance and/or efficiency as their objective function during running rather than maintaining limit-cycle stability. Therefore, in this study we targeted structural capacity (maximum leg force to avoid damage) and efficiency as the main goals for our control policies, since these objective functions are crucial to reduce motor size and structure weight. Each proposed policy controls the leg angle as a function of time during flight phase such that its objective function during the subsequent stance phase is regulated. The three objective functions that are regulated in the control policies are (i) the leg peak force, (ii) the axial impulse, and (iii) the leg actuator work. It should be noted that each control policy regulates one single objective function. Surprisingly, all three swing leg control policies result in nearly identical subsequent stance phase dynamics. This implies that the implementation of any of the proposed control policies would satisfy both goals (damage avoidance and efficiency) at once. Furthermore, all three control policies require a surprisingly simple leg angle adjustment: leg retraction with constant angular acceleration. (paper)

Bio-inspired swing leg control for spring-mass robots running on ground with unexpected height disturbance.

Science.gov (United States)

Vejdani, H R; Blum, Y; Daley, M A; Hurst, J W

2013-12-01

We proposed three swing leg control policies for spring-mass running robots, inspired by experimental data from our recent collaborative work on ground running birds. Previous investigations suggest that animals may prioritize injury avoidance and/or efficiency as their objective function during running rather than maintaining limit-cycle stability. Therefore, in this study we targeted structural capacity (maximum leg force to avoid damage) and efficiency as the main goals for our control policies, since these objective functions are crucial to reduce motor size and structure weight. Each proposed policy controls the leg angle as a function of time during flight phase such that its objective function during the subsequent stance phase is regulated. The three objective functions that are regulated in the control policies are (i) the leg peak force, (ii) the axial impulse, and (iii) the leg actuator work. It should be noted that each control policy regulates one single objective function. Surprisingly, all three swing leg control policies result in nearly identical subsequent stance phase dynamics. This implies that the implementation of any of the proposed control policies would satisfy both goals (damage avoidance and efficiency) at once. Furthermore, all three control policies require a surprisingly simple leg angle adjustment: leg retraction with constant angular acceleration.

Leg Injuries and Disorders

Science.gov (United States)

... are important for motion and standing. Playing sports, running, falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint dislocations, and fractures. ...

Prosthetic ankle push-off work reduces metabolic rate but not collision work in non-amputee walking

Science.gov (United States)

Caputo, Joshua M.; Collins, Steven H.

2014-12-01

Individuals with unilateral below-knee amputation expend more energy than non-amputees during walking and exhibit reduced push-off work and increased hip work in the affected limb. Simple dynamic models of walking suggest a possible solution, predicting that increasing prosthetic ankle push-off should decrease leading limb collision, thereby reducing overall energy requirements. We conducted a rigorous experimental test of this idea wherein ankle-foot prosthesis push-off work was incrementally varied in isolation from one-half to two-times normal levels while subjects with simulated amputation walked on a treadmill at 1.25 m.s-1. Increased prosthesis push-off significantly reduced metabolic energy expenditure, with a 14% reduction at maximum prosthesis work. In contrast to model predictions, however, collision losses were unchanged, while hip work during swing initiation was decreased. This suggests that powered ankle push-off reduces walking effort primarily through other mechanisms, such as assisting leg swing, which would be better understood using more complete neuromuscular models.

Leg-adjustment strategies for stable running in three dimensions

International Nuclear Information System (INIS)

Peuker, Frank; Maufroy, Christophe; Seyfarth, André

2012-01-01

The dynamics of the center of mass (CoM) in the sagittal plane in humans and animals during running is well described by the spring-loaded inverted pendulum (SLIP). With appropriate parameters, SLIP running patterns are stable, and these models can recover from perturbations without the need for corrective strategies, such as the application of additional forces. Rather, it is sufficient to adjust the leg to a fixed angle relative to the ground. In this work, we consider the extension of the SLIP to three dimensions (3D SLIP) and investigate feed-forward strategies for leg adjustment during the flight phase. As in the SLIP model, the leg is placed at a fixed angle. We extend the scope of possible reference axes from only fixed horizontal and vertical axes to include the CoM velocity vector as a movement-related reference, resulting in six leg-adjustment strategies. Only leg-adjustment strategies that include the CoM velocity vector produced stable running and large parameter domains of stability. The ability of the model to recover from perturbations along the direction of motion (directional stability) depended on the strategy for lateral leg adjustment. Specifically, asymptotic and neutral directional stability was observed for strategies based on the global reference axis and the velocity vector, respectively. Additional features of velocity-based leg adjustment are running at arbitrary low speed (kinetic energy) and the emergence of large domains of stable 3D running that are smoothly transferred to 2D SLIP stability and even to 1D SLIP hopping. One of the additional leg-adjustment strategies represented a large convex region of parameters where stable and robust hopping and running patterns exist. Therefore, this strategy is a promising candidate for implementation into engineering applications, such as robots, for instance. In a preliminary comparison, the model predictions were in good agreement with the experimental data, suggesting that the 3D SLIP is an

Arm to leg coordination in elite butterfly swimmers.

Science.gov (United States)

Chollet, D; Seifert, L; Boulesteix, L; Carter, M

2006-04-01

This study proposed the use of four time gaps to assess arm-to-leg coordination in the butterfly stroke at increasing race paces. Fourteen elite male swimmers swam at four velocities corresponding to the appropriate paces for, respectively, the 400-m, 200-m, 100-m, and 50-m events. The different stroke phases of the arm and leg were identified by video analysis and then used to calculate four time gaps (T1: time gap between entry of the hands in the water and the high break-even point of the first undulation; T2: time gap between the beginning of the hands' backward movement and the low break-even point of the first undulation; T3: time gap between the hands' arrival in a vertical plane to the shoulders and the high break-even point of the second undulation; T4: time gap between the hands' release from the water and the low break-even point of the second undulation), the values of which described the changing relationship of arm to leg movements over an entire stroke cycle. With increases in pace, elite swimmers increased the stroke rate, the relative duration of the arm pull, the recovery and the first downward movement of the legs, and decreased the stroke length, the relative duration of the arm catch phase and the body glide with arms forward (measured by T2), until continuity in the propulsive actions was achieved. Whatever the paces, the T1, T3, and T4 values were close to zero and revealed a high degree of synchronisation at key motor points of the arm and leg actions. This new method to assess butterfly coordination could facilitate learning and coaching by situating the place of the leg undulation in relation with the arm stroke.

Factors Determining the Size of Sealing Clearance in Hydraulic Legs of Powered Supports

Directory of Open Access Journals (Sweden)

Buyalich Gennady

2017-01-01

Full Text Available The factors that directly influence the formation of a sealing clearance between the piston and the working cylinder in hydraulic legs of powered supports are considered in this article, the size thereof has a direct effect on the tightness of the legs and, as a result, on the safety of work at the production face. A detailed description of these factors is given, which is supported by the dependencies obtained from the results of finite element modeling of various types of legs under various strength and geometric parameters, external load types and locations in the support section. The problems of formation of radial deformations of a working cylinder loaded with working fluid pressure are considered, and their dependence on the level of this pressure and extension. Based on the simulation results, the mechanisms for the formation of additional clearances due to rod and cylinder misalignments are described, and the conditions and causes of the resonant phenomena development are given. The classification of these factors according to the degree of generalization and the functional interaction between each other is proposed.

Are the hamstrings from the drive leg or landing leg more active in baseball pitchers? An electromyographic study.

Science.gov (United States)

Erickson, Brandon J; Zaferiou, Antonia; Chalmers, Peter N; Ruby, Deana; Malloy, Phillip; Luchetti, Timothy J; Verma, Nikhil N; Romeo, Anthony A

2017-11-01

Ulnar collateral ligament reconstruction (UCLR) has become a common procedure among baseball players of all levels. There are several graft choices in performing UCLR, one of which is a hamstring (gracilis or semitendinosus) autograft. It is unclear whether the hamstring muscle from a pitcher's drive leg (ipsilateral side of the UCLR) or landing leg (contralateral side of the UCLR) is more active during the pitching motion. We hypothesized that the landing leg semitendinosus will be more electromyographically active than the drive leg. Healthy, elite male pitchers aged 16-21 years were recruited. Sixteen pitchers (average age, 17.6 ± 1.6 years; 67% threw right handed) underwent electromyographic analysis. Pitchers threw 5 fastballs at 100% effort from the wind-up with electromyographic analysis of every pitch. Activation of the semitendinosus and biceps femoris in both legs was compared within pitchers and between pitchers. Hamstring activity was higher in the drive leg than in the landing leg during each phase and in sum, although the difference was significant only during the double support phase (P = .021). On within-pitcher analysis, 10 of 16 pitchers had significantly more sum hamstring activity in the drive leg than in the landing leg, while only 4 of 16 had more activity in the landing leg (P = .043). During the baseball pitch, muscle activity of the semitendinosus was higher in the drive leg than in the landing leg in most pitchers. Surgeons performing UCLR using hamstring autograft should consider harvesting the graft from the pitcher's landing leg to minimize disruption to the athlete's pitching motion. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Phase controlled metal–insulator transition in multi-leg quasiperiodic optical lattices

International Nuclear Information System (INIS)

Maiti, Santanu K.; Sil, Shreekantha; Chakrabarti, Arunava

2017-01-01

A tight-binding model of a multi-leg ladder network with a continuous quasiperiodic modulation in both the site potential and the inter-arm hopping integral is considered. The model mimics optical lattices where ultra-cold fermionic or bosonic atoms are trapped in double well potentials. It is observed that, the relative phase difference between the on-site potential and the inter-arm hopping integral, which can be controlled by the tuning of the interfering laser beams trapping the cold atoms, can result in a mixed spectrum of one or more absolutely continuous subband(s) and point like spectral measures. This opens up the possibility of a re-entrant metal–insulator transition. The subtle role played by the relative phase difference mentioned above is revealed, and we corroborate it numerically by working out the multi-channel electronic transmission for finite two-, and three-leg ladder networks. The extension of the calculation beyond the two-leg case is trivial, and is discussed in the work. - Graphical abstract: ▪ - Highlights: • Phase controlled metal–insulator transition is discussed. • An analytical prescription is given to understand MI transition. • Our work provides a way of designing experiments involving laser beams.

Comparison between Unilateral and Bilateral Plyometric Training on Single and Double Leg Jumping Performance and Strength.

Science.gov (United States)

Bogdanis, Gregory C; Tsoukos, Athanasios; Kaloheri, Olga; Terzis, Gerasimos; Veligekas, Panagiotis; Brown, Lee E

2017-04-18

This study compared the effects of unilateral and bilateral plyometric training on single and double-leg jumping performance, maximal strength and rate of force development (RFD). Fifteen moderately trained subjects were randomly assigned to either a unilateral (U, n=7) or bilateral group (B, n=8). Both groups performed maximal effort plyometric leg exercises two times per week for 6 weeks. The B group performed all exercises with both legs, while the U group performed half the repetitions with each leg, so that total exercise volume was the same. Jumping performance was assessed by countermovement jumps (CMJ) and drop jumps (DJ), while maximal isometric leg press strength and RFD were measured before and after training for each leg separately and both legs together. CMJ improvement with both legs was not significantly different between U (12.1±7.2%) and B (11.0±5.5%) groups. However, the sum of right and left leg CMJ only improved in the U group (19.0±7.1%, pplyometric training was more effective at increasing both single and double-leg jumping performance, isometric leg press maximal force and RFD when compared to bilateral training.

Radiographic detection of single-leg fracture in Björk-Shiley Convexo-Concave prosthetic valves: a phantom model study.

Science.gov (United States)

Gilchrist, I C; Cardella, J F; Fox, P S; Pae, W E; el-Ghamry Sabe, A A; Landis, J R; Localio, A R; Kunselman, A R; Hopper, K D

1997-02-01

Cineradiography can identify patients with single-leg fractured Björk-Shiley Convexo-Concave valves, although little is known about the sensitivity and specificity of this technique. We evaluated three normal and six (0 microm gap) single-leg fractured Björk-Shiley valves that were placed in a working phantom model. Valves were randomly imaged a total of 33 times and duplicated into a 120-valve series with a 1:9 ratio of abnormal/normal valves. Six reviewers independently graded each valve and demonstrated markedly different rates of identifying the fractured valves. Average sensitivity at the grade that clinically results in valve explanation was 47%. Among the normal valves, a correct identification was made 96% (range 91% to 99%) of the time. Present radiographic technology may have significant difficulty in identifying true single-leg fracture in Björk-Shiley valves with limb separations that are common among clinically explanted valves.

Nocturnal variations in lower-leg subcutaneous blood flow in paraplegic men

DEFF Research Database (Denmark)

Sindrup, J H; Wroblewski, H; Kastrup, J

1992-01-01

1. Lower-leg subcutaneous adipose tissue blood flow rates were measured over 12-20 h under ambulatory conditions by means of the 133Xe-washout technique in nine paraplegic men, all with complete spinal cord lesions at or below the Th 6 level, and in nine age-matched healthy men. Portable Cd......Te(Cl) detectors and data-storage units were used. 2. The central and local sympathetic vasoconstrictive activity at the lower leg was measured under laboratory conditions by means of the 133Xe-washout technique and a stationary NaI(Tl) detector system. 3. The paraplegic men were found to have intact central...... the paraplegic men suffered from complete lower-leg somaesthetic denervation. 5. A significant correlation was found between the time of going to bed and the nightly hyperaemic response in the right and left lower legs (P less than 0.01). 6. It is concluded that the present data are in accordance...

Analysis of large break loss of coolant accident with simultaneous injection into cold leg and hot leg

International Nuclear Information System (INIS)

Luo Bangqi

1997-01-01

When a large break loss of coolant accident occurs, the most part of the safety injection water injected into the cold leg by the safety injection system will flow through the channel between the pressure vessel and the barrel out of the break into the containment, only a little part of the safety injection water can flow into the reactor core. If the safety injection can inject into both the cold leg and the hot leg simultaneously, the safety injection water injected from the cold leg will flow into the core more easily, because the safety injection water injected from the hot leg will carry out more heat from the upper plenum and the core, so the upper plenum and the core is depressed. In addition, a small part of the safety injection water injected from the hot leg will flow down in the core after impinging the guide tubes in the upper plenum, so the core will get more safety injection water than only cold leg injection, and the core will be much safer

Biomechanical analysis of the single-leg decline squat

NARCIS (Netherlands)

Zwerver, J.; Bredeweg, S. W.; Hof, A. L.

Background: The single-leg squat on a 25 decline board has been described as a clinical assessment tool and as a rehabilitation exercise for patients with patellar tendinopathy. Several assumptions have been made about its working mechanism on patellar load and patellofemoral forces, but these are

Ambulatory measurement of nocturnal fluctuations in subcutaneous blood flow rate in the lower leg of man during 12-h periods with the portable CdTe(Cl) detector. Methodological considerations

DEFF Research Database (Denmark)

Sindrup, J H; Kastrup, J; Jørgensen, B

1991-01-01

Possible sources of error during long-term measurements of subcutaneous blood flow rate with the portable CdTe(Cl) detector system were ruled out in the present study. Local blood flow rates were recorded in the lower legs of normal human subjects by means of the 133Xe wash-out technique. A good ...

Motor control patterns during an active straight leg raise in pain-free subjects.

Science.gov (United States)

Beales, Darren John; O'Sullivan, Peter Bruce; Briffa, N Kathryn

2009-01-01

Repeated measures. To investigate motor control (MC) patterns of normal subjects during the low level physical load of the active straight leg raise (ASLR). Aberrant MC patterns, as observed with the ASLR test, are considered to be a mechanism for ongoing pain and disability in subjects with chronic musculoskeletal pelvic girdle pain. These patterns may not only affect the provision of lumbopelvic stability, but also respiration and the control of continence. Greater understanding of MC patterns in pain-free subjects may improve the management of pelvic girdle pain. METHODS.: Fourteen pain-free nulliparous women were examined during the ASLR. Electromyography of the anterior abdominal wall, right chest wall and the anterior scaleni, intraabdominal pressure (IAP), intrathoracic pressure (ITP), respiratory rate, pelvic floor kinematics, and downward leg pressure of the nonlifted leg were compared between a left and right ASLR. There was greater activation of obliquus internus abdominis and obliquus externus abdominis on the side of the ASLR. The predominant pattern of activation for the chest wall was tonic activation during an ipsilateral ASLR, and phasic respiratory activation lifting the contralateral leg. Respiratory fluctuation of both IAP and ITP did not differ lifting either leg. The baseline shifts of these pressure variables in response to the physical demand of lifting the leg was also the same either side. There was no difference in respiratory rate, pelvic floor kinematics, or downward leg pressure. Pain-free subjects demonstrate a predominant pattern of greater ipsilateral tonic activation of the abdominal wall and chest wall on the side of the ASLR. This was achieved with minimal apparent disruption to IAP and ITP. The findings of this study demonstrate the plastic nature of the abdominal cylinder and the flexibility of the neuromuscular system in controlling load transference during an ASLR.

Leg og dannelse

DEFF Research Database (Denmark)

Skovbjerg, Helle Marie

2017-01-01

lederen i det pædagogiske tidskrift Asterisk: ”Leg i skolen, leg i klasserummet, ja legende læring i skolen udgør derimod en enorm, seriøs og ubrugt læringsressource – ikke alene med effekter på kreativiteten, men også på den faglige læring” (Holm, 2015, p. 2). Legens værdi gøres altså først og fremmest...

The Motor and the Brake of the Trailing Leg in Human Walking: Leg Force Control Through Ankle Modulation and Knee Covariance

Science.gov (United States)

Toney, Megan E.; Chang, Young-Hui

2016-01-01

Human walking is a complex task, and we lack a complete understanding of how the neuromuscular system organizes its numerous muscles and joints to achieve consistent and efficient walking mechanics. Focused control of select influential task-level variables may simplify the higher-level control of steady state walking and reduce demand on the neuromuscular system. As trailing leg power generation and force application can affect the mechanical efficiency of step-to-step transitions, we investigated how joint torques are organized to control leg force and leg power during human walking. We tested whether timing of trailing leg force control corresponded with timing of peak leg power generation. We also applied a modified uncontrolled manifold analysis to test whether individual or coordinated joint torque strategies most contributed to leg force control. We found that leg force magnitude was adjusted from step-to-step to maintain consistent leg power generation. Leg force modulation was primarily determined by adjustments in the timing of peak ankle plantar-flexion torque, while knee torque was simultaneously covaried to dampen the effect of ankle torque on leg force. We propose a coordinated joint torque control strategy in which the trailing leg ankle acts as a motor to drive leg power production while trailing leg knee torque acts as a brake to refine leg power production. PMID:27334888

A Hydroxyurea-induced Leg Ulcer

OpenAIRE

Hwang, Seon-Wook; Hong, Soon-Kwon; Kim, Sang-Hyun; Seo, Jong-Keun; Lee, Deborah; Sung, Ho-Suk

2009-01-01

Hydroxyurea is a cytostatic agent that has recently become the drug of choice in the treatment of various myeloproliferative diseases. The cutaneous side effects of hydroxyurea include xerosis, hyperpigmentation, nail discoloration, and scaling. Leg ulcers have only rarely been reported in association with hydroxyurea treatment. A 75-year-old woman presented with leg ulcers, nail discoloration, and xerosis. The leg ulcers were refractory to conventional treatment. She had been taking oral hyd...

Comparison of thermoregulatory responses to heat between Malaysian and Japanese males during leg immersion

Science.gov (United States)

Wijayanto, Titis; Wakabayashi, Hitoshi; Lee, Joo-Young; Hashiguchi, Nobuko; Saat, Mohamed; Tochihara, Yutaka

2011-07-01

The objective of this study was to investigate thermoregulatory responses to heat in tropical (Malaysian) and temperate (Japanese) natives, during 60 min of passive heating. Ten Japanese (mean ages: 20.8 ± 0.9 years) and ten Malaysian males (mean ages: 22.3 ± 1.6 years) with matched morphological characteristics and physical fitness participated in this study. Passive heating was induced through leg immersion in hot water (42°C) for 60 min under conditions of 28°C air temperature and 50% RH. Local sweat rate on the forehead and thigh were significantly lower in Malaysians during leg immersion, but no significant differences in total sweat rate were observed between Malaysians (86.3 ± 11.8 g m-2 h-1) and Japanese (83.2 ± 6.4 g m-2 h-1) after leg immersion. In addition, Malaysians displayed a smaller rise in rectal temperature (0.3 ± 0.1°C) than Japanese (0.7 ± 0.1°C) during leg immersion, with a greater increase in hand skin temperature. Skin blood flow was significantly lower on the forehead and forearm in Malaysians during leg immersion. No significant different in mean skin temperature during leg immersion was observed between the two groups. These findings indicated that regional differences in body sweating distribution might exist between Malaysians and Japanese during heat exposure, with more uniform distribution of local sweat rate over the whole body among tropical Malaysians. Altogether, Malaysians appear to display enhanced efficiency of thermal sweating and thermoregulatory responses in dissipating heat loss during heat loading. Thermoregulatory differences between tropical and temperate natives in this study can be interpreted as a result of heat adaptations to physiological function.

Simulation and development of a multi-leg homogeniser concentrating assembly for concentrated photovoltaic (CPV) system with electrical rating analysis

International Nuclear Information System (INIS)

Burhan, Muhammad; Chua, Kian Jon Ernest; Ng, Kim Choon

2016-01-01

Highlights: • Novel multi-leg homogeniser concentrating assembly is developed for CPV system. • Single set of concentrator, concentrates sunlight on 4 MJCs with 1° acceptance angle. • The system performance is analyzed through experiment and ray tracing simulation. • Mini two axis solar tracker, with high tracking accuracy, is developed and tested. • Electrical rating analysis accurately estimates CPV system performance in any region. - Abstract: Concentrated photovoltaic (CPV) system utilizing multi-junction solar cells, is the main focus for current research, offering highest efficiency among all photovoltaic systems. The main aspect of CPV system is the design and performance of concentrating assembly, as it determines the performance of whole CPV system. However, the conventional design of CPV concentrating assembly dedicates one concentrator for each solar cell, in which single concentrator is capable to concentrate solar radiation onto single solar cell. This paper proposes a novel concentrating assembly for CPV system, which is designed to concentrate solar radiation onto four multi-junction solar cells with a single set of concentrators. The proposed design not only can reduce the number of concentrators and assembly efforts for CPV systems, but also achieved an acceptance angle of 1°. In this paper, the proposed multi-leg homogeniser CPV concentrating assembly is designed, developed, experimentally tested and verified through ray tracing simulation. The paper also discuss the development of mini, precise and accurate but cost effective two axis solar tracker for CPV system, which can be installed at any location even at rooftop of residential buildings, unlike conventional large scale CPV systems. Moreover, through the electrical rating analysis of the developed CPV system, its performance can be accurately estimated in any region.

EX1304: Northeast U.S. Canyons Exploration on NOAA Ship Okeanos Explorer between 20130708 and 20130725 (Leg I) and 20130731 and 20130817 (Leg II)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — ROV exploration of the Northeast U.S. Deepwater Canyons complementing and continuing the work of the 2012 ACUMEN expedition. The two legs of EX1304 will perform...

Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study.

Science.gov (United States)

Engelberger, Rolf P; Blazek, Claudia; Amsler, Felix; Keo, Hong H; Baumann, Frédéric; Blättler, Werner; Baumgartner, Iris; Willenberg, Torsten

2011-10-05

Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female) in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD) and whole limb (limbBF) volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW), and as intra-class correlation coefficients (ICC). A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both). At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58%) for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79%) for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P correction formula permitted further improvement of CVW. Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula.

Reproducibility and day time bias correction of optoelectronic leg volumetry: a prospective cohort study

Directory of Open Access Journals (Sweden)

Baumgartner Iris

2011-10-01

Full Text Available Abstract Background Leg edema is a common manifestation of various underlying pathologies. Reliable measurement tools are required to quantify edema and monitor therapeutic interventions. Aim of the present work was to investigate the reproducibility of optoelectronic leg volumetry over 3 weeks' time period and to eliminate daytime related within-individual variability. Methods Optoelectronic leg volumetry was performed in 63 hairdressers (mean age 45 ± 16 years, 85.7% female in standing position twice within a minute for each leg and repeated after 3 weeks. Both lower leg (legBD and whole limb (limbBF volumetry were analysed. Reproducibility was expressed as analytical and within-individual coefficients of variance (CVA, CVW, and as intra-class correlation coefficients (ICC. Results A total of 492 leg volume measurements were analysed. Both legBD and limbBF volumetry were highly reproducible with CVA of 0.5% and 0.7%, respectively. Within-individual reproducibility of legBD and limbBF volumetry over a three weeks' period was high (CVW 1.3% for both; ICC 0.99 for both. At both visits, the second measurement revealed a significantly higher volume compared to the first measurement with a mean increase of 7.3 ml ± 14.1 (0.33% ± 0.58% for legBD and 30.1 ml ± 48.5 ml (0.52% ± 0.79% for limbBF volume. A significant linear correlation between absolute and relative leg volume differences and the difference of exact day time of measurement between the two study visits was found (P W. Conclusions Leg volume changes can be reliably assessed by optoelectronic leg volumetry at a single time point and over a 3 weeks' time period. However, volumetry results are biased by orthostatic and daytime-related volume changes. The bias for day-time related volume changes can be minimized by a time-correction formula.

Toward Balance Recovery With Leg Prostheses Using Neuromuscular Model Control

Science.gov (United States)

Geyer, Hartmut

2016-01-01

Objective Lower limb amputees are at high risk of falling as current prosthetic legs provide only limited functionality for recovering balance after unexpected disturbances. For instance, the most established control method used on powered leg prostheses tracks local joint impedance functions without taking the global function of the leg in balance recovery into account. Here we explore an alternative control policy for powered transfemoral prostheses that considers the global leg function and is based on a neuromuscular model of human locomotion. Methods We adapt this model to describe and simulate an amputee walking with a powered prosthesis using the proposed control, and evaluate the gait robustness when confronted with rough ground and swing leg disturbances. We then implement and partially evaluate the resulting controller on a leg prosthesis prototype worn by a non-amputee user. Results In simulation, the proposed prosthesis control leads to gaits that are more robust than those obtained by the impedance control method. The initial hardware experiments with the prosthesis prototype show that the proposed control reproduces normal walking patterns qualitatively and effectively responds to disturbances in early and late swing. However, the response to mid-swing disturbances neither replicates human responses nor averts falls. Conclusions The neuromuscular model control is a promising alternative to existing prosthesis controls, although further research will need to improve on the initial implementation and determine how well these results transfer to amputee gait. Significance This work provides a potential avenue for future development of control policies that help improve amputee balance recovery. PMID:26315935

The bothersomeness of sciatica: patients' self-report of paresthesia, weakness and leg pain.

Science.gov (United States)

Grøvle, Lars; Haugen, Anne Julsrud; Keller, Anne; Natvig, Bård; Brox, Jens Ivar; Grotle, Margreth

2010-02-01

The objective of the study was to investigate how patients with sciatica due to disc herniation rate the bothersomeness of paresthesia and weakness as compared to leg pain, and how these symptoms are associated with socio-demographic and clinical characteristics. A cross-sectional study was conducted on 411 patients with clinical signs of radiculopathy. Items from the Sciatica Bothersomeness Index (0 = none to 6 = extremely) were used to establish values for paresthesia, weakness and leg pain. Associations with socio-demographic and clinical variables were analyzed by multiple linear regression. Mean scores (SD) were 4.5 (1.5) for leg pain, 3.4 (1.8) for paresthesia and 2.6 (2.0) for weakness. Women reported higher levels of bothersomeness for all three symptoms with mean scores approximately 10% higher than men. In the multivariate models, more severe symptoms were associated with lower physical function and higher emotional distress. Muscular paresis explained 19% of the variability in self-reported weakness, sensory findings explained 10% of the variability in paresthesia, and straight leg raising test explained 9% of the variability in leg pain. In addition to leg pain, paresthesia and weakness should be assessed when measuring symptom severity in sciatica.

Aesthetic refinements in reconstructive microsurgery of the lower leg.

Science.gov (United States)

Rainer, Christian; Schwabegger, Anton H; Gardetto, Alexander; Schoeller, Thomas; Hussl, Heribert; Ninkovic, Milomir M

2004-02-01

Even if a surgical procedure is performed for reconstructive and functional reasons, a plastic surgeon must be responsible for the visible result of the work and for the social reintegration of the patient; therefore, the aesthetic appearance of a microsurgically reconstructed lower leg must be considered. Based on the experience of 124 free-tissue transfers to the lower leg performed in 112 patients between January 1994 and March 2001 (110 [88.7 percent] were transferred successfully), three cases are presented. Considerations concerning flap selection and technical refinements in designing and tailoring microvascular flaps to improve the quality of reconstruction, also according to the aesthetic appearance, are discussed.

Pipe crawler with extendable legs

International Nuclear Information System (INIS)

Zollinger, W.T.

1992-01-01

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs

Pipe crawler with extendable legs

Science.gov (United States)

Zollinger, W.T.

1992-06-16

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

Effects of payment method on work control, work risk and work-related musculoskeletal health among sewing machine operators

Directory of Open Access Journals (Sweden)

R. Nawawi

2015-12-01

, forearm, and leg (p<0.005, df=1. The musculoskeletal pain in these regions were reported more often by the piece rate wage group than the time rate wage group (At shoulder; OR = 2.94 with 95% confidence interval (CI: 1.39-6.20, at lower back OR = 3.16 with 95% CI: 1.74-5.74, at forearm OR = 2.55 with 95% CI: 1.56-4.17, at hip OR = 2.49 with 95% CI: 1.52-4.07 and at leg OR = 2.97 with 95% CI: 1.72-5.15. It can be concluded that the type of wage system could be one of the contributory factors in a high prevalence of WRMSD and high ergonomic physical work risks among sewing machine operators. It is recommended that sewing machine operators are better off being paid via a time rate wage system compared to a piece rate wage system to reduce work risks and WRMSD among them.

Leg som ustyrlig deltagelseskultur

DEFF Research Database (Denmark)

Toft, Herdis

2017-01-01

- og spilteoretikere Johan Huizinga og Roger Caillois. Deres teorier og begrebsdannelser har været brugt til at påpege leg dels som et æstetisk baseret betydningssystem, dels som et affektivt og stemningsbaseret oplevelsessystem samt endelig som et socialt baseret relationssystem. I artiklen vælger vi...... at fokusere på leg som et socialt baseret relationssystem og yderligere zoome ind på et af legens systemiske væsenstræk, nemlig brugen af regulerbare regelsæt, som legerne uden ’politi’ forhandler sig frem til før, under og efter legen. Fælles for Huizinga og Caillois er, at de knytter leg uløseligt sammen...

Voluntary movement frequencies in submaximal one- and two-legged knee extension exercise and pedaling

Directory of Open Access Journals (Sweden)

Julie Sørbø Stang

2016-02-01

Full Text Available Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n=16, thereof 8 women; 23.4±2.7 years; 1.70±0.11 m; 68.6±11.2 kg.High and fair correlations (R-values of 0.99 and 0.75 occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95 occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence.The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs

Muscle fatigue and exhaustion during dynamic leg exercise in normoxia and hypobaric hypoxia

DEFF Research Database (Denmark)

Fulco, C S; Lewis, S F; Frykman, Peter

1996-01-01

and during exercise. MVC force was 578 +/- 29 N in normoxia and 569 +/- 29 N in hypobaria before exercise and fell, at exhaustion, to similar levels (265 +/- 10 and 284 +/- 20 N for normoxia and hypobaria, respectively; P > 0.05) that were higher (P ...Using an exercise device that integrates maximal voluntary static contraction (MVC) of knee extensor muscles with dynamic knee extension, we compared progressive muscle fatigue, i.e., rate of decline in force-generating capacity, in normoxia (758 Torr) and hypobaric hypoxia (464 Torr). Eight...... healthy men performed exhaustive constant work rate knee extension (21 +/- 3 W, 79 +/- 2 and 87 +/- 2% of 1-leg knee extension O2 peak uptake for normoxia and hypobaria, respectively) from knee angles of 90-150 degrees at a rate of 1 Hz. MVC (90 degrees knee angle) was performed before dynamic exercise...

Legāti

OpenAIRE

Segliņa, Aiga

2010-01-01

Autore teorētiski analizē legāta jēdzienu testamentārās mantošanas ietvaros un atspoguļo praktiska pētījuma rezultātus. Teorētiskā daļa apskata legāta nodibināšanas formu un spēkā esamību, tā iegūšanu un atraidīšanu, izpildi un zaudēšanu, novēlējuma robežas un aprobežojumus. Pētījums veikts aptaujas veidā ar mērķi noskaidrot, cik liela Latvijas iedzīvotāju daļa apzinās legāta nodrošinātās priekšrocības testamentārajā mantošanā. Apskatīts notāra neitralitātes jautājums attiecībā pret mantošana...

Leak-before-break due to fatigue cracks in the cold leg piping system

International Nuclear Information System (INIS)

Mayfield, M.E.; Collier, R.P.

1984-01-01

This review paper presents the results of a deterministic assessment of the margin of safety against a large break in the cold leg piping system of pressurized water reactors. The paper focuses on the computation of leak rates resulting from fatigue cracks that penetrate the full wall thickness. Results are presented that illustrate the sensitivity of the leak rate to stress level, crack shape and crack orientation. Further, the leak rates for specific conditions are contrasted to detection levels, shutdown criteria, make-up capacity and the leak rate associated with final failure of the piping system. The results of these computations indicate that, in general, leaks far in excess of the present detection sensitivities would result at crack sizes well below the critical crack sizes for the upset loadings on the cold leg piping system

Immediate effects of the trunk stabilizing exercise on static balance parameters in double-leg and one-leg stances

OpenAIRE

Kim, Jwa-jun; Park, Se-yeon

2016-01-01

[Purpose] The purpose of this study was to evaluate the immediate effect of stabilizing exercise using the PNF technique on standing balance in one-leg and double-leg stances. [Subjects and Methods] The present study recruited 34 healthy participants from a local university. The Participants performed four balance tests (double-leg stance with and without vision, one-leg stance with and without vision), before and after exercise. The exercise consisted of exercises performed using PNF techniq...

Effect of Leg-to-Body Ratio on Body Shape Attractiveness.

Science.gov (United States)

Kiire, Satoru

2016-05-01

Recent studies have examined various aspects of human physical attractiveness. Attractiveness is considered an evolved psychological mechanism acquired via natural selection because an attractive body reflects an individual's health and fertility. The length of the legs is an often-emphasized aspect of attractiveness and has been investigated using the leg-to-body ratio (LBR), which reflects nutritional status of the infant, health status, fecundity, and other factors that are predictive of physical fitness. However, previous studies of leg length and physical fitness have produced mixed results. The present study investigated the relationship between LBR, defined as the height to perineum divided by total height, and perceived attractiveness. Three-dimensional stimuli (11 male and 11 female) were constructed with various LBR features. Each stimulus was rated by 40 women and 40 men in Japan on a 7-point scale. The results showed that the values closest to the average LBRs were rated as the most attractive. Furthermore, by fitting a quadratic curve on the relationship between attractiveness and LBR, an inverted U-shaped curve with the peak located at the average LBR was observed. In addition, high LBR values were rated as more attractive in females, whereas the opposite was true for males. These results suggest that average LBR is indicative of good health and good reproductive potential, whereas more extreme values are avoided because they could be indicative of diseases and other maladaptive conditions.

Artificial Leg Design and Control Research of a Biped Robot with Heterogeneous Legs Based on PID Control Algorithm

Directory of Open Access Journals (Sweden)

Hualong Xie

2015-04-01

Full Text Available A biped robot with heterogeneous legs (BRHL is proposed to provide an ideal test-bed for intelligent bionic legs (IBL. To make artificial leg gait better suited to a human, a four-bar mechanism is used as its knee joint, and a pneumatic artificial muscle (PAM is used as its driving source. The static mathematical model of PAM is established and the mechanical model of a single degree of freedom of a knee joint driven by PAM is analyzed. A control simulation of an artificial leg based on PID control algorithm is carried out and the simulation results indicate that the artificial leg can simulate precisely a normal human walking gait.

Near-Infrared Spectroscopic Measurement of the Effect of Leg Dominance on Muscle Oxygen Saturation During Cycling

Science.gov (United States)

Ellerby, Gwenn E. C.; Lee, Stuart M. C.; Paunescu, Lelia Adelina; Pereira, Chelsea; Smith, Charles P.; Soller, Babs R.

2011-01-01

The effect of leg dominance on the symmetry of the biomechanics during cycling remains uncertain -- asymmetries have been observed in kinematics and kinetics, while symmetries were found in muscle activation. No studies have yet investigated the symmetry of muscle metabolism during cycling. Near-infrared spectroscopy (NIRS) provides a non-invasive method to investigate the metabolic responses of specific muscles during cycling. PURPOSE: To determine whether there was an effect of leg dominance on thigh muscle oxygen saturation (SmO2) during incrementally loaded submaximal cycling using NIRS. METHODS: Eight right leg dominant, untrained subjects (5 men, 3 women; 31+/-2 yrs; 168.6+/-1.0 cm; 67.2+/-1.8 kg, mean +/- SE) volunteered to participate. Spectra were collected bilaterally from the vastus lateralis (VL) during supine rest and cycling. SmO2 was calculated using previously published methods. Subjects pedaled at 65 rpm while resistance to pedaling was increased in 0.5 kp increments from 0.5 kp every 3 min until the subject reached 80% of age-predicted maximal heart rate. SmO2 was averaged over 3 min for each completed stage. A two-way ANOVA was performed to test for leg differences. A priori contrasts were used to compare work levels to rest. RESULTS: VL SmO2 was not different between the dominant and non-dominant legs at rest and during exercise (p=0.57). How SmO2 changed with workload was also not different between legs (p=0.32). SmO2 at 0.5 kp (60.3+/-4.0, p=0.12) and 1.0 kp (59.5+/-4.0, p=0.10) was not different from rest (69.1+/-4.0). SmO2 at 1.5 kp (55.4 4.0, p=0.02), 2.0 kp (55.7+/-5.0, p=0.04), and 2.5 kp (43.4+/-7.9, p=0.01) was significantly lower than rest. CONCLUSION: VL SmO2 during cycling is not different between dominant and non-dominant legs and decreases with moderate workload in untrained cyclists. Assuming blood flow is directed equally to both legs, similar levels of oxygen extraction (as indicated by SmO2) suggests the metabolic load of

The bothersomeness of sciatica: patients’ self-report of paresthesia, weakness and leg pain

Science.gov (United States)

Haugen, Anne Julsrud; Keller, Anne; Natvig, Bård; Brox, Jens Ivar; Grotle, Margreth

2009-01-01

The objective of the study was to investigate how patients with sciatica due to disc herniation rate the bothersomeness of paresthesia and weakness as compared to leg pain, and how these symptoms are associated with socio-demographic and clinical characteristics. A cross-sectional study was conducted on 411 patients with clinical signs of radiculopathy. Items from the Sciatica Bothersomeness Index (0 = none to 6 = extremely) were used to establish values for paresthesia, weakness and leg pain. Associations with socio-demographic and clinical variables were analyzed by multiple linear regression. Mean scores (SD) were 4.5 (1.5) for leg pain, 3.4 (1.8) for paresthesia and 2.6 (2.0) for weakness. Women reported higher levels of bothersomeness for all three symptoms with mean scores approximately 10% higher than men. In the multivariate models, more severe symptoms were associated with lower physical function and higher emotional distress. Muscular paresis explained 19% of the variability in self-reported weakness, sensory findings explained 10% of the variability in paresthesia, and straight leg raising test explained 9% of the variability in leg pain. In addition to leg pain, paresthesia and weakness should be assessed when measuring symptom severity in sciatica. PMID:19488793

Robust and efficient walking with spring-like legs

Energy Technology Data Exchange (ETDEWEB)

Rummel, J; Blum, Y; Seyfarth, A, E-mail: juergen.rummel@uni-jena.d, E-mail: andre.seyfarth@uni-jena.d [Lauflabor Locomotion Laboratory, University of Jena, Dornburger Strasse 23, 07743 Jena (Germany)

2010-12-15

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

Robust and efficient walking with spring-like legs

International Nuclear Information System (INIS)

Rummel, J; Blum, Y; Seyfarth, A

2010-01-01

The development of bipedal walking robots is inspired by human walking. A way of implementing walking could be performed by mimicking human leg dynamics. A fundamental model, representing human leg dynamics during walking and running, is the bipedal spring-mass model which is the basis for this paper. The aim of this study is the identification of leg parameters leading to a compromise between robustness and energy efficiency in walking. It is found that, compared to asymmetric walking, symmetric walking with flatter angles of attack reveals such a compromise. With increasing leg stiffness, energy efficiency increases continuously. However, robustness is the maximum at moderate leg stiffness and decreases slightly with increasing stiffness. Hence, an adjustable leg compliance would be preferred, which is adaptable to the environment. If the ground is even, a high leg stiffness leads to energy efficient walking. However, if external perturbations are expected, e.g. when the robot walks on uneven terrain, the leg should be softer and the angle of attack flatter. In the case of underactuated robots with constant physical springs, the leg stiffness should be larger than k-tilde = 14 in order to use the most robust gait. Soft legs, however, lack in both robustness and efficiency.

An exploration of current leg ulcer management practices in an Irish community setting.

Science.gov (United States)

Clarke-Moloney, M; Keane, N; Kavanagh, E

2006-10-01

To establish the prevalence of leg ulceration in the Irish Health Service Executive (HSE) mid-western region and to determine the level of assessment and treatment patients have been receiving in the local community. Before the introduction of a Doppler training programme, all public health and community health nurses working in the Irish HSE mid-western area were requested to complete an audit form on each patient being treated for leg ulceration during a predefined one-week period. This form recorded details on patient demographics, ulcer aetiology, assessment and treatment. Out of 97 nurses, 96 responded to this audit, giving a response rate of 98.9%. A total of 429 patients with 449 leg ulcers were identified. Mean age was 75.5 years (standard deviation 10.7). Overall prevalence was 0.12%, which increased to 1.2% in those aged 70 years and over. Women were almost twice as likely as men to be affected (ratio of 1.8:1). The main causes of ulceration were reported as venous incompetence accounting for 63.3% (284/449) and arterial insufficiency accounting for 8% (36/449) of all ulcers. Only 59.9% (269/449) of all ulcerated limbs had ABPI measurements performed. Of those reported as venous in origin, 71.8% (204/284) had ABPI measurements recorded. Evidence-based care was generally apparent in this group, with 47.5% (97/204) receiving high compression and 18.1% (37/204) receiving reduced compression. However, in venous leg ulcers where ABPIs were not recorded (n=80) care appeared haphazard and inappropriate. Our study has identified the benefit of ABPI Doppler assessment.This assessment could be done in local health centres by trained nurses who could provide more appropriate and timely care to patients, thereby improving outcomes and relieving pressure on acute hospital clinics.

Don't break a leg: running birds from quail to ostrich prioritise leg safety and economy on uneven terrain.

Science.gov (United States)

Birn-Jeffery, Aleksandra V; Hubicki, Christian M; Blum, Yvonne; Renjewski, Daniel; Hurst, Jonathan W; Daley, Monica A

2014-11-01

Cursorial ground birds are paragons of bipedal running that span a 500-fold mass range from quail to ostrich. Here we investigate the task-level control priorities of cursorial birds by analysing how they negotiate single-step obstacles that create a conflict between body stability (attenuating deviations in body motion) and consistent leg force-length dynamics (for economy and leg safety). We also test the hypothesis that control priorities shift between body stability and leg safety with increasing body size, reflecting use of active control to overcome size-related challenges. Weight-support demands lead to a shift towards straighter legs and stiffer steady gait with increasing body size, but it remains unknown whether non-steady locomotor priorities diverge with size. We found that all measured species used a consistent obstacle negotiation strategy, involving unsteady body dynamics to minimise fluctuations in leg posture and loading across multiple steps, not directly prioritising body stability. Peak leg forces remained remarkably consistent across obstacle terrain, within 0.35 body weights of level running for obstacle heights from 0.1 to 0.5 times leg length. All species used similar stance leg actuation patterns, involving asymmetric force-length trajectories and posture-dependent actuation to add or remove energy depending on landing conditions. We present a simple stance leg model that explains key features of avian bipedal locomotion, and suggests economy as a key priority on both level and uneven terrain. We suggest that running ground birds target the closely coupled priorities of economy and leg safety as the direct imperatives of control, with adequate stability achieved through appropriately tuned intrinsic dynamics. © 2014. Published by The Company of Biologists Ltd.

Leg Regrowth in Blaberus discoidalis (Discoid Cockroach) following Limb Autotomy versus Limb Severance and Relevance to Neurophysiology Experiments

Science.gov (United States)

Marzullo, Timothy C.

2016-01-01

Background Many insects can regenerate limbs, but less is known about the regrowth process with regard to limb injury type. As part of our neurophysiology education experiments involving the removal of a cockroach leg, 1) the ability of Blaberus discoidalis cockroaches to regenerate a metathoracic leg was examined following autotomy at the femur/trochanter joint versus severance via a transverse coxa-cut, and 2) the neurophysiology of the detached legs with regard to leg removal type was studied by measuring spike firing rate and microstimulation movement thresholds. Leg Regrowth Results First appearance of leg regrowth was after 5 weeks in the autotomy group and 12 weeks in the coxa-cut group. Moreover, regenerated legs in the autotomy group were 72% of full size on first appearance, significantly larger (pbarbs, and a 10% higher electrical microstimulation threshold for movement. Summary It is recommended that neurophysiology experiments on cockroach legs remove the limb at autotomy joints instead of coxa cuts, as the leg regenerates significantly faster when autotomized and does not detract from the neurophysiology educational content. PMID:26824931

Leg intravenous pressure during head-up tilt.

NARCIS (Netherlands)

Groothuis, J.T.; Poelkens, F.; Wouters, C.W.; Kooijman, H.M.; Hopman, M.T.E.

2008-01-01

Leg vascular resistance is calculated as the arterial-venous pressure gradient divided by blood flow. During orthostatic challenges it is assumed that the hydrostatic pressure contributes equally to leg arterial, as well as to leg venous pressure. Because of venous valves, one may question whether,

Doppler ultrasound exam of an arm or leg

Science.gov (United States)

Peripheral vascular disease - Doppler; PVD - Doppler; PAD - Doppler; Blockage of leg arteries - Doppler; Intermittent claudication - Doppler; Arterial insufficiency of the legs - Doppler; Leg pain and ...

Assessment of the vibration on the foam legged and sheet metal-legged passenger seat

Directory of Open Access Journals (Sweden)

L. Dahil

2015-10-01

Full Text Available In this study, it was aim ed to decrease the vibration reaching to passenger from the legs of vehicle seats. In order to determine the levels of vibrations reaching at passengers, a test pad placed under the passenger seat was used, and HVM100 device was used for digitizing the information obtained. By transferring the vibration data to system by using HVM100 device, the acceleration graphics were prepared with Blaze software. As a result, it was determined that the acceleration values of seat legs made of foam material were lower than that of seat legs made of 2 mm thick sheet metal, so they damped the vibration better.

Frustrated S = 1/2 Two-Leg Ladder with Different Leg Interactions

Science.gov (United States)

Tonegawa, Takashi; Okamoto, Kiyomi; Hikihara, Toshiya; Sakai, Tôru

2017-04-01

We explore the ground-state phase diagram of the S = 1/2 two-leg ladder. The isotropic leg interactions J1,a and J1,b between nearest neighbor spins in the legs a and b, respectively, are different from each other. The xy and z components of the uniform rung interactions are denoted by Jr and ΔJr, respectively, where Δ is the XXZ anisotropy parameter. This system has a frustration when J1,aJ1,b employ the physical consideration, the level spectroscopy analysis of the results obtained by the exact diagonalization method and also the density-matrix renormalization-group method. It is found that the non-collinear ferrimagnetic (NCFR) state appears as the ground state in the frustrated region of the parameters. Furthermore, the direct-product triplet-dimer (TD) state in which all rungs form the TD pair is the exact ground state, when J1,a + J1,b = 0 and 0≤ Δ ≲ 0.83. The obtained phase diagrams consist of the TD, XY and Haldane phases as well as the NCFR phase.

Lower Leg Anterior and Lateral Intracompartmental Pressure Changes Before and After Classic Versus Skate Nordic Rollerskiing.

Science.gov (United States)

Woods, Katherine M; Petron, David J; Shultz, Barry B; Hicks-Little, Charlie A

2015-08-01

Chronic exertional compartment syndrome (CECS) is a debilitating condition resulting in loss of function and a decrease in athletic performance. Cases of CECS are increasing among Nordic skiers; therefore, analysis of intracompartmental pressures (ICPs) before and after Nordic skiing is warranted. To determine if lower leg anterior and lateral ICPs and subjective lower leg pain levels increased after a 20-minute Nordic rollerskiing time trial and to examine if differences existed between postexercise ICPs for the 2 Nordic rollerskiing techniques, classic and skate. Crossover study. Outdoor paved loop. Seven healthy Division I Nordic skiers (3 men, 4 women; age = 22.71 ± 1.38 y, height = 175.36 ± 6.33 cm, mass = 70.71 ± 6.58 kg). Participants completed two 20-minute rollerskiing time trials using the classic and skate technique in random order. The time trials were completed 7 days apart. Anterior and lateral ICPs and lower leg pain scores were obtained at baseline and at minutes 1 and 5 after rollerskiing. Anterior and lateral ICPs (mm Hg) were measured using a Stryker Quic STIC handheld monitor. Subjective measures of lower leg pain were recorded using the 11-point Numeric Rating Scale. Increases in both anterior (P = .000) and lateral compartment (P = .002) ICPs were observed, regardless of rollerskiing technique used. Subjective lower leg pain increased after the classic technique for the men from baseline to 1 minute postexercise and after the skate technique for the women. Significant 3-way interactions (technique × time × sex) were observed for the anterior (P = .002) and lateral (P = .009) compartment ICPs and lower leg pain (P = .005). Postexercise anterior and lateral ICPs increased compared with preexercise ICPs after both classic and skate rollerskiing techniques. Lower leg pain is a primary symptom of CECS. The subjective lower leg pain 11-point Numeric Rating Scale results indicate that increases in lower leg ICPs sustained during Nordic

[Problems and complications of leg lengthening with the Wagner apparatus].

Science.gov (United States)

Herzog, R; Hefti, F

1992-06-01

Since 1971, we have performed 189 leg lengthening procedures using the Wagner method at our institution. The results obtained in the first 26 cases (1971-1973) showed a high complication rate, which led us to reconsider the indications for this procedure. In the present paper, we analyze the results of 37 leg lengthening procedures carried out in 32 patients during the last 10 years (1981-1990) in the children's unit of the orthopedic department of the University of Basle. We found a complication rate of 78%, and in 46% of cases there was more than one major complication. We did not distinguish between "complications" and "problems", because such distinctions are of little importance to the patient. The average age at the time of surgery was 14.8 years, and the average increase in length was 4.3 (2.2-9.2) cm. For each 1 cm of lengthening, an average of 21 days in hospital and 64 days of reduced weight-bearing were needed. Our conclusion is that the Wagner method makes it possible to attain the goal of leg lengthening, but the second step cannot reduce the length of stay in hospital or the length of time the patient needs the help of crutches. Bone remodeling is disturbed. Our preliminary experience with the Ilizarov method is more encouraging.

Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football.

Science.gov (United States)

Hart, Nicolas H; Nimphius, Sophia; Spiteri, Tania; Cochrane, Jodie L; Newton, Robert U

2016-06-01

Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2) each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15) and inaccurate (n = 16) kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701). Relative lean mass was positively correlated with kicking accuracy (r = 0.631), while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083). Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy. Key pointsAccurate kickers expressed a very strong inverse relationship between leg mass and foot velocity. Inaccurate kickers were unable to replicate this, with greater volatility in their performance, indicating an ability of accurate kickers to mediate foot velocity to compensate for leg mass in order to deliver the ball over the required distance.Accurate kickers exhibited larger quantities of relative lean mass and lower quantities

A randomised clinical trial of the efficacy of drop squats or leg extension/leg curl exercises to treat clinically diagnosed jumper's knee in athletes: pilot study

Science.gov (United States)

Cannell, L; Taunton, J; Clement, D; Smith, C; Khan, K

2001-01-01

Objectives—To compare the therapeutic effect of two different exercise protocols in athletes with jumper's knee. Methods—Randomised clinical trial comparing a 12 week programme of either drop squat exercises or leg extension/leg curl exercises. Measurement was performed at baseline and after six and 12 weeks. Primary outcome measures were pain (visual analogue scale 1–10) and return to sport. Secondary outcome measures included quadriceps and hamstring moment of force using a Cybex II isokinetic dynamometer at 30°/second. Differences in pain response between the drop squat and leg extension/curl treatment groups were assessed by 2 (group) x 3 (time) analysis of variance. Two by two contingency tables were used to test differences in rates of return to sport. Analysis of variance (2 (injured versus non-injured leg) x 2 (group) x 3 (time)) was also used to determine differences for secondary outcome measures. Results—Over the 12 week intervention, pain diminished by 2.3 points (36%) in the leg extension/curl group and 3.2 points (57%) in the squat group. There was a significant main effect of both exercise protocols on pain (psquat group returned to sporting activity by 12 weeks, but five of those subjects still had low level pain. Six of nine of the leg extension/curl group returned to sporting activity by 12 weeks and four patients had low level pain. There was no significant difference between groups in numbers returning to sporting activity. There were no differences in the change in quadriceps or hamstring muscle moment of force between groups. Conclusions—Progressive drop squats and leg extension/curl exercises can reduce the pain of jumper's knee in a 12 week period and permit a high proportion of patients to return to sport. Not all patients, however, return to sport by that time. Key Words: knee; patellar tendon; tendinopathy; tendinosis; eccentric strengthening; strength training PMID:11157465

Duplex sonography of the near-surface leg veins

International Nuclear Information System (INIS)

Mendoza, E.

2007-01-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins

The kinematic differences between off-spin and leg-spin bowling in cricket.

Science.gov (United States)

Beach, Aaron J; Ferdinands, René E D; Sinclair, Peter J

2016-09-01

Spin bowling is generally coached using a standard technical framework, but this practice has not been based upon a comparative biomechanical analysis of leg-spin and off-spin bowling. This study analysed the three-dimensional (3D) kinematics of 23 off-spin and 20 leg-spin bowlers using a Cortex motion analysis system to identify how aspects of the respective techniques differed. A multivariate ANOVA found that certain data tended to validate some of the stated differences in the coaching literature. Off-spin bowlers had a significantly shorter stride length (p = 0.006) and spin rate (p = 0.001), but a greater release height than leg-spinners (p = 0.007). In addition, a number of other kinematic differences were identified that were not previously documented in coaching literature. These included a larger rear knee flexion (p = 0.007), faster approach speed (p < 0.001), and flexing elbow action during the arm acceleration compared with an extension action used by most of the off-spin bowlers. Off-spin and leg-spin bowlers also deviated from the standard coaching model for the shoulder alignment, front knee angle at release, and forearm mechanics. This study suggests that off-spin and leg-spin are distinct bowling techniques, supporting the development of two different coaching models in spin bowling.

Scaling of avian bipedal locomotion reveals independent effects of body mass and leg posture on gait.

Science.gov (United States)

Daley, Monica A; Birn-Jeffery, Aleksandra

2018-05-22

Birds provide an interesting opportunity to study the relationships between body size, limb morphology and bipedal locomotor function. Birds are ecologically diverse and span a large range of body size and limb proportions, yet all use their hindlimbs for bipedal terrestrial locomotion, for at least some part of their life history. Here, we review the scaling of avian striding bipedal gaits to explore how body mass and leg morphology influence walking and running. We collate literature data from 21 species, spanning a 2500× range in body mass from painted quail to ostriches. Using dynamic similarity theory to interpret scaling trends, we find evidence for independent effects of body mass, leg length and leg posture on gait. We find no evidence for scaling of duty factor with body size, suggesting that vertical forces scale with dynamic similarity. However, at dynamically similar speeds, large birds use relatively shorter stride lengths and higher stride frequencies compared with small birds. We also find that birds with long legs for their mass, such as the white stork and red-legged seriema, use longer strides and lower swing frequencies, consistent with the influence of high limb inertia on gait. We discuss the observed scaling of avian bipedal gait in relation to mechanical demands for force, work and power relative to muscle actuator capacity, muscle activation costs related to leg cycling frequency, and considerations of stability and agility. Many opportunities remain for future work to investigate how morphology influences gait dynamics among birds specialized for different habitats and locomotor behaviors. © 2018. Published by The Company of Biologists Ltd.

Leg pain

Science.gov (United States)

... in the blood Medicines (such as diuretics and statins) Muscle fatigue or strain from overuse, too much exercise, or holding a muscle in the same position for a long time An injury can also cause leg pain from: A torn or overstretched muscle ( strain ) Hairline ...

Broken Leg

Science.gov (United States)

... the leg, which can result in a fracture. Stress fractures outside of sport situations are more common in people who have: ... shoes. Choose the appropriate shoe for your favorite sports or activities. And ... can prevent stress fractures. Rotate running with swimming or biking. If ...

Not letting the left leg know what the right leg is doing: limb-specific locomotor adaptation to sensory-cue conflict.

Science.gov (United States)

Durgin, Frank H; Fox, Laura F; Hoon Kim, Dong

2003-11-01

We investigated the phenomenon of limb-specific locomotor adaptation in order to adjudicate between sensory-cue-conflict theory and motor-adaptation theory. The results were consistent with cue-conflict theory in demonstrating that two different leg-specific hopping aftereffects are modulated by the presence of conflicting estimates of self-motion from visual and nonvisual sources. Experiment 1 shows that leg-specific increases in forward drift during attempts to hop in place on one leg while blindfolded vary according to the relationship between visual information and motor activity during an adaptation to outdoor forward hopping. Experiment 2 shows that leg-specific changes in performance on a blindfolded hopping-to-target task are similarly modulated by the presence of cue conflict during adaptation to hopping on a treadmill. Experiment 3 shows that leg-specific aftereffects from hopping additionally produce inadvertent turning during running in place while blindfolded. The results of these experiments suggest that these leg-specific locomotor aftereffects are produced by sensory-cue conflict rather than simple motor adaptation.

Quantifying Leg Movement Activity During Sleep.

Science.gov (United States)

Ferri, Raffaele; Fulda, Stephany

2016-12-01

Currently, 2 sets of similar rules for recording and scoring leg movement (LM) exist, including periodic LM during sleep (PLMS) and periodic LM during wakefulness. The former were published in 2006 by a task force of the International Restless Legs Syndrome Study Group, and the second in 2007 by the American Academy of Sleep Medicine. This article reviews the basic recording methods, scoring rules, and computer-based programs for PLMS. Less frequent LM activities, such as alternating leg muscle activation, hypnagogic foot tremor, high-frequency LMs, and excessive fragmentary myoclonus are briefly described. Copyright © 2016 Elsevier Inc. All rights reserved.

Leg ulcers due to hyperhomocysteinemia

Directory of Open Access Journals (Sweden)

Krupa Shankar D

2006-01-01

Full Text Available Chronic leg ulcers are rare in young adults and generally indicate a vascular cause. We report a case of a 26-year-old man with leg ulcers of eight months duration. Doppler study indicated venous incompetence and a postphlebitic limb. However, as the distribution and number of ulcers was not consistent with stasis alone and no features of collagen vascular disease were noted, a hyperviscosity state was considered and confirmed with significantly elevated homocysteine level in the serum. Administration of vitamins B1, B2, B6 and B12, trimethyl-glycine, mecobalamine, folic acid and povidone iodine dressings with culture-directed antibiotic therapy led to a satisfactory healing of ulcers over a period of one month. Hyperhomocysteinemia must be considered in the differential diagnosis of leg ulcers in young individuals.

Bioinspired template-based control of legged locomotion

OpenAIRE

Ahmad Sharbafi, Maziar

2018-01-01

cient and robust locomotion is a crucial condition for the more extensive use of legged robots in real world applications. In that respect, robots can learn from animals, if the principles underlying locomotion in biological legged systems can be transferred to their artificial counterparts. However, legged locomotion in biological systems is a complex and not fully understood problem. A great progress to simplify understanding locomotion dynamics and control was made by introducing simple mo...

Theoretical study of hydraulic jump during circular horizontal hot leg injection in pressurized water reactor

International Nuclear Information System (INIS)

El Hawary, Shehab; Abu-Elyazeed, Osayed S.M.; Fahmy, Adel Alyan; Meglaa, Khairy

2016-01-01

Highlights: • The model is developed to predict the occurrence of onset hydraulic jump in a circular pipe. • Theoretical results are in agreement with experimental results and theory. • Effects of diameter of the injection pipe, Froude number and injected coolant mass are studied. - Abstract: One important phenomenon occurring during Loss of Coolant Accident (LOCA) is Counter-Current Flow Limitation (CCFL). The incidence of such CCFL is introduced by the onset of hydraulic jump. In the present work, a one dimensional model was modified to fit circular hot channel. The model was used to study the factors affecting the initial Froude number, the location of the occurrence of the hydraulic jump, and the critical coolant flow depth during circular horizontal hot leg injection in US-APWR Mitsubishi Reactor. The results showed good agreement with published experimental data of the Upper Plenum Test Facility (UPTF) at Mannheim, Germany. It was found that higher injected coolant mass flow rate increases the initial Froude number, the location of the occurrence of the hydraulic jump, and the critical injection depth divided by the diameter of the injection pipe. Such behavior is thought to be due to the increase of the inertia force by increasing of the injected coolant mass flow rate and the inverse of the diameter of the injection pipe. It was found also that, the location of the occurrence of hydraulic jump increases with decreasing load effect. Therefore, these results reveal that the avoidance of CCFL as well as hydraulic jump through hot leg at maximum load can be achieved by decreasing the distance between the injection point and the pressure vessel to below 0.3 m, and with diameter of 4 in (10.16 cm) as the design diameter of the injection pipe in US-APWR Mitsubishi Reactor. Moreover, the maximum critical depth (56 cm) is less than the diameter of the hot leg (78.74 cm) at an injected coolant mass flow of 400 kg/s, and with diameter of 4 in (10.16 cm) as the

The relationship of temperature rise to specific absorption rate and current in the human leg for exposure to electromagnetic radiation in the high frequency band

International Nuclear Information System (INIS)

Wainwright, P R

2003-01-01

Of the biological effects of human exposure to radiofrequency and microwave radiation, the best-established are those due to elevation of tissue temperature. To prevent harmful levels of heating, restrictions have been proposed on the specific absorption rate (SAR). However, the relationship between SAR and temperature rise is not an invariant, since not only the heat capacity but also the efficiency of heat dissipation varies between different tissues and exposure scenarios. For small enough SAR, the relationship is linear and may be characterized by a 'heating factor'. Under whole-body irradiation the SAR may be particularly high in the ankles due to the concentration of current flowing through a relatively small cross-sectional area. In a previous paper, the author has presented calculations of the SAR distribution in a human leg in the high frequency (HF) band. In this paper, the heating factor for this situation is derived using a finite element approximation of the Pennes bio-heat equation. The sensitivity of the results to different blood perfusion rates is investigated, and a simple local thermoregulatory model is applied. Both time-dependent and steady-state solutions are considered. Results confirm the appropriateness of the ICNIRP reference level of 100 mA on current through the leg, but suggest that at higher currents significant thermoregulatory adjustments to muscle blood flow will occur

The effect of starting or stopping skin cooling on the thermoregulatory responses during leg exercise in humans.

Science.gov (United States)

Demachi, K; Yoshida, T; Kume, M; Tsuneoka, H

2012-07-01

To assess the effects of starting or stopping leg cooling on the thermoregulatory responses during exercise, 60 min of cycling exercise at 30% of maximal oxygen uptake was performed under 4 conditions using tube trouser perfused with water at 10 °C; no leg cooling (NC), starting of leg cooling after 30 min of exercise (delayed cooling, DC), continuous leg cooling (CC), and stopping of continuous leg cooling after 30 min of exercise (SC) at an environmental temperature of 28.5 °C. During exercise under the DC conditions, an instantaneous increase in the esophageal temperature (Tes), a suppression of the cutaneous vascular conductance at the forearm (%CVC), and a decrease in the mean skin temperature (Tsk) were observed after leg cooling. The total sweat loss (Δm sw,tot) was lower under the DC than the NC condition. In the SC study, however, the Tes remained constant, while the %CVC increased gradually after leg cooling was stopped, and the Δm sw,tot was greater than that under the CC condition. These results suggest that during exercise, rapid skin cooling of the leg may cause an increase in core temperature, while also enhancing thermal stress. However, stopping skin cooling did not significantly affect the core temperature long-term, because the skin blood flow and sweat rate subsequently increased. © Georg Thieme Verlag KG Stuttgart · New York.

INTRA-RATER RELIABILITY OF THE MULTIPLE SINGLE-LEG HOP-STABILIZATION TEST AND RELATIONSHIPS WITH AGE, LEG DOMINANCE AND TRAINING.

Science.gov (United States)

Sawle, Leanne; Freeman, Jennifer; Marsden, Jonathan

2017-04-01

Balance is a complex construct, affected by multiple components such as strength and co-ordination. However, whilst assessing an athlete's dynamic balance is an important part of clinical examination, there is no gold standard measure. The multiple single-leg hop-stabilization test is a functional test which may offer a method of evaluating the dynamic attributes of balance, but it needs to show adequate intra-tester reliability. The purpose of this study was to assess the intra-rater reliability of a dynamic balance test, the multiple single-leg hop-stabilization test on the dominant and non-dominant legs. Intra-rater reliability study. Fifteen active participants were tested twice with a 10-minute break between tests. The outcome measure was the multiple single-leg hop-stabilization test score, based on a clinically assessed numerical scoring system. Results were analysed using an Intraclass Correlations Coefficient (ICC 2,1 ) and Bland-Altman plots. Regression analyses explored relationships between test scores, leg dominance, age and training (an alpha level of p = 0.05 was selected). ICCs for intra-rater reliability were 0.85 for the dominant and non-dominant legs (confidence intervals = 0.62-0.95 and 0.61-0.95 respectively). Bland-Altman plots showed scores within two standard deviations. A significant correlation was observed between the dominant and non-dominant leg on balance scores (R 2 =0.49, ptest demonstrated strong intra-tester reliability with active participants. Younger participants who trained more, have better balance scores. This test may be a useful measure for evaluating the dynamic attributes of balance. 3.

Adaptive leg coordination with a biologically inspired neurocontroller

Science.gov (United States)

Braught, Grant; Thomopoulos, Stelios C.

1996-10-01

Natural selection is responsible for the creation of robust and adaptive control systems. Nature's control systems are created only from primitive building blocks. Using insect neurophysiology as a guide, a neural architecture for leg coordination in a hexapod robot has been developed. Reflex chains and sensory feedback mechanisms from various insects and crustacea form the basis of a pattern generator for intra-leg coordination. The pattern generator contains neural oscillators which learn from sensory feedback to produce stepping patterns. Using sensory feedback as the source of learning information allows the pattern generator to adapt to changes in the leg dynamics due to internal or external causes. A coupling between six of the single leg pattern generators is used to produce the inter-leg coordination necessary to establish stable gaits.

Børns leg og eksperimenterende virksomhed

DEFF Research Database (Denmark)

Damgaard Warrer, Sarah; Broström, Stig

Børns leg og eksperimenterende virksomhed er et rigt felt med mange perspektiver, indgangsvinkler og nuancer. I denne bog kædes leg og det eksperimenterende og skabende sammen som to gensidigt forbundne fænomener og belyses i pædagogisk og didaktisk perspektiv. Desuden beskrives potentialet i båd...

Computer program SCAP-BR for gamma-ray streaming through multi-legged ducts

International Nuclear Information System (INIS)

Byoun, T.Y.; Babel, P.J.; Dajani, A.T.

1977-01-01

A computer program, SCAP-BR, has been developed at Burns and Roe for the gamma-ray streaming analysis through multi-legged ducts. SCAP-BR is a modified version of the single scattering code, SCAP, incorporating capabilities of handling multiple scattering and volumetric source geometries. It utilizes the point kernel integration method to calculate both the line-of-sight and scattered gamma dose rates by employing the ray tracing technique through complex shield geometries. The multiple scattering is handled by a repeated process of the single scatter method through each successive scatter region and collapsed pseudo source meshes constructed on the relative coordinate systems. The SCAP-BR results have been compared with experimental data for a Z-type (three-legged) concrete duct with a Co-60 source placed at the duct entrance point. The SCAP-BR dose rate predictions along the duct axis demonstrate an excellent agreement with the measured values

Localized specific absorption rate calculations in a realistic phantom leg at 1-30 MHz using a finite element method

International Nuclear Information System (INIS)

Wainwright, P.R.

1999-01-01

Protection standards for radiofrequency electromagnetic radiation are principally intended to avoid detrimental thermal effects. To this end the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and national bodies such as the National Radiological Protection Board (NRPB), recommend limitations on the localized specific energy absorption rate (SAR) in various parts of the body. The role of numerical dosimetry is to estimate the SAR from measurable parameters such as external field strengths and total body currents. In recent years there have been significant advances in the sophistication of the anatomical models available, and in our knowledge of the electrical properties of the body tissues. Several groups, including NRPB, have developed mathematical phantoms from medical imaging data, such as MRI scans. It has been known for some time that under certain circumstances SAR restrictions may be violated in the ankle due to the concentration of current in a small area. In this paper the author presents calculations of the SAR distribution in a human leg in the high-frequency (HF) band. This band contains the human whole-body resonance frequency and therefore gives the strongest coupling of the body to the field. The present study uses a finite element model with variable mesh size, derived from a 2 mm resolution voxel phantom of the whole body. It also uses recently acquired data on the electrical properties of the tissues. The results are discussed in the light of the exposure standards promulgated by national and international bodies such as NRPB and ICNIRP, and it is shown that the basic SAR restrictions in the leg are ensured by a current reference level of 100 mA. (author)

Impulsive ankle push-off powers leg swing in human walking.

Science.gov (United States)

Lipfert, Susanne W; Günther, Michael; Renjewski, Daniel; Seyfarth, Andre

2014-04-15

Rapid unloading and a peak in power output of the ankle joint have been widely observed during push-off in human walking. Model-based studies hypothesize that this push-off causes redirection of the body center of mass just before touch-down of the leading leg. Other research suggests that work done by the ankle extensors provides kinetic energy for the initiation of swing. Also, muscle work is suggested to power a catapult-like action in late stance of human walking. However, there is a lack of knowledge about the biomechanical process leading to this widely observed high power output of the ankle extensors. In our study, we use kinematic and dynamic data of human walking collected at speeds between 0.5 and 2.5 m s(-1) for a comprehensive analysis of push-off mechanics. We identify two distinct phases, which divide the push-off: first, starting with positive ankle power output, an alleviation phase, where the trailing leg is alleviated from supporting the body mass, and second, a launching phase, where stored energy in the ankle joint is released. Our results show a release of just a small part of the energy stored in the ankle joint during the alleviation phase. A larger impulse for the trailing leg than for the remaining body is observed during the launching phase. Here, the buckling knee joint inhibits transfer of power from the ankle to the remaining body. It appears that swing initiation profits from an impulsive ankle push-off resulting from a catapult without escapement.

Restless Legs Syndrome -- Self-Tests and Diagnosis

Science.gov (United States)

... legs syndrome Diagnosis Talk to a board certified sleep medicine physician if you think you have restless legs ... He or she can refer you to a sleep medicine physician if necessary. The sleep physician may ask ...

Six-legged walking robot for service operations

OpenAIRE

Ihme, T.; Schneider, A.; Schmucker, U.

1998-01-01

This paper presents the control system of a six-legged vehicle including force control. Considered control schemes are control of forces and control of body motion. The experimental result with a six-legged robot is presented.

Sensitivity of sensor-based sit-to-stand peak power to the effects of training leg strength, leg power and balance in older adults.

Science.gov (United States)

Regterschot, G Ruben H; Folkersma, Marjanne; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

2014-01-01

Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS peak power and related measures are sensitive to the effects of increasing leg strength, leg power and overall balance in older adults. A further aim was to compare sensitivity between sensor-based STS measures and standard clinical measures of leg strength, leg power, balance, mobility and fall risk, following an exercise-based intervention. To achieve these aims, 26 older adults (age: 70-84 years) participated in an eight-week exercise program aimed at improving leg strength, leg power and balance. Before and after the intervention, performance on normal and fast STS transfers was evaluated with a hybrid motion sensor worn on the hip. In addition, standard clinical tests (isometric quadriceps strength, Timed Up and Go test, Berg Balance Scale) were performed. Standard clinical tests as well as sensor-based measures of peak power, maximal velocity and duration of normal and fast STS showed significant improvements. Sensor-based measurement of peak power, maximal velocity and duration of normal STS demonstrated a higher sensitivity (absolute standardized response mean (SRM): ≥ 0.69) to the effects of training leg strength, leg power and balance than standard clinical measures (absolute SRM: ≤ 0.61). Therefore, the presented sensor-based method appears to be useful for detecting changes in mobility and fall risk. Copyright © 2013 Elsevier B.V. All rights reserved.

Improving venous leg ulcer management

OpenAIRE

Weller, Carolina Dragica

2017-01-01

This thesis reports several different methods to develop and evaluate complex interventions designed to improve venous leg ulcer management. Chronic venous leg ulcers (VLU) are the most common chronic wound problem in the community. Its health and economic burden is predicted to increase due to ageing of the community and increase in prevalence of diabetes and obesity. Although many patients seek health care for VLU, most do not receive the most effective management. Patients with this condi...

Assessing Children's Legs and Feet

OpenAIRE

Wedge, John H.

1985-01-01

Shoes are necessary for protection and warmth. Normal children do not require shoes for support. There is no scientific evidence that shoes—‘orthopedic’ or otherwise—influence or alter the growth or shape of the normal child's foot except, perhaps, adversely if they fit poorly. Family physicians must understand common variations of normal foot and leg development if they are to effectively advise and reassure parents about appropriate footwear. Flat feet, knock knees, bow legs, in-toeing, and...

Promethus Hot Leg Piping Concept

International Nuclear Information System (INIS)

AM Girbik; PA Dilorenzo

2006-01-01

The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept

RESTLESS LEGS SYNDROME

Directory of Open Access Journals (Sweden)

Dmitriy Valer'evich Artem'ev

2009-01-01

Full Text Available The paper describes the epidemiology, etiology, pathogenesis, clinical picture, diagnosis, differential diagnosis, and treatment of restless legs syndrome. Recommendations are given how to choose therapeutic modalities and drugs in relation to different factors.

Protection against high intravascular pressure in giraffe legs

DEFF Research Database (Denmark)

Petersen, Karin K; Hørlyck, Arne; Østergaard, Kristine Hovkjær

2013-01-01

The high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. We investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. Ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination....... All three findings can contribute to protection of the capillaries in giraffe legs from a high arterial pressure....... revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. At and distal to this narrowing, the artery constricted spontaneously and in response to norepinephrine and intravascular pressure recordings revealed a dynamic, viscous pressure drop along...

Skipping on uneven ground: trailing leg adjustments simplify control and enhance robustness.

Science.gov (United States)

Müller, Roy; Andrada, Emanuel

2018-01-01

It is known that humans intentionally choose skipping in special situations, e.g. when descending stairs or when moving in environments with lower gravity than on Earth. Although those situations involve uneven locomotion, the dynamics of human skipping on uneven ground have not yet been addressed. To find the reasons that may motivate this gait, we combined experimental data on humans with numerical simulations on a bipedal spring-loaded inverted pendulum model (BSLIP). To drive the model, the following parameters were estimated from nine subjects skipping across a single drop in ground level: leg lengths at touchdown, leg stiffness of both legs, aperture angle between legs, trailing leg angle at touchdown (leg landing first after flight phase), and trailing leg retraction speed. We found that leg adjustments in humans occur mostly in the trailing leg (low to moderate leg retraction during swing phase, reduced trailing leg stiffness, and flatter trailing leg angle at lowered touchdown). When transferring these leg adjustments to the BSLIP model, the capacity of the model to cope with sudden-drop perturbations increased.

Control strategy for energy-efficient bipedal walking with variable leg stiffness

NARCIS (Netherlands)

Visser, L.C.; Stramigioli, Stefano; Carloni, Raffaella

In this work, we propose a hybrid model for a bipedal walker with controlled variable leg stiffness, and a control strategy for stable gait control. The control reference is a passive gait of the limit-case bipedal spring-loaded inverted pendulum model with massless feet, ensuring that the gait is

Cold leg condensation tests. Task C. Steam--water interaction tests

International Nuclear Information System (INIS)

Brodrick, J.R.; Loiselle, V.

1974-03-01

A report is presented of tests to determine the condensation efficiency of ECC water injected into a quality fluid mixture flowing through the cold leg. In particular, a specific objective was to determine if the mixture of ECC water and quality fluid reached thermodynamic equilibrium before exiting the cold leg. Further, the stability of the ECC water/quality fluid interaction would be assessed by interpretation of thermocouple records and utilization of a section of cold leg piping with view ports to film the interaction whenever possible. The cold leg condensation tests showed complete condensation of the 5 lbm/sec steam quality mixtures in the cold leg by the ECC water flows of the test matrix. The cold leg exit fluid temperature remained below the saturation temperature and had good agreement with the predicted cold leg outlet temperature, calculated assuming total condensation. (U.S.)

The effects of growth rate on leg morphology and tibia breaking strength, mineral density, mineral content, and bone ash in broilers.

Science.gov (United States)

Shim, M Y; Karnuah, A B; Mitchell, A D; Anthony, N B; Pesti, G M; Aggrey, S E

2012-08-01

Fast-growing broilers are especially susceptible to bone abnormalities, causing major problems for broiler producers. The cortical bones of fast-growing broilers are highly porous, which may lead to leg deformities. Leg problems were investigated in 6-wk-old Arkansas randombred broilers. Body weight was measured at hatch and at 6 wk. There were 8 different settings of approximately 450 eggs each. Two subpopulations, slow-growing (SG; bottom quarter, n=511) and fast-growing (FG; top quarter, n=545), were created from a randombred population based on their growth rate from hatch until 6 wk of age. At 6 wk of age, the broilers were processed and chilled at 4°C overnight before deboning. Shank (78.27±8.06 g), drum stick (190.92±16.91 g), and thigh weights (233.88±22.66 g) of FG broilers were higher than those of SG broilers (54.39±6.86, 135.39±15.45, and 168.50±21.13 g, respectivly; Ppercentage of ash content (39.76±2.81) of FG broilers was lower than that of SG broilers (39.99±2.67; P=0.173). Fast-growing broiler bones were longer, wider, heavier, stronger, more dense, and contained more ash than SG ones. After all parameters were calculated per unit of final BW at 6 wk, tibia density and bone ash percentage of FG broilers were lower than those of SG broilers.

Quantitation of progressive muscle fatigue during dynamic leg exercise in humans

DEFF Research Database (Denmark)

Fulco, C S; Lewis, S F; Frykman, Peter

1995-01-01

, a product of a contraction rate (1 Hz), force measured at the ankle, and distance of ankle movement from 90 degrees to 150 degrees of KE, was precisely controlled. Lack of rise in myoelectric activity in biceps femoris of the active leg during DKE and MVC was consistent with restriction of muscle action...

Helium exhaust and forced flow effects with both-leg pumping in W-shaped divertor of JT-60U

International Nuclear Information System (INIS)

Sakasai, A.; Takenaga, H.; Higashijima, S.; Kubo, H.; Nakano, T.; Tamai, H.; Sakurai, S.; Akino, N.; Fujita, T.; Asakura, N.; Itami, K.; Shimizu, K.

2001-01-01

The W-shaped divertor of JT-60U was modified from inner-leg pumping to both-leg pumping. After the modification, the pumping rate was improved from 3% with inner-leg pumping to 5% with both-leg pumping in a divertor-closure configuration, which means both separatrixes close to the divertor slots. Efficient helium exhaust was realized in the divertor-closure configuration with both-leg pumping. A global particle confinement time of τ* He =0.4s and τ* He /τ E =3 was achieved in attached ELMy H-mode plasmas. The helium exhaust efficiency with both-leg pumping was extended by 45% as compared with inner-leg pumping. By using central helium fueling with He-beam injection, the helium removal from the core plasma inside the internal transport barrier (ITB) in reversed shear plasmas in the divertor-closure configuration was investigated for the first time. The helium density profiles inside the ITB were peaked as compared with those in ELMy H-mode plasmas. In the case of low recycling divertor, it was difficult to achieve good helium exhaust capability in reversed shear plasmas with ITB. However, the helium exhaust efficiency was improved with high recycling divertor. Carbon impurity reduction was observed by the forced flow with gas puff and effective divertor pumping. (author)

Leg oxygen uptake in the initial phase of intense exercise is slowed by a marked reduction in oxygen delivery

DEFF Research Database (Denmark)

Christensen, Peter Møller; Nyberg, Michael Permin; Mortensen, Stefan Peter

2013-01-01

-extensor exercise (60±3 W) for 4 min in a control setting (CON) and with arterial infusion of L-NMMA and indomethacin in the working leg to reduce blood flow by inhibiting formation of nitric oxide and prostanoids (double blockade; DB). In DB leg blood flow (LBF) and oxygen delivery during the first minute...

Simvastatin-induced nocturnal leg pain disappears with pravastatin substitution

Directory of Open Access Journals (Sweden)

Stojaković Nataša

2013-01-01

Full Text Available Introduction. Statins have similar side effects that do not always occur at the same rate among the various statins. We present a case of simvastatin-induced muscle toxicity that disappeared when pravastatin was substituted for the original drug. Case Outline. A 74-year-old male, a nonsmoker, complained of severe nocturnal leg cramps. The patient also complained that similar painful cramping occurred when he walked rapidly or jogged. Because some components of his lipid panel exceeded the ‘desirable’ range, and as he had a history of myocardial infarction, his family physician prescribed simvastatin (40 mg/day. The patient had taken this medication for the past eight years. The painful nocturnal episodes started two years ago and affected either one or the other leg. Four months ago we discontinued his simvastatin and prescribed pravastatin (80 mg/day. At a follow-up visit six weeks later, the patient reported that his leg pains at night and the pain experienced after brisk walking had disappeared. Four months after the substitution of pravastatin for simvastatin, the patient reported that his complete lack of symptoms had continued. Conclusion. These painful muscle cramps were probably caused by an inadequate vascular supply to the calf and foot muscles. Perhaps a combination of advanced age and atherosclerotic changes created a predisposition for the simvastatin-induced leg cramps. Pravastatin differs from simvastatin in several ways. It is not metabolized by cytochrome P450 (CYP 3A4 oxidases, and thus is not influenced by CYP 3A4 inhibitors like simvastatin. Also, simvastatin is associated with single-nucleotide polymorphisms located within the SLCO1B1 gene on the chromosome 12 and established myopathy, while pravastatin lacks this association. These differences may contribute to increased tolerance to pravastatin in this particular case.

Simvastatin-lnduced nocturnal leg pain disappears with pravastatin substitution.

Science.gov (United States)

Stojaković, Natasa; Igić, Rajko

2013-01-01

Statins have similar side effects that do not always occur at the same rate among the various statins. We present a case of simvastatin-induced muscle toxicity that disappeared when pravastatin was substituted for the original drug. A 74-year-old male, a nonsmoker, complained of severe nocturnal leg cramps. The patient also complained that similar painful cramping occurred when he walked rapidly or jogged. Because some components of his lipid panel exceeded the'desirable' range, and as he had a history of myocardial infarction, his family physician prescribed simvastatin (40 mg/day). The patient had taken this medication for the past eight years. The painful nocturnal episodes started two years ago and affected either one or the other leg. Four months ago we discontinued his simvastatin and prescribed pravastatin (80 mg/day). At a follow-up visit six weeks later, the patient reported that his leg pains at night and the pain experienced after brisk walking had disappeared. Four months after the substitution of pravastatin for simvastatin, the patient reported that his complete lack of symptoms had continued. These painful muscle cramps were probably caused by an inadequate vascular supply to the calf and foot muscles. Perhaps a combination of advanced age and atherosclerotic changes created a predisposition for the simvastatin-induced leg cramps. Pravastatin differs from simvastatin in several ways.l It is not metabolized by cytochrome P450 (CYP) 3A4 oxidases, and thus is not influenced by CYP 3A4 inhibitors like simvastatin. Also, simvastatin is associated with single-nucleotide polymorphisms located within the SLCO1B1 gene on the chromosome 12 and established myopathy, while pravastatin lacks this association. These differences may contribute to increased tolerance to pravastatin in this particular case.

Bio-Inspired Design and Kinematic Analysis of Dung Beetle-Like Legs

DEFF Research Database (Denmark)

Aditya, Sai Krishna Venkata; Ignasov, Jevgeni; Filonenko, Konstantin

2017-01-01

The African dung beetle Scarabaeus galenus can use its front legs to walk and manipulate or form a dung ball. The interesting multifunctional legs have not been fully investigated or even used as inspiration for robot leg design. Thus, in this paper, we present the development of real dung beetle......-like front legs based on biological investigation. As a result, each leg consists of three main segments which were built using 3D printing. The segments were combined with in total four active DOFs in order to mimic locomotion and object manipulation of the beetle. Kinematics analysis of the leg was also...... performed to identify its workspace as well as to design its trajectory. To this end, the study contributes not only novel multifunctional robotic legs but also the methodology of the bio-inspired leg design....

Development of nondestructive measurement of cold work rate, (2)

International Nuclear Information System (INIS)

Kamimura, Hideaki; Igarashi, Miyuki; Satoh, Masakazu; Miura, Makoto

1978-01-01

Cold-worked type 316 stainless steel will be used as fuel cladding material for the proto-type fast reactor MONJU. Cold work rate is an important parameter in swelling behavior of fuel cladding. It has been shown that austenitic stainless steel undergoes martensitic transformation during cold working. Nondestructive evaluation of cold work rate will be expected by measuring residual magnetism produced in the presence of martensitic phase when cold worked austenitic stainless steel is magnetized. In the previous work, the residual magnetism of cladding tubes of type 316 stainless steel was measured. The results have shown high degree of the correlation between residual magnetism and cold work rate. This paper reports the results of measurement on cold-rolled type 316 stainless steel plate samples. Dimensions of the specimens are 100 mm long and 3.5 and 7 mm wide. The apparatus and experimental procedures were similar to the previous work. Good agreement was found between the estimated cold work rate obtained in the previous work and that for cold rolled plate specimens. Measurement of residual magnetism in identical direction with magnetization showed smaller dispersion of data as compared with that in transverse direction. The residual magnetism near specimen surface hardly decreased when the surface of specimen was chemically removed. The reason for the comparative decrease in residual magnetism at 10% and 15% cold work rate is not clear. (Wakatsuki, Y.)

Clinical quality indicators of venous leg ulcers

DEFF Research Database (Denmark)

Kjaer, Monica L; Mainz, Jan; Soernsen, Lars T

2005-01-01

In the clinical setting, diagnosis and treatment of venous leg ulcers can vary considerably from patient to patient. The first step to reducing this variation is to document venous leg ulcer care through use of quantitative scientific documentation principles. This requires the development of val...

Ubx regulates differential enlargement and diversification of insect hind legs.

Directory of Open Access Journals (Sweden)

Najmus Mahfooz

2007-09-01

Full Text Available Differential enlargement of hind (T3 legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug and Acheta domesticus (house cricket. In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs.

A bipedal DNA Brownian motor with coordinated legs.

Science.gov (United States)

Omabegho, Tosan; Sha, Ruojie; Seeman, Nadrian C

2009-04-03

A substantial challenge in engineering molecular motors is designing mechanisms to coordinate the motion between multiple domains of the motor so as to bias random thermal motion. For bipedal motors, this challenge takes the form of coordinating the movement of the biped's legs so that they can move in a synchronized fashion. To address this problem, we have constructed an autonomous DNA bipedal walker that coordinates the action of its two legs by cyclically catalyzing the hybridization of metastable DNA fuel strands. This process leads to a chemically ratcheted walk along a directionally polar DNA track. By covalently cross-linking aliquots of the walker to its track in successive walking states, we demonstrate that this Brownian motor can complete a full walking cycle on a track whose length could be extended for longer walks. We believe that this study helps to uncover principles behind the design of unidirectional devices that can function without intervention. This device should be able to fulfill roles that entail the performance of useful mechanical work on the nanometer scale.

Leg ulcer treatment outcomes with new ovine collagen extracellular matrix dressing: a retrospective case series.

Science.gov (United States)

Bohn, Gregory A; Gass, Kimberly

2014-10-01

The purpose of this study was to describe the rate of closure observed in venous leg ulcers during treatment with ovine collagen extracellular matrix dressings and compression. Fourteen patients with 23 wounds were retrospectively evaluated with respect to healing rates, time to closure, and weekly facility charge fees.

MR angiography of the pelvic and lower leg arteries: starting with time-resolved imaging of the lower leg is recommended

International Nuclear Information System (INIS)

Schmitt, R.; Christopoulos, G.; Brunner, S.; Froehner, S.; Dobritz, M.; Fellner, F.

2001-01-01

58 patients suffering from peripheral arterial vascular disease were examined using contrast-enhanced MR angiography with the intention of optimizing the visualization of lower leg arteries. Different from the customary acquisition order, were first the arteries of the lower legs depicted with three time-resolved phases. Afterwards, the iliacal and femoral vessels were imaged by applying the floating-table technique in two steps. In all cases, the lower leg arteries were depicted without overlying veins. By injecting the contrast agent in two phases, imaging quality of the iliofemoral arteries was not significantly reduced. - In conclusion, we would recommend the hybrid technique of peripheral contrast-enhanced MRA with primarily starting the acquisition of the lower legs in cases of foot infections or ulcerations where the transit time is reduced bi- or unilaterally. (orig.) [de

Restless Legs Syndrome

Science.gov (United States)

... disorder, particularly if they experience onset at an early age; many years may pass before symptoms occur regularly. top What causes restless legs syndrome? In most cases, the cause of RLS is unknown (called primary RLS). However, RLS has a genetic component and ...

Venous leg ulcer patient priorities and quality of care: results of a survey

DEFF Research Database (Denmark)

Kjaer, Monica Linda; Mainz, Jan; Sorensen, Lars Tue

2004-01-01

A comprehensive patient evaluation of quality of care encompasses assessment and patient-rated prioritization of the various provisions of care. One hundred consecutive venous leg ulcer patients treated in a multidisciplinary wound healing center were invited to participate in a cross-sectional s...

Muscle response to leg lengthening during distraction osteogenesis.

Science.gov (United States)

Thorey, Fritz; Bruenger, Jens; Windhagen, Henning; Witte, Frank

2009-04-01

Continuous lengthening of intact muscles during distraction osteogenesis leads to an increase of sarcomeres and enhances the regeneration of tendons and blood vessels. A high distraction rate leads to an excessive leg and muscle lengthening and might cause damages of muscle fibers with fibrosis, necrosis, and muscle weakness. Complications like muscle contractures or atrophy after postoperative immobilization emphazize the importance of muscles and their function in the clinical outcome. In an animal model of distraction osteogenesis, 18 sheep were operated with an external fixator followed by 4 days latency, 21 days distraction (1.25 mm per day) and 51 days consolidation. The anatomical location (gastrocnemius, peroneus tertius, and first flexor digitorum longus muscle), dimension and occurrence of muscular defects were characterized histologically. The callus formation and leg axis was monitored by weekly X-rays. Additionally, serum creatine kinase was analyzed during a distraction and consolidation period. Significant signs of muscle lesions in all three observed muscles can be found postoperatively, whereas normal callus formation and regular leg axis was observed radiologically. The peroneus tertius and first flexor digitorum longus muscles were found to have significantly more signs of fibrosis, inflammatory, and necrosis. Creatine kinase showed two peaks: 4 and 39 days postoperative as an indication of muscle damage and regeneration. The study implicates that muscle damages should be considered when a long-distance distraction osteogenesis is planned. The surgeon should consider these muscle responses and individually discuss a two-stage treatment or additional muscle tendon releases to minimize the risk of muscle damages.

Reliability and relationships among handgrip strength, leg extensor strength and power, and balance in older men.

Science.gov (United States)

Jenkins, Nathaniel D M; Buckner, Samuel L; Bergstrom, Haley C; Cochrane, Kristen C; Goldsmith, Jacob A; Housh, Terry J; Johnson, Glen O; Schmidt, Richard J; Cramer, Joel T

2014-10-01

To quantify the reliability of isometric leg extension torque (LEMVC), rate of torque development (LERTD), isometric handgrip force (HGMVC) and RFD (HGRFD), isokinetic leg extension torque and power at 1.05rad·s(-1) and 3.14rad·s(-1); and explore relationships among strength, power, and balance in older men. Sixteen older men completed 3 isometric handgrips, 3 isometric leg extensions, and 3 isokinetic leg extensions at 1.05rad·s(-1) and 3.14rad·s(-1) during two visits. Intraclass correlation coefficients (ICCs), ICC confidence intervals (95% CI), coefficients of variation (CVs), and Pearson correlation coefficients were calculated. LERTD demonstrated no reliability. The CVs for LERTD and HGRFD were ≤23.26%. HGMVC wasn't related to leg extension torque or power, or balance (r=0.14-0.47; p>0.05). However, moderate to strong relationships were found among isokinetic leg extension torque at 1.05rad·s(-1) and 3.14rad·s(-1), leg extension mean power at 1.05rad·s(-1), and functional reach (r=0.51-0.95; p≤0.05). LERTD and HGRFD weren't reliable and shouldn't be used as outcome variables in older men. Handgrip strength may not be an appropriate surrogate for lower body strength, power, or balance. Instead, perhaps handgrip strength should only be used to describe upper body strength or functionality, which may compliment isokinetic assessments of lower body strength, which were reliable and related to balance. Copyright © 2014 Elsevier Inc. All rights reserved.

ATLAS Cold Leg Top Slot Break Analysis using RELAP5

Energy Technology Data Exchange (ETDEWEB)

Sung, Haejung; Lee, Sang Ik; Park, Ju-Hyun; Choi, Tong-Soo [KEPCO NF, Daejeon (Korea, Republic of)

2016-10-15

U.S. Nuclear Regulatory Commission (US-NRC) has been reviewing the design certification application for APR1400 submitted by Korea Electric Power Corporation (KEPCO). The main concern about cold leg top slot break is that cladding temperature might be increased by core uncover due to four loop seal reformation following flooding of safety injection water. An integral effect test for cold leg top slot break was performed by KAERI (Korea Atomic Energy Research Institute) using ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation), which is a scaled down experimental facility for APR1400. In this study, RELAP5/MOD3.3/Patch04 is assessed by experimental result of ATLAS cold leg top slot break. Also, thermal hydraulic phenomena by four loop seals reformation is observed by RELAP5 result. The RELAP5/MOD3.3/Patch04 is assessed by the experimental result of ATLAS cold leg top slot break. The top slot break is described by offtake model, and the mass flow rate is fairly well estimated. The RELAP5 well predicts the correlation between general trend and four loop seal reformation. The pressure of the core region and the cladding temperature tends to increase during four loop seal reformation due to steam path blockage on four loop seals. It is presumed that the code cannot estimate two phase phenomena by loop seal clearing as same as experiments. In terms of cladding temperature, loop seal reformation due to loop seal elevation of APR1400 does not need to be the issue, since the void fraction at the active top core is maintained over 0.4.

Extension and customization of self-stability control in compliant legged systems

International Nuclear Information System (INIS)

Ernst, M; Blickhan, R; Geyer, H

2012-01-01

Several recent studies on the control of legged locomotion in animal and robot running focus on the influence of different leg parameters on gait stability. In a preceding investigation self-stability controls showing deadbeat behavior could be obtained by studying the dynamics of the system in dependence of the leg orientation carefully adjusted during the flight phase. Such controls allow to accommodate disturbances of the ground level without having to detect them. Here we further this method in two ways. Besides the leg orientation, we allow changes in leg stiffness during flight and show that this extension substantially improves the rejection of ground disturbances. In a human like example the tolerance of random variation in ground level over many steps increased from 3.5% to 35% of leg length. In single steps changes of about 70% leg length (either up or down) could be negotiated. The variable leg stiffness not only allows to start with flat leg orientations maximizing step tolerances but also increase the control subspace. This allows to customize self-stability controls and to consider physical and technical limitations found in animals and robots. (paper)

[Design and application of medical electric leg-raising machine].

Science.gov (United States)

Liang, Jintang; Chen, Jinyuan; Zhao, Zixian; Lin, Jinfeng; Li, Juanhong; Zhong, Jingliang

2017-08-01

Passive leg raising is widely used in clinic, but it lacks of specialized mechanical raise equipment. It requires medical staff to raise leg by hand or requires a multi-functional bed to raise leg, which takes time and effort. Therefore we have developed a new medical electric leg-raising machine. The equipment has the following characteristics: simple structure, stable performance, easy operation, fast and effective, safe and comfortable. The height range of the lifter is 50-120 cm, the range of the angle of raising leg is 10degree angle-80degree angle, the maximum supporting weight is 40 kg. Because of raising the height of the lower limbs and making precise angle, this equipment can completely replace the traditional manner of lifting leg by hand with multi-functional bed to lift patients' leg and can reduce the physical exhaustion and time consumption of medical staff. It can change the settings at any time to meet the needs of the patient; can be applied to the testing of PLR and dynamically assessing the hemodynamics; can prevent deep vein thrombosis and some related complications of staying in bed; and the machine is easy to be cleaned and disinfected, which can effectively avoid hospital acquired infection and cross infection; and can also be applied to emergency rescue of various disasters and emergencies.

Lower Limb Symmetry: Comparison of Muscular Power Between Dominant and Nondominant Legs in Healthy Young Adults Associated With Single-Leg-Dominant Sports.

Science.gov (United States)

Vaisman, Alex; Guiloff, Rodrigo; Rojas, Juan; Delgado, Iris; Figueroa, David; Calvo, Rafael

2017-12-01

Achieving a symmetrical power performance (difference power between the dominant and nondominant legs in healthy young adults, (2) evaluate the effect of a single-leg-dominant sport activity performed at the professional level, and (3) propose a parameter of normality for maximal power difference in the lower limbs of this young adult population. Controlled laboratory study. A total of 78 healthy, male, young adults were divided into 2 groups according to sport activity level. Group 1 consisted of 51 nonathletes (mean ± SD age, 20.8 ± 1.5 years; weight, 71.9 ± 10.5 kg) who participated in less than 8 hours a week of recreational physical activity with nonspecific training; group 2 consisted of 27 single-leg-dominant professional soccer players (age, 18.4 ± 0.6 years; weight, 70.1 ± 7.5 kg) who specifically trained and competed at their particular activity 8 hours or more a week. For assessment of maximal leg power, both groups completed the single-leg squat jump test. Dominance was determined when participants completed 2 of 3 specific tests with the same extremity. Statistical analysis included the Student t test. No statistical difference was found for maximal power between dominant and nondominant legs for nonathletes ( t = -1.01, P = .316) or single-leg-dominant professional soccer players ( t = -1.10, P = .281). A majority (95%) of participants studied showed a power difference of less than 15% between their lower extremities. Among young healthy adults, symmetrical power performance is expected between lower extremities independent of the existence of dominance and difference in sport activity level. A less than 15% difference in power seems to be a proper parameter to define symmetrical power performance assessed by vertical single-leg jump tests.

Flexural characteristics of a stack leg

International Nuclear Information System (INIS)

Cook, J.

1979-06-01

A 30 MV tandem Van de Graaff accelerator is at present under construction at Daresbury Laboratory. The insulating stack of the machine is of modular construction, each module being 860 mm in length. Each live section stack module contains 8 insulating legs mounted between bulkhead rings. The design, fabrication (from glass discs bonded to stainless steel discs using an epoxy film adhesive) and testing of the stack legs is described. (U.K.)

Leg deformation during imaginal ecdysis in the downy emerald, Cordulia aenea (Odonata, Corduliidae).

Science.gov (United States)

Frantsevich, Leonid; Frantsevich, Ludmilla

2018-04-01

A dragonfly larva migrates from the water to the shore, perches on a plant stem and grasps it with strongly flexed legs. Adult legs inside the larval exoskeleton fit to the larval legs joint-to-joint. The adult emerges with stretched legs. During the molt, an imaginal leg must follow all the angles in exuvial joints. In turn, larval apodemes are withdrawn from imaginal legs. We visualized transient shapes of the imaginal legs by the instant fixation of insects at different moments of the molt, photographed isolated exuvial legs with the imaginal legs inside and then removed the exuvial sheath. Instant shapes of the imaginal tibia show sharp intrapodomere bends copying the angle in the larval femoro-tibial joint. The site of bending shifts distad during the molt. This is possible if the imaginal leg is pliable. The same problem of leg squeezing is also common in hemimetabolous insects as well as in other arthropods, whereas holometabolous insects overcome problems of a tight confinement either by using leg pliability in other ways but not squeezing (cyclorrhaphan flies, mosquitoes) or by pulling hardened legs out without change of their pupal zigzag configuration (moths, ants, honey bees). The pupal legs are not intended to grasp any external substrate. Copyright © 2018 Elsevier GmbH. All rights reserved.

Investigation on welding and cutting methods for blanket support legs of fusion experimental reactors

International Nuclear Information System (INIS)

Tokami, Ikuhide; Nakahira, Masataka; Kurasawa, Toshimasa; Sato, Satoshi; Furuya, Kazuyuki; Hatano, Toshihisa; Takatsu, Hideyuki; Kuroda, Toshimasa.

1996-07-01

A toroidally-and poloidally-divided modular blanket has been proposed for a fusion experimental reactor, such as ITER, to enhance its maintainability as well as improve its fabricability. The blanket module, typically the size of 1 m wide, 1-2 m high and 0.4 m deep and the weight of 4 ton, will be supported by support legs which are extruded from back of the module and connected to a 70-100 mm thick strong back plate. The support leg has to withstand large electromagnetic force during plasma disruption and provide the way for in-situ module replacement by remote handling. For the connection method of the support leg to the back plate, a welding approach has been investigated here in terms of its high reliability against the large electromagnetic loads. For the welding approach, the support leg needs to be 70 mm thick, and the working space for welding/cutting heads are limited to 100 mm x 150 mm adjacent to the support leg. Based on a comparison of several welding methods, e.g. NGTIG, NGMIG and laser, NGTIG has been selected as a reference due to its well-established technology and the least R and D required. As for the cutting method, a plasma cutting has been given the highest priority to be pursued because of its compactness and high speed. Through preliminary design studies, the possibility of small welding/cutting heads that will work in the limited space has been shown, and maintenance route for in-situ module replacement with pre-and postfixture of the module has been investigated. Also preliminary R and Ds have resulted in; 1)the welding distortion is predictable according to the shape of weld groove and adjustable to meet the placement requirement of the module first wall, 2)the plasma cut surface can be rewelded without machining, 3)the welding/cutting time will meet the requirement of maintenance time. (author)

Running over unknown rough terrain with a one-legged planar robot

International Nuclear Information System (INIS)

Andrews, Ben; Miller, Bruce; Clark, Jonathan E; Schmitt, John

2011-01-01

The ability to traverse unknown, rough terrain is an advantage that legged locomoters have over their wheeled counterparts. However, due to the complexity of multi-legged systems, research in legged robotics has not yet been able to reproduce the agility found in the animal kingdom. In an effort to reduce the complexity of the problem, researchers have developed single-legged models to gain insight into the fundamental dynamics of legged running. Inspired by studies of animal locomotion, researchers have proposed numerous control strategies to achieve stable, one-legged running over unknown, rough terrain. One such control strategy incorporates energy variations into the system during the stance phase by changing the force-free leg length as a sinusoidal function of time. In this research, a one-legged planar robot capable of implementing this and other state-of-the-art control strategies was designed and built. Both simulated and experimental results were used to determine and compare the stability of the proposed controllers as the robot was subjected to unknown drop and raised step perturbations equal to 25% of the nominal leg length. This study illustrates the relative advantages of utilizing a minimal-sensing, active energy removal control scheme to stabilize running over rough terrain.

Spider diffraction: a comparison of curved and straight legs

International Nuclear Information System (INIS)

Richter, J.L.

1984-01-01

It has been known for some time that, if curved legs rather than the usual straight ones are used in the spider that supports the secondary optics in certain telescopes, the visible diffraction effect is reduced. Fraunhofer theory is used to calculate the diffraction effects due to the curved leg spider. Calculated and photographic diffraction patterns are compared for straight and curved leg spiders

Energetic and Peak Power Advantages of Series Elastic Actuators in an Actuated Prosthetic Leg for Walking and Running

Directory of Open Access Journals (Sweden)

Martin Grimmer

2014-02-01

Full Text Available A monoarticular series elastic actuator (SEA reduces energetic and peak power requirements compared to a direct drive (DD in active prosthetic ankle-foot design. Simulation studies have shown that similar advantages are possible for the knee joint. The aims of this paper were to investigate the advantages of a monoarticular SEA-driven hip joint and to quantify the energetic benefit of an SEA-driven leg (with monoarticular hip, knee and ankle SEAs, assuming that damping (negative power is passively achieved. The hip SEA provided minor energetic advantages in walking (up to 29% compared to the knee and the ankle SEA. Reductions in required peak power were observed only for speeds close to preferred walking speed (18% to 27%. No energetic advantages were found in running, where a DD achieved the best performance when optimizing for energy. Using an SEA at each leg joint in the sagittal plane reduced the positive work by 14% to 39% for walking and by 37% to 75% for running. When using an SEA instead of a DD, the contribution of the three leg joints to doing positive work changed: the knee contributed less and the hip more positive work. For monoarticular SEAs, the ankle joint motor did most of the positive work.

Straight leg elevation to rule out pelvic injury.

Science.gov (United States)

Bolt, Caroline; O'Keeffe, Francis; Finnegan, Pete; Dickson, Kristofer; Smit, De Villiers; Fitzgerald, Mark C; Mitra, Biswadev

2018-02-01

Pelvic x-ray is frequently used as a screening tool during initial assessment of injured patients. However routine use in the awake and alert blunt trauma patient may be questioned due to low yield. We propose a clinical tool that may avoid unnecessary imaging by examining whether the ability to straight leg raise, without pain, can rule out pelvic injury. We conducted a prospective cohort study with the exposure variables of ability to straight leg raise and presence of pain on doing so, and presence of pelvic fracture on x-ray as the primary outcome variable. Of the 328 participants, 35 had pelvic fractures, and of these 32 were either unable to straight leg raise, or had pain on doing so, with a sensitivity of 91.43% (95% CI: 76.94-98.2%) and a negative predictive value of 98.57% (95% CI: 95.88-99.70%). The 3 participants with a pelvic fracture who could straight leg raise with no pain, all had a GCS of less than 15, and therefore, among the sub-group of patients with GCS15, a 100% sensitivity and 100% negative predictive value for straight leg raise with no pain to rule out pelvic fracture was demonstrated. Among awake, alert patients, painless straight leg raise can exclude pelvic fractures and be incorporated into initial examination during reception and resuscitation of injured patients. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Relationship between Leg Mass, Leg Composition and Foot Velocity on Kicking Accuracy in Australian Football

Directory of Open Access Journals (Sweden)

Nicolas H. Hart, Jodie L. Cochrane, Tania Spiteri, Sophia Nimphius, Robert U. Newton

2016-06-01

Full Text Available Kicking a ball accurately over a desired distance to an intended target is arguably the most important skill to acquire in Australian Football. Therefore, understanding the potential mechanisms which underpin kicking accuracy is warranted. The aim of this study was to examine the relationship between leg mass, leg composition and foot velocity on kicking accuracy in Australian Football. Thirty-one Australian Footballers (n = 31; age: 22.1 ± 2.8 years; height: 1.81 ± 0.07 m; weight: 85.1 ± 13.0 kg; BMI: 25.9 ± 3.2 each performed ten drop punt kicks over twenty metres to a player target. Athletes were separated into accurate (n = 15 and inaccurate (n = 16 kicking groups. Leg mass characteristics were assessed using whole body DXA scans. Foot velocity was determined using a ten-camera optoelectronic, three-dimensional motion capture system. Interactions between leg mass and foot velocity evident within accurate kickers only (r = -0.670 to -0.701. Relative lean mass was positively correlated with kicking accuracy (r = 0.631, while no relationship between foot velocity and kicking accuracy was evident in isolation (r = -0.047 to -0.083. Given the evident importance of lean mass, and its interaction with foot velocity for accurate kickers; future research should explore speed-accuracy, impulse-variability, limb co-ordination and foot-ball interaction constructs in kicking using controlled with-in subject studies to examine the effects of resistance training and skill acquisition programs on the development of kicking accuracy.

Modification and Actuator Minimization of the Hip Leg Joint in a Bipedal Robot: A Proposed Design

Directory of Open Access Journals (Sweden)

Nirmalya Tripathi

2014-12-01

Full Text Available In recent times, there have been numeric applications of Biped Robots. In this paper, a proposed upper leg hip design of a biped was developed taking cost reduction and optimization as factors for consideration. The proposed system introduces a novel method which consists of a vibration reduction (VR DC stepper motor, microcontroller, microprocessor and gearing arrangement. The program in the microprocessor is so designed that it gives a fixed number of cycles/steps to the VR DC stepper motor in clockwise and thereafter in anti-clockwise direction. This turning movement can then be transmitted to the gearing system which precisely moves one upper leg when the VR DC stepper motor moves in clockwise direction, while the other upper leg remains static, and vice-versa. It has been observed that this new proposed system may reduce the cost overhead, weight and the energy consumption incurred by working on a single VR DC stepper motor while conventionally two stepper motors are used to give the motion of the two upper legs in a biped.

Leg pain and psychological variables predict outcome 2-3 years after lumbar fusion surgery.

Science.gov (United States)

Abbott, Allan D; Tyni-Lenné, Raija; Hedlund, Rune

2011-10-01

Prediction studies testing a thorough range of psychological variables in addition to demographic, work-related and clinical variables are lacking in lumbar fusion surgery research. This prospective cohort study aimed at examining predictions of functional disability, back pain and health-related quality of life (HRQOL) 2-3 years after lumbar fusion by regressing nonlinear relations in a multivariate predictive model of pre-surgical variables. Before and 2-3 years after lumbar fusion surgery, patients completed measures investigating demographics, work-related variables, clinical variables, functional self-efficacy, outcome expectancy, fear of movement/(re)injury, mental health and pain coping. Categorical regression with optimal scaling transformation, elastic net regularization and bootstrapping were used to investigate predictor variables and address predictive model validity. The most parsimonious and stable subset of pre-surgical predictor variables explained 41.6, 36.0 and 25.6% of the variance in functional disability, back pain intensity and HRQOL 2-3 years after lumbar fusion. Pre-surgical control over pain significantly predicted functional disability and HRQOL. Pre-surgical catastrophizing and leg pain intensity significantly predicted functional disability and back pain while the pre-surgical straight leg raise significantly predicted back pain. Post-operative psychomotor therapy also significantly predicted functional disability while pre-surgical outcome expectations significantly predicted HRQOL. For the median dichotomised classification of functional disability, back pain intensity and HRQOL levels 2-3 years post-surgery, the discriminative ability of the prediction models was of good quality. The results demonstrate the importance of pre-surgical psychological factors, leg pain intensity, straight leg raise and post-operative psychomotor therapy in the predictions of functional disability, back pain and HRQOL-related outcomes.

Two-phase flow experiments in emergency core cooling feed through the hot leg for developing numerical models

International Nuclear Information System (INIS)

Staebler, T.; Meyer, L.; Schulenberg, T.; Laurien, E.

2006-01-01

When a leakage, a 'loss-of-coolant accident', occurs in a light water reactor, the emergency cooling system is able to supply large amounts of coolant to ensure residual heat removal. This supply can be routed through a special emergency cooling pipe, the 'scoop', into the horizontal section of the main coolant pipe, the 'hot leg'. At the same time, hot steam from the superheated, partly voided core flows against the coolant. This gives rise to a two-phase flow in the opposite direction. A factor of primary interest in this situation is whether the coolant supplied by the emergency cooling system will reach the reactor core. The research project is being conducted in order to compute the rate of water supply by numerical methods. The WENKA test facility has been designed and built at the Karlsruhe Research Center to verify numerical calculations. It can be used to study the fluid dynamics phenomena expected to arise in emergency coolant feeding into the hot leg; the necessary local data can be determined experimentally. An extensive database for validating the numerical calculations is then available to complete the experimental work. (orig.)

Volunteer Work, Religious Commitment, and Resting Pulse Rates.

Science.gov (United States)

Krause, Neal; Ironson, Gail; Hill, Peter C

2017-04-01

Research indicates that greater involvement in volunteer activities is associated with better health. We aim to contribute to this literature in two ways. First, rather than rely on self-reports of health, measured resting pulse rates serve as the dependent variable. Second, an effort is made to see if religious commitment moderates the relationship between volunteering and resting pulse rates. Data that come from a recent nationwide survey (N = 2265) suggest that volunteer work is associated with lower resting pulse rates. The results also reveal that the relationship between engaging in volunteer work and resting pulse rates improves among study participants who are more deeply committed to religion.

On the design of a DEA-based device to pot entially assist lower leg disorders: an analytical and FEM investigation accounting for nonlinearities of the leg and device deformations.

Science.gov (United States)

Pourazadi, Shahram; Ahmadi, Sadegh; Menon, Carlo

2015-11-05

One of the recommended treatments for disorders associated with the lower extremity venous insufficiency is the application of external mechanical compression. Compression stockings and elastic bandages are widely used for the purpose of compression therapy and are usually designed to exert a specified value or range of compression on the leg. However, the leg deforms under external compression, which can lead to undesirable variations in the amount of compression applied by the compression bandages. In this paper, the use of an active compression bandage (ACB), whose compression can be regulated through an electrical signal, is investigated. The ACB is based on the use of dielectric elastomer actuators. This paper specifically investigates, via both analytical and non-linear numerical simulations, the potential pressure the ACB can apply when the compliancy of the human leg is taken into account. The work underpins the need to account for the compressibility of the leg when designing compression garments for lower extremity venous insufficiency. A mathematical model is used to simulate the volumetric change of a calf when compressed. Suitable parameters for this calf model are selected from the literature where the calf, from ankle to knee, is divided into six different regions. An analytical electromechanical model of the ACB, which considers its compliancy as a function of its pre-stretch and electricity applied, is used to predict the ACB's behavior. Based on these calf and ACB analytical models, a simulation is performed to investigate the interaction between the ACB and the human calf with and without an electrical stimulus applied to the ACB. This simulation is validated by non-linear analysis performed using a software based on the finite element method (FEM). In all simulations, the ACB's elastomer is stretched to a value in the range between 140 and 220 % of its initial length. Using data from the literature, the human calf model, which is examined in

Exocrine glands in the legs of the social wasp Vespula vulgaris.

Science.gov (United States)

Nijs, Catherine; Billen, Johan

2015-09-01

This study brings a survey of the exocrine glands in the legs of Vespula vulgaris wasps. We studied workers, males, virgin queens as well as mated queens. A variety of 17 glands is found in the different leg segments. Among these, five glands are novel exocrine structures for social insects (trochanter-femur gland, ventrodistal tibial gland, distal tibial sac gland, ventral tibial gland, and ventral tarsomere gland). Most leg glands are present in the three leg pairs of all castes. This may indicate a mechanical function. This is likely for the numerous glands that occur near the articulation between the various leg segments, where lubricant production may be expected. Other possible functions include antenna cleaning, acting as a hydraulic system, or pheromonal. Further research including leg-related behavioural observations and chemical analyses may help to clarify the functions of these glandular structures in the legs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Remission of severe restless legs syndrome and periodic limb movements in sleep after bilateral excision of multiple foot neuromas: a case report

Directory of Open Access Journals (Sweden)

Lettau Ludwig A

2010-09-01

quality index, fatigue severity scale, and the international restless legs syndrome rating scale (36 to 4. Polysomnography six weeks post-operatively showed improved sleep efficiency, a marked increase in rapid eye movement sleep, and marked reductions in hourly rates of both periodic limb movements in sleep with arousal (135.3 to 3.3 and spontaneous arousals (17.3 to 0. Conclusion The immediate and near complete remission of symptoms, the histopathology of the excised tissues, and the marked improvement in polysomnographic parameters documented six weeks after surgery together indicate that this patient's severe restless legs syndrome and periodic limb movements in sleep was of peripheral nerve (foot neuroma origin. Further study of foot neuromas as a source of periodic limb movements in sleep and as a cause of sleep dysfunction in patients with or without concomitant restless legs syndrome, is warranted.

Development and Physical Control Research on Prototype Artificial Leg

Directory of Open Access Journals (Sweden)

Fei Li

2016-03-01

Full Text Available To provide an ideal platform for research on intelligent bionic leg (IBL, this paper proposes a model of a biped robot with heterogeneous legs (BRHL. A prototype of an artificial leg is developed based on biological structure and motion principle analysis of human lower extremities. With regard to the driving sources, servomotors are chosen for the hip joint and ankle joint, while pneumatic muscle actuators (PMAs are chosen for the knee joint. The control system of the bionic artificial leg is designed and a physical experimental platform is established. The physical control experiments are done based on proportional-integral-derivative (PID control strategy. The experimental results show that such a system can realize the expected goals.

Seismic response analysis for hinged-leg type port crane

Energy Technology Data Exchange (ETDEWEB)

Kashiwazaki, A.; Kanayama, T.; Arai, K. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

2000-04-01

Container cranes and unloaders in Kobe Pont were severely damaged during the Southern Hyogo Prefecture Earthquake in 1995. Notably, some of the hinged-leg type of cranes with hinges at the end of sea-or land-side of legs were overturned. These damages were derived from the uplifting of their legs. To explain the uplifting and overturning behavior, we carried out nonlinear analyses and shaking table tests using a 1/8-scale model of the container crane. The results of nonlinear response analyses of hinged-leg type of crane, which are in an agreement with the state of damages in the Southern Hyogo Prefecture Earthquake and the result of shaking table tests, are described. (author)

Anatomic and functional leg-length inequality: A review and recommendation for clinical decision-making. Part I, anatomic leg-length inequality: prevalence, magnitude, effects and clinical significance

Directory of Open Access Journals (Sweden)

Knutson Gary A

2005-07-01

Full Text Available Abstract Background Leg-length inequality is most often divided into two groups: anatomic and functional. Part I of this review analyses data collected on anatomic leg-length inequality relative to prevalence, magnitude, effects and clinical significance. Part II examines the functional "short leg" including anatomic-functional relationships, and provides an outline for clinical decision-making. Methods Online database – Medline, CINAHL and MANTIS – and library searches for the time frame of 1970–2005 were done using the term "leg-length inequality". Results and Discussion Using data on leg-length inequality obtained by accurate and reliable x-ray methods, the prevalence of anatomic inequality was found to be 90%, the mean magnitude of anatomic inequality was 5.2 mm (SD 4.1. The evidence suggests that, for most people, anatomic leg-length inequality does not appear to be clinically significant until the magnitude reaches ~ 20 mm (~3/4". Conclusion Anatomic leg-length inequality is near universal, but the average magnitude is small and not likely to be clinically significant.

Modeling posture-dependent leg actuation in sagittal plane locomotion

International Nuclear Information System (INIS)

Schmitt, J; Clark, J

2009-01-01

The spring loaded inverted pendulum template has been shown to accurately model the steady locomotion dynamics of a variety of running animals, and has served as the inspiration for an entire class of dynamic running robots. While the template models the leg dynamics by an energy-conserving spring, insects and animals have structures that dissipate, store and produce energy during a stance phase. Recent investigations into the spring-like properties of limbs, as well as animal response to drop-step perturbations, suggest that animals use their legs to manage energy storage and dissipation, and that this management is important for gait stability. In this paper, we extend our previous analysis of control of the spring loaded inverted pendulum template via changes in the leg touch-down angle to include energy variations during the stance phase. Energy variations are incorporated through leg actuation that varies the force-free leg length during the stance phase, yet maintains qualitatively correct force and velocity profiles. In contrast to the partially asymptotically stable gaits identified in previous analyses, incorporating energy and leg angle variations in this manner produces complete asymptotic stability. Drop-step perturbation simulations reveal that the control strategy is rather robust, with gaits recovering from drops of up to 30% of the nominal hip height.

A Dung Beetle-like Leg and its Adaptive Neural Control

DEFF Research Database (Denmark)

Di Canio, Giuliano; Stoyanov, Stoyan; Larsen, Jørgen Christian

2016-01-01

Dung beetles show fascinating locomotion abilities. They can use their legs to not only walk but also manipulate objects. Furthermore, they can perform their leg movements at a proper frequency with respect to their biomechanical properties and quickly adapt the movements to deal with external pe...... also apply adaptive neural control, based on a central pattern generator (CPG) circuit with synaptic plasticity, to autonomously generate a proper stepping frequency of the leg. The controller can also adapt the leg movement to deal with external perturbations within a few steps....

New Circuit QED system based on Triple-leg Stripline Resonator.

Science.gov (United States)

Kim, Dongmin; Moon, Kyungsun

Conventional circuit QED system consists of a qubit located inside a linear stripline resonator, which has successfully demonstrated a strong coupling between a single photon and a qubit. Here we present a new circuit QED system, where the qubit is coupled to triple-leg stripline resonator (TSR). We have shown that TSR supports two-fold degenerate photon modes among others. By coupling them to a single qubit, we have obtained the dressed states of a coupled system of a single qubit and two-fold degenerate photon modes. By locating two qubits at two legs of TSR, we have studied a potential two-bit gate operation (e.g., CNOT gate) of the system. We will discuss the main advantage of utilizing two-fold degenerate photon modes This work is partially supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2016R1D1A1B01013756).

Conjoined legs: Sirenomelia or caudal regression syndrome?

Directory of Open Access Journals (Sweden)

Sakti Prasad Das

2013-01-01

Full Text Available Presence of single umbilical persistent vitelline artery distinguishes sirenomelia from caudal regression syndrome. We report a case of a12-year-old boy who had bilateral umbilical arteries presented with fusion of both legs in the lower one third of leg. Both feet were rudimentary. The right foot had a valgus rocker-bottom deformity. All toes were present but rudimentary. The left foot showed absence of all toes. Physical examination showed left tibia vara. The chest evaluation in sitting revealed pigeon chest and elevated right shoulder. Posterior examination of the trunk showed thoracic scoliosis with convexity to right. The patient was operated and at 1 year followup the boy had two separate legs with a good aesthetic and functional results.

Conjoined legs: Sirenomelia or caudal regression syndrome?

Science.gov (United States)

Das, Sakti Prasad; Ojha, Niranjan; Ganesh, G Shankar; Mohanty, Ram Narayan

2013-07-01

Presence of single umbilical persistent vitelline artery distinguishes sirenomelia from caudal regression syndrome. We report a case of a12-year-old boy who had bilateral umbilical arteries presented with fusion of both legs in the lower one third of leg. Both feet were rudimentary. The right foot had a valgus rocker-bottom deformity. All toes were present but rudimentary. The left foot showed absence of all toes. Physical examination showed left tibia vara. The chest evaluation in sitting revealed pigeon chest and elevated right shoulder. Posterior examination of the trunk showed thoracic scoliosis with convexity to right. The patient was operated and at 1 year followup the boy had two separate legs with a good aesthetic and functional results.

Treatment of vasovagal syncope: pacemaker or crossing legs?

NARCIS (Netherlands)

van Dijk, N.; Harms, M. P.; Linzer, M.; Wieling, W.

2000-01-01

A 50-year-old male patient continued to experience syncope after implantation of a pacemaker. During cardiovascular examination, the patient showed a typical vasovagal response, with normal pacemaker function. Leg crossing, which prohibits the pooling of blood in the legs and abdomen, at the onset

Predicting SF-6D utility scores from the Oswestry disability index and numeric rating scales for back and leg pain.

Science.gov (United States)

Carreon, Leah Y; Glassman, Steven D; McDonough, Christine M; Rampersaud, Raja; Berven, Sigurd; Shainline, Michael

2009-09-01

Cross-sectional cohort. The purpose of this study is to provide a model to allow estimation of utility from the Short Form (SF)-6D using data from the Oswestry Disability Index (ODI), Back Pain Numeric Rating Scale (BPNRS), and the Leg Pain Numeric Rating Scale (LPNRS). Cost-utility analysis provides important information about the relative value of interventions and requires a measure of utility not often available from clinical trial data. The ODI and numeric rating scales for back (BPNRS) and leg pain (LPNRS), are widely used disease-specific measures for health-related quality of life in patients with lumbar degenerative disorders. The purpose of this study is to provide a model to allow estimation of utility from the SF-6D using data from the ODI, BPNRS, and the LPNRS. SF-36, ODI, BPNRS, and LPNRS were prospectively collected before surgery, at 12 and 24 months after surgery in 2640 patients undergoing lumbar fusion for degenerative disorders. Spearman correlation coefficients for paired observations from multiple time points between ODI, BPNRS, and LPNRS, and SF-6D utility scores were determined. Regression modeling was done to compute the SF-6D score from the ODI, BPNRS, and LPNRS. Using a separate, independent dataset of 2174 patients in which actual SF-6D and ODI scores were available, the SF-6D was estimated for each subject and compared to their actual SF-6D. In the development sample, the mean age was 52.5 +/- 15 years and 34% were male. In the validation sample, the mean age was 52.9 +/- 14.2 years and 44% were male. Correlations between the SF-6D and the ODI, BPNRS, and LPNRS were statistically significant (P < 0.0001) with correlation coefficients of 0.82, 0.78, and 0.72, respectively. The regression equation using ODI, BPNRS,and LPNRS to predict SF-6D had an R of 0.69 and a root mean square error of 0.076. The model using ODI alone had an R of 0.67 and a root mean square error of 0.078. The correlation coefficient between the observed and estimated

33 CFR 147.809 - Mars Tension Leg Platform safety zone.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Mars Tension Leg Platform safety... SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.809 Mars Tension Leg Platform safety zone. (a) Description. The Mars Tension Leg Platform (Mars TLP) is located at position 28°10′10.29...

The effect of spinal manipulation on imbalances in leg strength.

Science.gov (United States)

Chilibeck, Philip D; Cornish, Stephen M; Schulte, Al; Jantz, Nathan; Magnus, Charlene R A; Schwanbeck, Shane; Juurlink, Bernhard H J

2011-09-01

We hypothesized that spinal manipulation (SM) would reduce strength imbalances between legs. Using an un-blinded randomized design, 28 males and 21 females (54 ± 19y) with at least a 15% difference in isometric strength between legs for hip flexion, extension, abduction, or knee flexion were randomized to treatment or placebo (mock spinal manipulation). Strength of the stronger and weaker legs for hip flexion, extension, abduction, and/or knee flexion was assessed before and after the intervention. SM reduced the relative strength difference between legs for knee flexion (mean ± SD 57 ± 53 to 5 ± 14%) and hip flexion (24 ± 12 to 11 ± 15%) compared to placebo (34 ± 29 to 24 ± 36%, and 20 ± 18 to 22 ± 26%, respectively) (p = 0.05). SM also improved strength in the weak leg for hip abduction (104 ± 43 to 116 ± 43 Nm) compared to placebo (84 ± 24 to 85 ± 31 Nm) (p = 0.03). This study suggests that spinal manipulation may reduce imbalances in strength between legs for knee and hip flexion.

Emphysematous Pyelonephritis Presenting as Necrotizing Fasciitis of the Leg

Directory of Open Access Journals (Sweden)

Yu-Xiong Ye

2009-03-01

Full Text Available We report a 50-year-old man with poorly controlled diabetes mellitus who presented with a painful, swollen right leg. He had also experienced right flank pain for 1 week prior to admission. Physical examination was notable for tenderness over the right flank. The right leg was diffusely swollen and exquisitely tender to touch, with palpable crepitance. Laboratory tests revealed leukocytosis and pyuria. Computed tomography showed a right ureteral stone with hydronephrosis and characteristic findings of emphysematous pyelonephritis. Furthermore, a right perirenal gas-forming abscess with extension to the right leg was noted. The patient was successfully treated with antibiotic therapy, aggressive control of blood sugar, percutaneous drainage of the hydronephrosis and perirenal abscess, and aggressive debridement of the leg.

Secondary hyperparathyroidism: Uncommon cause of a leg ulcer

NARCIS (Netherlands)

van Rijssen, L. B.; Brenninkmeijer, E. E. A.; Nieveen van Dijkum, E. J. M.

2012-01-01

Most leg ulcers are vascular based. Only if vascular therapy fails other causes are considered. We report the case of a female with incapacitating leg ulcers caused by a rare condition which was only diagnosed after failing treatment. PRESENTATION OF CASE: The female had an extensive previous

Dipoles on a Two-leg Ladder

DEFF Research Database (Denmark)

Gammelmark, Søren; Zinner, Nikolaj Thomas

2013-01-01

We study polar molecules with long-range dipole-dipole interactions confined to move on a two-leg ladder for different orientations of the molecular dipole moments with respect to the ladder. Matrix product states are employed to calculate the many-body ground state of the system as function...... that there is a critical angle at which ordering disappears. This angle is slightly larger than the angle at which the dipoles are non-interacting along a single leg. This behavior should be observable using current experimental techniques....

Reasonable designing method for fillet welding leg length

Energy Technology Data Exchange (ETDEWEB)

Kiso, T; Michiyuki, T; Nagao, S; Yoshikawa, M; Miyazaki, S

1976-12-01

In VLCC and ULCC vessels, the scantling of structural members, especially the thickness of web plate, increases naturally. The present rule of each classification society generally prescribes that welding leg length should be based on the thickness of the web plate. Welding leg length between this web plate and skin plate such as shell plate, deck plate, etc., or face plate, increases according to increase of the thickness of the web plate. We investigated the method to decide reasonable welding leg length and its programming by using the results of finite element method structural analysis, without adhering to the above rule about welding leg length. As a result of applying this method to actual ships under classification societies' approval, the amount of welding decreased by from about 10 percent to 15 percent compared with that required by the above rule. The rationality of the method has been already confirmed by successful results of the application to several vessels in service.

Effects of immobility on sensory and motor symptoms of restless legs syndrome.

Science.gov (United States)

Michaud, Martin; Lavigne, Gilles; Desautels, Alex; Poirier, Gaétan; Montplaisir, Jacques

2002-01-01

Restless legs syndrome (RLS) is defined by an irresistible need to move associated with leg paresthesia. Two additional features are essential for diagnosis: (1) worsening of symptoms at rest with temporary relief by activity, and (2) worsening of symptoms during the evening and/or during the night. The suggested immobilization test (SIT) has been developed to evaluate the presence of these criteria. This test quantifies leg movements and leg discomfort during a 1-hour period of immobility prior to bedtime. We used the SIT to evaluate the effects of immobility on leg discomfort and leg movements experienced by 19 patients with RLS and 19 control subjects. Results show that immobility significantly worsens both leg discomfort and periodic leg movements (PLM) in patients with RLS but not in controls. Patients with RLS showed a higher leg discomfort score (32.6 +/- 15.1 mm vs. 5.7 +/- 7.9 mm; P < 0.00001), a greater maximum leg discomfort value (63.4 +/- 27.4 mm vs. 13.7 +/- 23.0 mm; P < 0.00001) and a greater PLM index (88.4 +/- 62.6 vs. 10.4 +/- 20.6; P < 0.00004) than control subjects. These results further validate the use of the SIT as a diagnostic and research tool for RLS and confirm the contention of the International RLS study group that RLS symptoms worsen at rest. Copyright 2001 Movement Disorder Society.

Lower leg muscle involvement in Duchenne muscular dystrophy: an MR imaging and spectroscopy study

International Nuclear Information System (INIS)

Torriani, Martin; Townsend, Elise; Thomas, Bijoy J.; Bredella, Miriam A.; Ghomi, Reza H.; Tseng, Brian S.

2012-01-01

To describe the involvement of lower leg muscles in boys with Duchenne muscular dystrophy (DMD) by using MR imaging (MRI) and spectroscopy (MRS) correlated to indices of functional status. Nine boys with DMD (mean age, 11 years) and eight healthy age- and BMI-matched boys (mean age, 13 years) prospectively underwent lower leg MRI, 1H-MRS of tibialis anterior (TA) and soleus (SOL) for lipid fraction measures, and 31P-MRS for pH and high-energy phosphate measures. DMD subjects were evaluated using the Vignos lower extremity functional rating, and tests including 6 min walk test (6MWT) and 10 m walk. DMD subjects had highest fatty infiltration scores in peroneal muscles, followed by medial gastrocnemius and soleus. Compared to controls, DMD boys showed higher intramuscular fat (P = 0.04), lipid fractions of TA and SOL (P = 0.02 and 0.003, respectively), pH of anterior compartment (P = 0.0003), and lower phosphocreatine/inorganic phosphorus ratio of posterior compartment (P = 0.02). The Vignos rating correlated with TA (r = 0.79, P = 0.01) and SOL (r = 0.71, P = 0.03) lipid fractions. The 6MWT correlated with fatty infiltration scores of SOL (r = -0.76, P = 0.046), medial (r = -0.80, P = 0.03) and lateral (r = -0.84, P = 0.02) gastrocnemius, intramuscular fat (r = -0.80, P = 0.03), and SOL lipid fraction (r = -0.89, P = 0.007). Time to walk 10 m correlated with anterior compartment pH (r = 0.78, P = 0.04). Lower leg muscles of boys with DMD show a distinct involvement pattern and increased adiposity that correlates with functional status. Lower leg MRI and 1H-MRS studies may help to noninvasively demonstrate the severity of muscle involvement. (orig.)

Lower leg muscle involvement in Duchenne muscular dystrophy: an MR imaging and spectroscopy study

Energy Technology Data Exchange (ETDEWEB)

Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Massachusetts General Hospital, Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Townsend, Elise [MGH Institute of Health Professions and Massachusetts General Hospital, Boston, MA (United States); Thomas, Bijoy J.; Bredella, Miriam A.; Ghomi, Reza H. [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Tseng, Brian S. [Massachusetts General Hospital and Harvard Medical School, Pediatric Neuromuscular Clinic, Boston, MA (United States); Novartis Institute of Biomedical Research, Cambridge, MA (United States)

2012-04-15

To describe the involvement of lower leg muscles in boys with Duchenne muscular dystrophy (DMD) by using MR imaging (MRI) and spectroscopy (MRS) correlated to indices of functional status. Nine boys with DMD (mean age, 11 years) and eight healthy age- and BMI-matched boys (mean age, 13 years) prospectively underwent lower leg MRI, 1H-MRS of tibialis anterior (TA) and soleus (SOL) for lipid fraction measures, and 31P-MRS for pH and high-energy phosphate measures. DMD subjects were evaluated using the Vignos lower extremity functional rating, and tests including 6 min walk test (6MWT) and 10 m walk. DMD subjects had highest fatty infiltration scores in peroneal muscles, followed by medial gastrocnemius and soleus. Compared to controls, DMD boys showed higher intramuscular fat (P = 0.04), lipid fractions of TA and SOL (P = 0.02 and 0.003, respectively), pH of anterior compartment (P = 0.0003), and lower phosphocreatine/inorganic phosphorus ratio of posterior compartment (P = 0.02). The Vignos rating correlated with TA (r = 0.79, P = 0.01) and SOL (r = 0.71, P = 0.03) lipid fractions. The 6MWT correlated with fatty infiltration scores of SOL (r = -0.76, P = 0.046), medial (r = -0.80, P = 0.03) and lateral (r = -0.84, P = 0.02) gastrocnemius, intramuscular fat (r = -0.80, P = 0.03), and SOL lipid fraction (r = -0.89, P = 0.007). Time to walk 10 m correlated with anterior compartment pH (r = 0.78, P = 0.04). Lower leg muscles of boys with DMD show a distinct involvement pattern and increased adiposity that correlates with functional status. Lower leg MRI and 1H-MRS studies may help to noninvasively demonstrate the severity of muscle involvement. (orig.)

Locomotion training of legged robots using hybrid machine learning techniques

Science.gov (United States)

Simon, William E.; Doerschuk, Peggy I.; Zhang, Wen-Ran; Li, Andrew L.

1995-01-01

In this study artificial neural networks and fuzzy logic are used to control the jumping behavior of a three-link uniped robot. The biped locomotion control problem is an increment of the uniped locomotion control. Study of legged locomotion dynamics indicates that a hierarchical controller is required to control the behavior of a legged robot. A structured control strategy is suggested which includes navigator, motion planner, biped coordinator and uniped controllers. A three-link uniped robot simulation is developed to be used as the plant. Neurocontrollers were trained both online and offline. In the case of on-line training, a reinforcement learning technique was used to train the neurocontroller to make the robot jump to a specified height. After several hundred iterations of training, the plant output achieved an accuracy of 7.4%. However, when jump distance and body angular momentum were also included in the control objectives, training time became impractically long. In the case of off-line training, a three-layered backpropagation (BP) network was first used with three inputs, three outputs and 15 to 40 hidden nodes. Pre-generated data were presented to the network with a learning rate as low as 0.003 in order to reach convergence. The low learning rate required for convergence resulted in a very slow training process which took weeks to learn 460 examples. After training, performance of the neurocontroller was rather poor. Consequently, the BP network was replaced by a Cerebeller Model Articulation Controller (CMAC) network. Subsequent experiments described in this document show that the CMAC network is more suitable to the solution of uniped locomotion control problems in terms of both learning efficiency and performance. A new approach is introduced in this report, viz., a self-organizing multiagent cerebeller model for fuzzy-neural control of uniped locomotion is suggested to improve training efficiency. This is currently being evaluated for a possible

Cardiovascular comorbidity in patients with restless legs syndrome: current perspectives

Directory of Open Access Journals (Sweden)

Vargas-Pérez NJ

2017-05-01

Full Text Available Noel J Vargas-Pérez, Kanika Bagai, Arthur S Walters Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA Introduction: Restless legs syndrome (RLS is a sensorimotor neurological disorder associated with poor quality of life. Growing evidence links RLS and periodic limb movement in sleep (PLMS with increased risk of cardiovascular and cerebrovascular disease. This article reviews the association of RLS and PLMS with cardiovascular disease (CVD. Methods: PubMed and Medline database (1990 to July 2016 were searched for the terms “restless legs,” “restless legs syndrome,” “periodic limb movements,” “periodic limb movements in sleep” cross-referenced with “cardiovascular disease,” “heart disease,” “coronary artery disease,” “coronary heart disease,” “heart arrhythmia,” “heart failure,” “congestive heart failure,” “echocardiogram,” “echocardiographic,” “hypertension,” “high blood pressure,” “cerebrovascular disease,” “stroke,” “autonomic nervous system,” “heart rate,” “heart rate variability,” “hypoxia,” “microcirculation,” “oxidative stress,” “inflammation,” “chronic kidney disease,” “end-stage renal disease,” “renal disease,” “hemodialysis,” “multiple sclerosis,” “Parkinson,” “Parkinson’s,” “iron deficiency anemia,” and “mortality.” Other relevant articles from the reference list of the above-matched manuscripts were also reviewed. Studies that did not specify the diagnostic criteria for RLS or manuscripts in languages other than English were excluded. Articles with emphasis in RLS secondary to pregnancy were not included in this manuscript.Results: Eighty-six original articles were included in this review. Although mixed results were found regarding the association of RLS and PLMS with CVD, hypertension, stroke and mortality, an informal review of the literature does suggest that the

Distance Between the Malleoli and the GroundA New Clinical Method to Measure Leg-Length Discrepancy.

Science.gov (United States)

Aguilar, Estela Gomez; Domínguez, Águeda Gómez; Peña-Algaba, Carolina; Castillo-López, José M

2017-03-01

The aim of this work is to introduce a useful method for the clinical diagnosis of leg-length inequality: distance between the malleoli and the ground (DMG). A transversal observational study was performed on 17 patients with leg-length discrepancy. Leg-length inequality was determined with different clinical methods: with a tape measure in a supine position from the anterior superior iliac spine (ASIS) to the internal and external malleoli, as the difference between the iliac crests when standing (pelvimeter), and as asymmetry between ASISs (PALpation Meter [PALM]; A&D Medical Products Healthcare, San Jose, California). The Foot Posture Index (FPI) and the navicular drop test were also used. The DMG with Perthes rule (perpendicular to the foot when standing), the distance between the internal malleolus and the ground (DIMG), and the distance between the external malleolus and the ground were designed by the authors. The DIMG is directly related to the traditional ASIS-external malleolus measurement (P = .003), the FPI (P = .010), and the navicular drop test (P DMG) is useful for diagnosing leg-length discrepancy and is related to the ASIS-external malleolus measurement. The DIMG is significantly inversely proportional to the degree of pronation according to the FPI. Conversely, determination of leg-length discrepancy with a tape measure from the ASIS to the malleoli cannot be performed interchangeably at the level of the internal or external malleolus.

Working memory load modulates microsaccadic rate.

Science.gov (United States)

Dalmaso, Mario; Castelli, Luigi; Scatturin, Pietro; Galfano, Giovanni

2017-03-01

Microsaccades are tiny eye movements that individuals perform unconsciously during fixation. Despite that the nature and the functions of microsaccades are still lively debated, recent evidence has shown an association between these micro eye movements and higher order cognitive processes. Here, in two experiments, we specifically focused on working memory and addressed whether differential memory load could be reflected in a modulation of microsaccade dynamics. In Experiment 1, participants memorized a numerical sequence composed of either two (low-load condition) or five digits (high-load condition), appearing at fixation. The results showed a reduction in the microsaccadic rate in the high-load compared to the low-load condition. In Experiment 2, five red or green digits were always presented at fixation. Participants either memorized the color (low-load condition) or the five digits (high-load condition). Hence, visual stimuli were exactly the same in both conditions. Consistent with Experiment 1, microsaccadic rate was lower in the high-load than in the low-load condition. Overall, these findings reveal that an engagement of working memory can have an impact on microsaccadic rate, consistent with the view that microsaccade generation is pervious to top-down processes.

On the Necessity of Including Joint Passive Dynamics in the Impedance Control of Robotic Legs

Directory of Open Access Journals (Sweden)

Juan Carlos Arevalo

2014-07-01

Full Text Available Bioinspired quadruped robots are among the best robot designs for field missions over the complex terrain encountered in extraterrestrial landscapes and disaster scenarios caused by natural and human-made catastrophes, such as those caused by nuclear power plant accidents and radiological emergencies. For such applications, the performance characteristics of the robots should include high mobility, adaptability to the terrain, the ability to handle a large payload and good endurance. Nature can provide inspiration for quadruped designs that are well suited for traversing complex terrain. Horse legs are an example of a structure that has evolved to exhibit good performance characteristics. In this paper, a leg design exhibiting the key features of horse legs is briefly described. This leg is an underactuated mechanism because it has two actively driven degrees of freedom (DOFs and one passively driven DOF. In this work, two control laws intended to be use in the stan ce phase are described: a control law that considers passive mechanism dynamics and a second law that neglects these dynamics. The performance of the two control laws is experimentally evaluated and compared. The results indicate that the first control law better achieves the control goal; however, the use of the second is not completely unjustified.

[Physical treatment modalities for chronic leg ulcers].

Science.gov (United States)

Dissemond, J

2010-05-01

An increasing numbers of physical treatment options are available for chronic leg ulcer. In this review article, compression therapy, therapeutic ultrasound, negative pressure therapy, extracorporeal shock wave therapy, electrostimulation therapy, electromagnetic therapy, photodynamic therapy, water-filtered infrared-A-radiation and hydrotherapy are discussed in terms of their practical applications and the underlying evidence. With the exception of compression therapy for most of these treatments, good scientific data are not available. However this is a widespread problem in the treatment of chronic wounds. Nevertheless, several of the described methods such as negative pressure therapy represent one of the gold standards in practical treatment of patients with chronic leg ulcers. Although the use of physical treatment modalities may improve healing in patients with chronic leg ulcers, the diagnosis and treatment of the underlying causes are essential for long-lasting success.

Using near infrared light to manage symptoms associated with restless legs syndrome.

Science.gov (United States)

Guffey, J Stephen; Motts, Susan; Barymon, Deanna; Wooten, Amber; Clough, Tim; Payne, Emily; Henderson, McCall; Tice, Neal

2016-01-01

The purpose of this study was to determine whether the application of near infrared (NIR) light could positively modulate symptoms associated with restless legs syndrome (RLS). Twenty-one subjects with RLS were treated with NIR three times weekly for four weeks. Baseline measures of: (1) international restless legs syndrome rating scale (IRLSRS) score; (2) Semmes Weinstein monofilament (SWM) test; (3) visual analog pain scale (VAS); (4) ankle-brachial index (ABI); and (5) sonographic imaging of the popliteal and posterior tibial arteries were compared to post-treatment values. NIR (850 nm) was delivered transcutaneously at 8 J/cm(2) to four locations on each leg and the plantar surface of each foot. A pre-test-post-test one group design was employed. Baseline and post-treatment measures were compared using either a dependent t-test when data were normal or the Wilcoxon signed rank test in the absence of normality. A significant improvement in IRLSRS scores was observed. Sensation improved from less than protective in 16.6% of sites tested at the baseline to 13.4% post-intervention. There was a significant improvement in ABI scores. VAS and sonographic imaging measures other than ABI remained unchanged. The use of NIR to modulate symptoms associated with RLS was supported by the data.

Sleep board review question: restless legs

Directory of Open Access Journals (Sweden)

Omobomi O

2018-02-01

Full Text Available No abstract available. Article truncated after 150 words. Ms. Jones (not her real name is a 63-year-old woman who states that she gets very fidgety when sitting in a theater, watching a movie or when flying long distances on a plane. She is unable to find words to describe the sensation but she states that moving her legs make them feel better. Lately, she has been getting this feeling almost every night. She reports no leg discomfort in the daytime. She denies muscle cramps her legs. She had some recent investigations done by her primary care physician because of complaints of fatigue. Which of the following will be helpful in the diagnosis and management in this patient? 1. An overnight polysomnogram showing apnea hypopnea index of 1.6 events per hour and no periodic limb movements (PLMs 2. Ferritin level of 18 ng/ml (normal range 20-200 ng/ml 3. Serum Bicarbonate of 29 mEq/L (normal range 23-29 mEq/L 4. Thyroid …

Topological phases in frustrated synthetic ladders with an odd number of legs

Science.gov (United States)

Barbarino, Simone; Dalmonte, Marcello; Fazio, Rosario; Santoro, Giuseppe E.

2018-01-01

The realization of the Hofstadter model in a strongly anisotropic ladder geometry has now become possible in one-dimensional optical lattices with a synthetic dimension. In this work, we show how the Hofstadter Hamiltonian in such ladder configurations hosts a topological phase of matter which is radically different from its two-dimensional counterpart. This topological phase stems directly from the hybrid nature of the ladder geometry and is protected by a properly defined inversion symmetry. We start our analysis by considering the paradigmatic case of a three-leg ladder which supports a topological phase exhibiting the typical features of topological states in one dimension: robust fermionic edge modes, a degenerate entanglement spectrum, and a nonzero Zak phase; then, we generalize our findings—addressable in the state-of-the-art cold-atom experiments—to ladders with a higher number of legs.

Can Wound Exudate from Venous Leg Ulcers Measure Wound Pain Status?: A Pilot Study.

Directory of Open Access Journals (Sweden)

Taichi Goto

Full Text Available We investigated the associations between the self-evaluated pain status and two pain biomarker candidates, nerve growth factor and S100A8/A9, in exudate from venous leg ulcer to finally develop an objective pain evaluation method. Patients with venous leg ulcer participated in this cross-sectional observational study conducted between April and October 2014 at two medical facilities. During routine wound care, each participant self-evaluated their pain status at each examination using the 10-point numerical rating scale (present pain intensity and the short-form McGill Pain Questionnaire 2 (continuous pain, intermittent pain, neuropathic pain, affective descriptors, and total score. Venous leg ulcer exudate sample was collected after wound cleansing. The nerve growth factor and S100A8/A9 concentrations in the venous leg ulcer exudate were measured by enzyme-linked immunosorbent assay and standardized according to the wound area. The association between each pain status and the two standardized protein concentrations was evaluated using Spearman's correlation coefficient. In 30 sample collected from 13 participants, the standardized nerve growth factor concentration was negatively correlated with continuous pain (ρ = -0.47, P = 0.01, intermittent pain (ρ = -0.48, P = 0.01, neuropathic pain (ρ = -0.51, P = 0.01, and total score (ρ = -0.46, P = 0.01. The standardized S100A8/A9 concentration was positively correlated with present pain intensity (ρ = 0.46, P = 0.03 and continuous pain (ρ = 0.48, P = 0.03. Thus, these two proteins may be useful for objective evaluation of wound pain in venous leg ulcer patients.

How do marital status, work effort, and wage rates interact?

Science.gov (United States)

Ahituv, Avner; Lerman, Robert I

2007-08-01

How marital status interacts with men's earnings is an important analytic and policy issue, especially in the context of debates in the United States over programs that encourage healthy marriage. This paper generates new findings about the earnings-marriage relationship by estimating the linkages among flows into and out of marriage, work effort, and wage rates. The estimates are based on National Longitudinal Survey of Youth panel data, covering 23 years of marital and labor market outcomes, and control for unobserved heterogeneity. We estimate marriage effects on hours worked (our proxy for work effort) and on wage rates for all men and for black and low-skilled men separately. The estimates reveal that entering marriage raises hours worked quickly and substantially but that marriage's effect on wage rates takes place more slowly while men continue in marriage. Together; the stimulus to hours worked and wage rates generates an 18%-19% increase in earnings, with about one-third to one-half of the marriage earnings premium attributable to higher work effort. At the same time, higher wage rates and hours worked encourage men to marry and to stay married. Thus, being married and having high earnings reinforce each other over time.

Restless Legs Syndrome in shift workers: A cross sectional study on male assembly workers

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Rahimi Mohsen

2009-09-01

Full Text Available Abstract Background Restless Legs Syndrome (RLS is a common neurological movement disorder characterized by symptoms that follow a circadian pattern. Night and rotating shift work schedules exert adverse effects on functions of the human body by disturbing circadian rhythms, and they are known to cause sleep disturbances and insomnia. In this paper, we investigate the possible association between shift work and RLS. Methods This cross sectional study was conducted in an automobile manufacturing factory in Tehran, Iran. A total of 780 male assembly workers were recruited in three groups, each with 260 workers: workers on a permanent morning shift (A and two different rotating shift schedules (B and C with morning, afternoon and night shifts. We used the international RLS study group criteria for diagnosis of RLS, and the severity scale for severity assessment in subjects with RLS. Self administered questionnaires were used to gather information on age, smoking, work history, medical condition, and existence and severity of RLS symptoms. Results The prevalence of RLS was significantly higher in rotational shift workers (15% than workers with permanent morning work schedule (8.5%. In workers suffering from RLS, we found greater mean values of age and work experience, higher percentages of drug consumption, smoking, and co-morbid illnesses compared with subjects who did not have RLS, although these differences were statistically significant only for age, work experience and drug consumption. Conclusion Rotational shift work acts as a risk or exacerbating factor for Restless Legs Syndrome.

Restless Legs Syndrome in shift workers: A cross sectional study on male assembly workers.

Science.gov (United States)

Sharifian, Akbar; Firoozeh, Marjan; Pouryaghoub, Gholamreza; Shahryari, Mehran; Rahimi, Mohsen; Hesamian, Mohammad; Fardi, Ali

2009-09-14

Restless Legs Syndrome (RLS) is a common neurological movement disorder characterized by symptoms that follow a circadian pattern. Night and rotating shift work schedules exert adverse effects on functions of the human body by disturbing circadian rhythms, and they are known to cause sleep disturbances and insomnia. In this paper, we investigate the possible association between shift work and RLS. This cross sectional study was conducted in an automobile manufacturing factory in Tehran, Iran. A total of 780 male assembly workers were recruited in three groups, each with 260 workers: workers on a permanent morning shift (A) and two different rotating shift schedules (B and C) with morning, afternoon and night shifts. We used the international RLS study group criteria for diagnosis of RLS, and the severity scale for severity assessment in subjects with RLS. Self administered questionnaires were used to gather information on age, smoking, work history, medical condition, and existence and severity of RLS symptoms. The prevalence of RLS was significantly higher in rotational shift workers (15%) than workers with permanent morning work schedule (8.5%). In workers suffering from RLS, we found greater mean values of age and work experience, higher percentages of drug consumption, smoking, and co-morbid illnesses compared with subjects who did not have RLS, although these differences were statistically significant only for age, work experience and drug consumption. Rotational shift work acts as a risk or exacerbating factor for Restless Legs Syndrome.

Duplex sonography of the near-surface leg veins; Duplexsonographie der oberflaechlichen Beinvenen

Energy Technology Data Exchange (ETDEWEB)

Mendoza, E.

2007-07-01

The book contains the following contributions: The ultrasonograph, selection of the ultrasonic transducer, anatomy of the near-surface vein system, physiology of the near-surface vein system, varicose status classification, systematics of the duplex sonography of near-surface leg veins, provocational maneuver for the duplex sonographic varicose diagnostics, exploration of vena saphena parva, perforans veins, side branches, phlebitis, sonography for varicose therapy, postsurgical sonography, deep leg veins, examination of near-surface leg veins for the pathology of the deep vein system, differential diagnostic clarification of leg oedema from the phlebologic-lymphological view, diagnostic side features along the near-surface leg veins.

UPTF-TRAM test A2. Formation of stratified flow in the hot leg

International Nuclear Information System (INIS)

Tenckhoff; Brand, B.; Weiss, P.

1992-10-01

The separate effect UPTF TRAM Test A2 consisting of six runs was designed to investigate flow regimes in the hot leg of a pressurized water reactor under two-phase natural circulation conditions. In particular, the following phenomena were investigated: - Formation of different flow regimes, e.g. stratified and slug flow in the hot leg under different boundary conditions; -Correlation between flow regime and boundary conditions of the system (mass flows, water level etc.); - Mechanism of the transport of water into the steam generator. The test runs are divided into two groups: a) Test Runs 01a, 01b and 02b with steam injection through the core simulator: In these test runs the steam injection through the core simulator was increased stepwise. In each step the steam injection was kept constant for about 100 s in order to observe steady water distribution in the hot leg and SG-simulator of broken loop. b) Test Runs 03c, 04c and 04d with steam and water injection through the core simulator: These test runs were performed at a constant steam injection rate and the water injection rate was increased stepwise. In order to verify the consistency of scaling with the pressure, the test runs were carried out at different pressures as: a) Runs 01a and 01b at 15 bar, and Run 02b at 3 bar b) Runs 03c, 04c and 04d at 15, 3 and 5 bar respectively. A preliminary evaluation of the test is presented in the Quick Look Report. (orig.) [de

PELATIHAN PLIOMETRIK ALTERNATE LEG BOUND DAN DOUBLE LEG BOUND MENINGKATKAN DAYA LEDAK OTOT TUNGKAI PADA SISWA PUTRA KELAS VII SMP NEGERI 3 SUKAWATI TAHUN PELAJARAN 2012/2013

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Komang Ayu Tri Widhiyanti

2013-11-01

Full Text Available This study was conducted to know the improvement the explosive power of leg muscle. It was done through 5 set 12 repetitions during 6 weeks in the field of SMP Negeri 3 Sukawati started from 4 p.m. until 6 p.m. There were 3 groups applied in this study such as group 1 (control group that was instructed to kick a ball, group 2 (plyometric training of alternate leg bound, and group 3 (plyometric training of double leg bound. The sample was 14 male students who were in the seventh grade class of SMP Negeri 3 Sukawati in the academic year 2012/2013. The data was gained by doing the movement of alternate leg bound and double leg bound that each movement was done three times before and after the training. The hypothesis was examined by using independent t-test with the result 0.05 (p<0.05. Based on the different result of analysis test in each group, the gain score of the group 2 with the group 1 about 0,51 that shows the significant differences p = 0,00, the gain score of the group 2 with the group 3 about 0,31 that shows the significant differences p = 0,00, the gain score of the group 3 with the group 1 about 0,20 that shows the significant differences p = 0,00. Thus, alternate leg bound plyometric training is more effective than double leg bound. It is expected that the coach and the gym teacher to apply alternate leg bound plyometric training as an alternative to improve the explosive power of leg muscle.

Leg kinematics and kinetics in landing from a single-leg hop for distance. A comparison between dominant and non-dominant leg

NARCIS (Netherlands)

van der Harst, J. J.; Gokeler, A.; Hof, A. L.

Background. Anterior cruciate ligament (ACL) deficiency can be a major problem for athletes and subsequent reconstruction of the ACL may be indicated if a conservative regimen has failed. After ACL reconstruction signs of abnormality in the use of the leg remain for a long time. It is expected that

Roll type conducting polymer legs for rigid-flexible thermoelectric generator

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Teahoon Park

2017-07-01

Full Text Available A roll-type conducting polymer film was explored as a flexible organic p-type thermoelectric leg using poly(3,4-ethylenedioxythiophene (PEDOT doped with tosylate. The PEDOT films were prepared through solution casting polymerization and rolled up for a roll-type leg. Due to the high flexibility, the roll-type PEDOT leg enabled easy contact to both top and bottom electrodes. Simulation on the dynamic heat transfer and convective cooling for a vertically roosted rod- and roll-type PEDOT leg showed that the temperature difference (ΔT between the hot and cold sides of the leg was much higher in the roll than that of the rod. The PEDOT legs were integrated with n-type Bi2Te3 blocks, to give a 36-couple rigid-flexible thermoelectric generator (RF-TEG. The maximum output voltage from the 36-couple RF-TEG under a ΔT of 7.9 K was determined as 36.7 mV along with a high output power of 115 nW. A wearable RF-TEG was prepared upon the combination of the 36-couple RF-TEG with an arm warmer, to afford an output voltage of 10.6 mV, which was generated constantly and steadily from human wrist heat.

The prefrontal oxygenation and ventilatory responses at start of one-legged cycling exercise have relation to central command.

Science.gov (United States)

Asahara, Ryota; Matsukawa, Kanji; Ishii, Kei; Liang, Nan; Endo, Kana

2016-11-01

When performing exercise arbitrarily, activation of central command should start before the onset of exercise, but when exercise is forced to start with cue, activation of central command should be delayed. We examined whether the in-advance activation of central command influenced the ventilatory response and reflected in the prefrontal oxygenation, by comparing the responses during exercise with arbitrary and cued start. The breath-by-breath respiratory variables and the prefrontal oxygenated-hemoglobin concentration (Oxy-Hb) were measured during one-legged cycling. Minute ventilation (V̇e) at the onset of arbitrary one-legged cycling was augmented to a greater extent than cued cycling, while end-tidal carbon dioxide tension (ETco 2 ) decreased irrespective of arbitrary or cued start. Symmetric increase in the bilateral prefrontal Oxy-Hb occurred before and at the onset of arbitrary one-legged cycling, whereas such an increase was absent with cued start. The time course and magnitude of the increased prefrontal oxygenation were not influenced by the extent of subjective rating of perceived exertion and were the same as those of the prefrontal oxygenation during two-legged cycling previously reported. Mental imagery or passive performance of the one-legged cycling increased V̇e and decreased ETco 2 Neither intervention, however, augmented the prefrontal Oxy-Hb. The changes in ETco 2 could not explain the prefrontal oxygenation response during voluntary or passive one-legged cycling. Taken together, it is likely that the in-advance activation of central command influenced the ventilatory response by enhancing minute ventilation at the onset of one-legged cycling exercise and reflected in the preexercise increase in the prefrontal oxygenation. Copyright © 2016 the American Physiological Society.

Prosthetic Leg Control in the Nullspace of Human Interaction.

Science.gov (United States)

Gregg, Robert D; Martin, Anne E

2016-07-01

Recent work has extended the control method of virtual constraints, originally developed for autonomous walking robots, to powered prosthetic legs for lower-limb amputees. Virtual constraints define desired joint patterns as functions of a mechanical phasing variable, which are typically enforced by torque control laws that linearize the output dynamics associated with the virtual constraints. However, the output dynamics of a powered prosthetic leg generally depend on the human interaction forces, which must be measured and canceled by the feedback linearizing control law. This feedback requires expensive multi-axis load cells, and actively canceling the interaction forces may minimize the human's influence over the prosthesis. To address these limitations, this paper proposes a method for projecting virtual constraints into the nullspace of the human interaction terms in the output dynamics. The projected virtual constraints naturally render the output dynamics invariant with respect to the human interaction forces, which instead enter into the internal dynamics of the partially linearized prosthetic system. This method is illustrated with simulations of a transfemoral amputee model walking with a powered knee-ankle prosthesis that is controlled via virtual constraints with and without the proposed projection.

Hereditary Lymphedema of the Leg – A Case Report

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Birgit Heinig

2017-07-01

Full Text Available Primary of hereditary lymphedema is a rare but progressive disease. It is yet not curable. We present a 48-year-old male patient with hereditary lymphedema of his left leg, that was realised by minor trauma (able twist when he was seven years old. He had never been treated for lymphedema but experienced multiple erysipelas during his life. After diagnostic procedures to exclude other causes of leg swelling, the diagnosis of hereditary lymphedema of the leg, stage III was confirmed. We initialized complex decongestive therapy. During two weeks of intensive treatment, the circumference of the left leg could be reduced by 10 cm. This case illustrates the "natural course" hereditary lymphedema. But it raises the hope that even after decades of ignorance, the patients benefits from complex decongestive treatment. Therapeutic nihilism is unnecessary and poses lymphedema patients to risks of infection and secondary malignancies like Stewart-Trewes syndrome.

Development of PIMAL: Mathematical Phantom with Moving Arms and Legs

Energy Technology Data Exchange (ETDEWEB)

Akkurt, Hatice [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eckerman, Keith F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2007-05-01

The computational model of the human anatomy (phantom) has gone through many revisions since its initial development in the 1970s. The computational phantom model currently used by the Nuclear Regulatory Commission (NRC) is based on a model published in 1974. Hence, the phantom model used by the NRC staff was missing some organs (e.g., neck, esophagus) and tissues. Further, locations of some organs were inappropriate (e.g., thyroid).Moreover, all the computational phantoms were assumed to be in the vertical-upright position. However, many occupational radiation exposures occur with the worker in other positions. In the first phase of this work, updates on the computational phantom models were reviewed and a revised phantom model, which includes the updates for the relevant organs and compositions, was identified. This revised model was adopted as the starting point for this development work, and hence a series of radiation transport computations, using the Monte Carlo code MCNP5, was performed. The computational results were compared against values reported by the International Commission on Radiation Protection (ICRP) in Publication 74. For some of the organs (e.g., thyroid), there were discrepancies between the computed values and the results reported in ICRP-74. The reasons behind these discrepancies have been investigated and are discussed in this report.Additionally, sensitivity computations were performed to determine the sensitivity of the organ doses for certain parameters, including composition and cross sections used in the simulations. To assess the dose for more realistic exposure configurations, the phantom model was revised to enable flexible positioning of the arms and legs. Furthermore, to reduce the user time for analyses, a graphical user interface (GUI) was developed. The GUI can be used to visualize the positioning of the arms and legs as desired posture is achieved to generate the input file, invoke the computations, and extract the organ dose

CALCANEAL MINERAL DENSITY IN CHILDREN ATHLETES AND TAKE-OFF LEG

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Borislav Obradović

2010-06-01

Full Text Available It is well-known that physical activity has an anabolic effect on the bone tissue. To examine the influence of the take-off lower limb to the bone density we studied a group of prepubertal boys and girls at the initial phase of their peak bone mass acquisition. A sample consisted of 60 subjects ie., 32 soccer players (boys, 10.7±0.5 years old and 28 swimmers (15 girls and 13 boys, 10.8±0.8 years old, who had performed at least one year of high-level sport training (10-15 hours per week for soccer players, 8-12 hours per week for swimmers. The sample was divided into two groups: the first consisted of 40 subjects, with the left take-off leg, while the second consisted of 20 subjects, with the right take-off leg. The bone mineral density (BMD measurements of the left and the right calcaneus were performed using ultrasound densitometer “Sahara” (Hologic, Inc., MA, USA. There were no significant differences between the groups in regard to BUA and SOS of both the left and the right take-off lower legs. Mean BUA of the take-off left leg and the take-off right leg were different, but not significantly (p>0.05. Likewise, mean SOS of the take-off left leg and the take-off right leg were different, but it was not significant (p>0.05. The results do not indicate that the take-off lower limb has an influence on calcaneal bone mineral density.

The second leg home advantage: evidence from European football cup competitions.

Science.gov (United States)

Page, Lionel; Page, Katie

2007-12-01

The home advantage is a widely acknowledged sporting phenomenon, especially in association football. Here, we examine the second leg home advantage, an effect that is discussed in the public domain but which has received very little scientific attention. The second leg home advantage effect occurs when on average teams are more likely to win a two-stage knock-out competition when they play at home in the second leg. That is, both teams have a home advantage but this advantage is significantly greater for the team that plays at home second. Examining data from three different European Cup football competitions spanning 51 years, we show that the second leg home advantage is a real phenomenon. The second leg home team has more than a 50% probability to qualify for the next round in the competition even after controlling for extra time and team ability as possible alternative explanations. The second leg home advantage appears, however, to have decreased significantly over the past decade. Possible reasons for its existence and subsequent decline are presented.

Differential glucose uptake in quadriceps and other leg muscles during one-legged dynamic submaximal knee-extension exercise

DEFF Research Database (Denmark)

Kalliokoski, Kari K; Boushel, Robert; Langberg, Henning

2011-01-01

One-legged dynamic knee-extension exercise (DKE) is a widely used model to study the local cardiovascular and metabolic responses to exercise of the quadriceps muscles. In this study, we explored the extent to which different muscles of the quadriceps are activated during exercise using positron...... emission tomography (PET) determined uptake of [18F]-fluoro-deoxy-glucose (GU) during DKE. Five healthy male subjects performed DKE at 25 W for 35 min and both the contracting and contralateral resting leg were scanned with PET from mid-thigh and distally. On average, exercise GU was the highest...

Work-related ill health in doctors working in Great Britain: incidence rates and trends.

Science.gov (United States)

Zhou, Anli Yue; Carder, Melanie; Gittins, Matthew; Agius, Raymond

2017-11-01

Background Doctors have a higher prevalence of mental ill health compared with other professional occupations but incidence rates are poorly studied. Aims To determine incidence rates and trends of work-related ill health (WRIH) and work-related mental ill health (WRMIH) in doctors compared with other professions in Great Britain. Method Incidence rates were calculated using an occupational physician reporting scheme from 2005-2010. Multilevel regression was use to study incidence rates from 2001 to 2014. Results Annual incidence rates for WRIH and WRIMH in doctors were 515 and 431 per 100 000 people employed, respectively. Higher incidence rates for WRIH and WRMIH were observed for ambulance staff and nurses, respectively. Doctors demonstrated an annual average incidence rates increase for WRIH and WRMIH, especially in women, whereas the other occupations demonstrated a decreasing or static trend. The difference in trends between the occupations was statistically significant. Conclusions WRIH and WRMIH incidence rate are increasing in doctors, especially in women, warranting further research. © The Royal College of Psychiatrists 2017.

The mangled lower leg

NARCIS (Netherlands)

Hoogendoorn, Jochem Maarten

2002-01-01

A surgeon faced with a patient presenting with an open tibial/fibular fracture in combination with severe damage of the surrounding soft tissues, has to make the difficult decision whether to attempt salvage or to perform an immediate amputation of the leg. Until late in the nineteenth century the

Locomotor-like leg movements evoked by rhythmic arm movements in humans.

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Francesca Sylos-Labini

Full Text Available Motion of the upper limbs is often coupled to that of the lower limbs in human bipedal locomotion. It is unclear, however, whether the functional coupling between upper and lower limbs is bi-directional, i.e. whether arm movements can affect the lumbosacral locomotor circuitry. Here we tested the effects of voluntary rhythmic arm movements on the lower limbs. Participants lay horizontally on their side with each leg suspended in an unloading exoskeleton. They moved their arms on an overhead treadmill as if they walked on their hands. Hand-walking in the antero-posterior direction resulted in significant locomotor-like movements of the legs in 58% of the participants. We further investigated quantitatively the responses in a subset of the responsive subjects. We found that the electromyographic (EMG activity of proximal leg muscles was modulated over each cycle with a timing similar to that of normal locomotion. The frequency of kinematic and EMG oscillations in the legs typically differed from that of arm oscillations. The effect of hand-walking was direction specific since medio-lateral arm movements did not evoke appreciably leg air-stepping. Using externally imposed trunk movements and biomechanical modelling, we ruled out that the leg movements associated with hand-walking were mainly due to the mechanical transmission of trunk oscillations. EMG activity in hamstring muscles associated with hand-walking often continued when the leg movements were transiently blocked by the experimenter or following the termination of arm movements. The present results reinforce the idea that there exists a functional neural coupling between arm and legs.

Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

DEFF Research Database (Denmark)

Truijen, J; Kim, Y S; Krediet, C T P

2012-01-01

posture, volume accumulation in small blood vessels contributes significantly to the total fluid volume accumulated in the legs. Considering that near-infrared spectroscopy (NIRS) tracks postural blood volume changes within the small blood vessels of the lower leg, we evaluated the NIRS-determined changes......-linear accumulation of blood volume in the small vessels of the leg, with an initial fast phase followed by a more gradual increase at least partly contributing to the relocation of fluid during orthostatic stress....

Low-Budget Instrumentation of a Conventional Leg Press to Measure Reliable Isometric-Strength Capacity.

Science.gov (United States)

Baur, Heiner; Groppa, Alessia Severina; Limacher, Regula; Radlinger, Lorenz

2016-02-02

Maximum strength and rate of force development (RFD) are 2 important strength characteristics for everyday tasks and athletic performance. Measurements of both parameters must be reliable. Expensive isokinetic devices with isometric modes are often used. The possibility of cost-effective measurements in a practical setting would facilitate quality control. The purpose of this study was to assess the reliability of measurements of maximum isometric strength (Fmax) and RFD on a conventional leg press. Sixteen subjects (23 ± 2 y, 1.68 ± 0.05 m, 59 ± 5 kg) were tested twice within 1 session. After warm-up, subjects performed 2 times 5 trials eliciting maximum voluntary isometric contractions on an instrumented leg press (1- and 2-legged randomized). Fmax (N) and RFD (N/s) were extracted from force-time curves. Reliability was determined for Fmax and RFD by calculating the intraclass correlation coefficient (ICC), the test-retest variability (TRV), and the bias and limits of agreement. Reliability measures revealed good to excellent ICCs of .80-.93. TRV showed mean differences between measurement sessions of 0.4-6.9%. The systematic error was low compared with the absolute mean values (Fmax 5-6%, RFD 1-4%). The implementation of a force transducer into a conventional leg press provides a viable procedure to assess Fmax and RFD. Both performance parameters can be assessed with good to excellent reliability allowing quality control of interventions.

Eyelash Transplantation Using Leg Hair by Follicular Unit Extraction

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Sanusi Umar, MD

2015-03-01

Full Text Available Summary: Fine hairs of the head and nape areas have been used as donor sources in eyelash transplantation but are straight, coarse, and grow rapidly, requiring frequent eyelash maintenance. This is the first reported case of eyelash transplantation by follicular unit extraction using leg hair as a donor source; findings were compared with that of another patient who underwent a similar procedure with donor hairs from the nape area. Although both patients reported marked improvement in fullness of eyelashes within 3 months postsurgery, the transplanted leg hair eyelashes required less frequent trimming (every 5–6 weeks compared with nape hair eyelashes (every 2–3 weeks. Additionally, in leg hair eyelashes, the need for perming to sustain a natural looking eyelash curl was eliminated. Eyelash transplantation using leg donor hair in hirsute women may result in good cosmetic outcomes and require less maintenance compared with nape donor hair.

Effect of Adding the White Legged Shrimp (Penaeus vannamei on Growth and Survival of Tiger Shrimp (Penaeus monodon in Intensive Farming

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. Tarsim

2007-12-01

Full Text Available This experiment was carried out in the framework of a project to develop a viable shrimp polyculture technology under intensive farming. The objectives were to assess the effect of adding white legged shrimp (Penaeus vannamei on growth and survival of tiger shrimp (Penaeus monodon in intensive Farming. Tiger shrimp were stocked in 2800-3400 m2 earthen ponds at 40 individuals/m2 and reared for 133 days. White legged shrimp added at 70 day at 8±2 individuals/m2. Growth rate and total yield affected by addition of this species. Final  affected by white legged shrimp addition. No adding effects were found on the water quality parameters. The results indicate that, at densities tested, white legged shrimp addition to the intensive farming of tiger shrimp polyculture is viable as species increase crop production Key words: Penaeus vannamei, P. monodon, growth, survival, polyculture

Screening three Finfish Species for their Potential in Removing Organic Matter from the Effluent of White Leg Shrimps (Litopenaeus vannamei Farming

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Nguyen, LQ.

2016-01-01

Full Text Available White leg shrimp (Litopenaeus vannamei farming effluent contains pollutants that include high levels of organic matter (OM nutrients and growth-promoting substances. This study investigated the effects of varied concentrations of white leg shrimp (Litopenaeus vannamei farm wastewater 0, 50, 75 and 100%, on the survival rate (SR of three finfish species: tilapia (Oreochromis niloticus, grey mullet (Mugil cephalus and rabbit fish (Siganus guttatus as part of screening their potential in removing organic matter from the effluent of white leg shrimp farming. The different initial levels of shrimp wastewater from 50% to 100% had no significant effect on the survival rate of tilapia and mullet; but the survival rate of S. guttatus significantly decreased with increasing shrimp wastewater (P<0.05. The results showed that the removal of BOD, COD and TSS occurred in the range of 66-83, 68-81 and 30-54%; respectively and the removal efficiency of OM by mullet was higher than Tilapia in all treatments. The study also indicated that the reduction highest removal of BOD, COD and TSS was achieved being 83.1%, 80.7and 53,7% respectively, at the medium stocking density (25 fish/m2 of mullet.

Sleep apnea in patients reporting insomnia or restless legs symptoms.

Science.gov (United States)

Bianchi, M T; Goparaju, B; Moro, M

2016-01-01

Insomnia and restless legs syndrome (RLS) are defined by self-reported symptoms, and polysomnography (PSG) is not routinely indicated. Occult obstructive sleep apnea (OSA), common even in asymptomatic adults, may complicate management of patients presenting with insomnia or restless legs. To this end, we investigated objective sleep apnea metrics in a large retrospective cohort according to self-reported symptom profiles. We compared sleep apnea findings in patients referred to our center according to self-reported symptoms associated with insomnia, sleep apnea, and restless legs. The cohort included over 1900 adults who underwent diagnostic (n = 1418) or split-night (n = 504) PSGs and completed a symptom and medical history questionnaire. More than 30% of patients who did not endorse any OSA symptoms, but did endorse insomnia or restless legs symptoms, were found to have OSA based on apnea-hypopnea index (AHI) >5 during overnight laboratory testing. Regression models of the full cohort showed that the risk of OSA was related, as expected, to older age, male sex, elevated body mass index, and presence of OSA symptoms. The presence of insomnia symptoms did not alter the risk of OSA. The presence of restless legs symptoms showed a small odds ratio for lowered OSA risk. Objective evidence of OSA occurs similarly in those with insomnia or restless legs symptoms, even among those without self-reported OSA symptoms. Providers should be aware of the potential for occult OSA in populations with insomnia and restless legs, which may complicate their management in addition to presenting an independent medical risk itself. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessment of nutritional status in adult patients with cystic fibrosis: whole-body bioimpedance vs body mass index, skinfolds, and leg-to-leg bioimpedance

NARCIS (Netherlands)

Hollander, F.M.; Roos, de N.M.; Vries, de J.H.M.; Berkhout, van F.T.

2005-01-01

Objective: To investigate whether body mass index (BMI) or body fat percentage estimated from BMI, skinfolds, or leg-to-leg bioimpedance are good indicators of nutritional status in adult patients with cystic fibrosis. Body fat percentage measured by whole-body bioimpedance was used as the reference

Sensitivity of sensor-based sit-to-stand peak power to the effects of training leg strength, leg power and balance in older adults

NARCIS (Netherlands)

Regterschot, G Ruben H; Folkersma, Marjanne; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS

The Influence of Bi Rate to the Distribution of Working Capital Loans

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Dian Kurnianingrum

2015-11-01

Full Text Available This research “The influence of BI rate to the distribution of working capital loans" is conducted at Indonesian commercial bank during the month of January 2005 until May 2009. The purpose of this research is to determine the effect of BI rate toward the distribution of working capital loans. To test the research hypotheses, the data were analyzed by using Pearson correlate and simple linear regression. Based on research, BI rate significantly influence the distribution of working capital loans. BI rate gives a negative impact to the distribution of working capital loans. It means, the increase in BI rate will decrease the distribution of working capital loans, and vice versa, the decrease in BI rate will increase the distribution of working capital loans.

BETHSY ISP-38 flow behaviour in hot leg

International Nuclear Information System (INIS)

Petelin, S.; Jurkovic, M.

1998-01-01

Betsy Test 6.9c OECD ISP-38 RELAP5/MOD3.2 input model was developed and simulation performed for loss of RHR system during mid-loop operation. Initial liquid level in RCS was at horizontal axis of the hot legs. Pressurizer and steam generator manways were opened 1 s after the transient was initiated. Secondary side is full of air and isolated. Results of calculations were satisfied except in surge line and in pressurizer where larger amount of water is presented. Liquid was entrained in that part of the system during bubbly or varies stratified flow in the hot leg. Due to non-physical results in hot leg pipe with connected surge line and pressurizer, RELAP5 horizontal stratification model deficiencies was studied and possible improvements investigated.(author)

[Fractures of the lower leg in professional skiers].

Science.gov (United States)

Mückley, T; Kruis, C; Schütz, T; Brucker, P; Bühren, V

2004-03-01

Fractures of the lower leg due to skiing accidents remain an important concern. Few studies have focussed on the special demands of professional athletes who sustain these injuries. We present our experience with three cases of lower leg fractures in competitive professional downhill skiers and discuss management and treatment concepts. We performed limited reamed compression nailing in all the patients presented because it offers the advantages of high mechanical stability and optimized fragment apposition. Plate osteosynthesis of the fibula is not required in most typical fractures. All patients resumed ski training. Two of them returned to World Cup. Only one achieved her pre-injury World Cup level of performance and success. In conclusion, a successful return for professional skiers with lower leg fractures is feasible using an optimized treatment strategy.

Laboratory on Legs: An Architecture for Adjustable Morphology with Legged Robots

Science.gov (United States)

2012-04-01

including walking, running,7 pronking,8,9 leaping and flipping,10 climbing stairs ,11,12 recovering from failures,13 and even running upright on (modified...speed activities requiring large leg torques, such as clambering over rocks and climbing stairs , as well as high speed activities with moderate torques...8] McMordie, D. and Buehler, M., “Towards pronking with a hexapod robot ,” in [International Conference on Climbing and Walking Robots

Arm and leg substrate utilization and muscle adaptation after prolonged low-intensity training

DEFF Research Database (Denmark)

Helge, Jørn Wulff

2010-01-01

This review will focus on current data where substrate metabolism in arm and leg muscle is investigated and discuss the presence of higher carbohydrate oxidation and lactate release observed during arm compared with leg exercise. Furthermore, a basis for a possible difference in substrate partiti...... at comparable workloads. Finally, the influence and capacity of low-intensity training to influence metabolic fitness in the face of a limited effect on aerobic fitness will be challenged....... partitioning between endogenous and exogenous substrate during arm and leg exercise will be debated. Moreover the review will probe if differences between arm and leg muscle are merely a result of different training status rather than a qualitative difference in limb substrate regulation. Along this line...... the review will address the available studies on low-intensity training performed separately with arm or legs or as whole-body training to evaluate if this leads to different adaptations in arm and leg muscle resulting in different substrate utilization patterns during separate arm or leg exercise...

Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

Science.gov (United States)

Demšar, Ivan; Duhovnik, Jože; Lešnik, Blaž; Supej, Matej

2015-01-01

The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW), various skiing regimes were simulated. Change of Flexion Angle (CoFA) and Range of Motion (RoM) in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1°) was significantly lower compared to an intact leg (5.9 ± 1.8°) and the control group (6.5 ± 2.3°). In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2°) was significantly larger than that of the intact leg (34.7 ± 4.4°). The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing. Key points The RoM in the ski boot on the side of the prosthetic leg was smaller than the RoM of the intact leg and the control group of healthy subjects. The RoM in the ankle joint of prosthetic leg was comparable to that of the intact leg and the control group of healthy subjects. The RoM in the prosthetic knee joint was greater than the RoM in the knee joint of the

Parental smoking during pregnancy shortens offspring's legs.

Science.gov (United States)

Żądzińska, E; Kozieł, S; Borowska-Strugińska, B; Rosset, I; Sitek, A; Lorkiewicz, W

2016-12-01

One of the most severe detrimental environmental factors acting during pregnancy is foetal smoke exposure. The aim of this study was to assess the effect of maternal, paternal and parental smoking during pregnancy on relative leg length in 7- to 10-year-old children. The research conducted in the years 2001-2002 included 978 term-born children, 348 boys and 630 girls, at the age of 7-10 years. Information concerning the birth weight of a child was obtained from the health records of the women. Information about the mother's and the father's smoking habits during pregnancy and about the mothers' education level was obtained from a questionnaire. The influence of parental smoking on relative leg length, controlled for age, sex, birth weight and the mother's education, as a proxy measure of socioeconomic status, and controlled for an interaction between sex and birth weight, was assessed by an analysis of covariance, where relative leg length was the dependent variable, smoking and sex were the independent variables, and birth weight as well as the mother's education were the covariates. Three separate analyses were run for the three models of smoking habits during pregnancy: the mother's smoking, the father's smoking and both parents' smoking. Only both parents' smoking showed a significant effect on relative leg length of offspring. It is probable that foetal hypoxia caused by carbon monoxide contained in smoke decelerated the growth of the long bones of foetuses. Copyright © 2016 Elsevier GmbH. All rights reserved.

Hot Leg Piping Materials Issues

International Nuclear Information System (INIS)

V. Munne

2006-01-01

With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the space nuclear power plant (SNPP) for Project Prometheus (References a and b) the reactor outlet piping was recognized to require a design that utilizes internal insulation (Reference c). The initial pipe design suggested ceramic fiber blanket as the insulation material based on requirements associated with service temperature capability within the expected range, very low thermal conductivity, and low density. Nevertheless, it was not considered to be well suited for internal insulation use because its very high surface area and proclivity for holding adsorbed gases, especially water, would make outgassing a source of contaminant gases in the He-Xe working fluid. Additionally, ceramic fiber blanket insulating materials become very friable after relatively short service periods at working temperatures and small pieces of fiber could be dislodged and contaminate the system. Consequently, alternative insulation materials were sought that would have comparable thermal properties and density but superior structural integrity and greatly reduced outgassing. This letter provides technical information regarding insulation and materials issues for the Hot Leg Piping preconceptual design developed for the Project Prometheus space nuclear power plant (SNPP)

Design of a Single Motor Based Leg Structure with the Consideration of Inherent Mechanical Stability

Science.gov (United States)

Taha Manzoor, Muhammad; Sohail, Umer; Noor-e-Mustafa; Nizami, Muhammad Hamza Asif; Ayaz, Yasar

2017-07-01

The fundamental aspect of designing a legged robot is constructing a leg design that is robust and presents a simple control problem. In this paper, we have successfully designed a robotic leg based on a unique four bar mechanism with only one motor per leg. The leg design parameters used in our platform are extracted from design principles used in biological systems, multiple iterations and previous research findings. These principles guide a robotic leg to have minimal mechanical passive impedance, low leg mass and inertia, a suitable foot trajectory utilizing a practical balance between leg kinematics and robot usage, and the resultant inherent mechanical stability. The designed platform also exhibits the key feature of self-locking. Theoretical tools and software iterations were used to derive these practical features and yield an intuitive sense of the required leg design parameters.

33 CFR 147.817 - Sir Douglas Morpeth Tension Leg Platform safety zone.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Sir Douglas Morpeth Tension Leg... HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES SAFETY ZONES § 147.817 Sir Douglas Morpeth Tension Leg Platform safety zone. (a) Description. The Sir Douglas Morpeth Tension Leg Platform (Morpeth...

In pursuit of vehicle landmine occupant protection: Evaluating the dynamic response characteristic of the military lower extremity leg (MiL-Lx) compared to the Hybrid III (HIII) lower leg

CSIR Research Space (South Africa)

Pandelani, T

2010-09-01

Full Text Available typical mine-protected vehicle landmine blast load conditions. Tests were performed using the Lower Limb Impactor (LLI) on both the MiL-Lx leg and the Hybrid III leg, and the relative responses compared. The results show that the MiL-Lx leg appears...

The single-leg-stance test in Parkinson's disease.

Science.gov (United States)

Chomiak, Taylor; Pereira, Fernando Vieira; Hu, Bin

2015-03-01

Timed single-leg-stance test (SLST) is widely used to assess postural control in the elderly. In Parkinson's disease (PD), it has been shown that an SLST around 10 seconds or below may be a sensitive indicator of future falls. However, despite its role in fall risk, whether SLST times around 10 seconds marks a clinically important stage of disease progression has largely remained unexplored. A cross-sectional study where 27 people with PD were recruited and instructed to undertake timed SLST for both legs was conducted. Disease motor impairment was assessed with the Unified Parkinson's Disease Rating Scale Part 3 (UPDRS-III). This study found that: 1) the SLST in people with PD shows good test-retest reliability; 2) SLST values can be attributed to two non-overlapping clusters: a low (10.4 ± 6.3 seconds) and a high (47.6 ± 11.7 seconds) value SLST group; 3) only the low value SLST group can be considered abnormal when age-matched normative SLST data are taken into account for comparison; and 4) lower UPDRS-III motor performance, and the bradykinesia sub-score in particular, are only associated with the low SLST group. These results lend further support that a low SLST time around 10 seconds marks a clinically important stage of disease progression with significant worsening of postural stability in PD.

Ultrasonography of Skin Changes in Legs with Chronic Venous Disease.

Science.gov (United States)

Caggiati, A

2016-10-01

In daily practice, ultrasonography (US) is used only to designate the location and pattern of venous lesions. Skin US is not performed between routine venous investigations. Skin morphology is evaluated by the same probes used for routine Duplex evaluation of superficial veins. US findings from evident skin lesions are comparatively evaluated with those from the surrounding apparently normal skin and from the contralateral leg. Inflammation and dermal edema can be found in the apparently normal skin of C2 legs. Swollen legs show thickening of the subcutaneous layer as a result of diffuse soaking or anechoic cavities, with or without dermal edema. Chronic hypodermitis is characterized by inflammatory edema in initial phases, and by liposclerosis in advanced cases. Recrudescence of inflammation provokes focal rarefactions of the subcutaneous layer, possibly related to ulcer opening. In legs with venous disorders, sonography refines clinical evaluation of the skin and may reveal changes not highlighted by inspection. Some of these changes could require further investigation because they have not yet been explained or described. Skin sonography should improve knowledge of the natural history of skin changes, as well as contribute to a better grading of venous diseases severity In particular, US evidence of cutaneous and subcutaneous changes in C2 legs should be considered to stratify the treatment in C2 legs, by identifying those in which varicose veins are not simply a cosmetic problem. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

An analysis methodology for hot leg break mass and energy release

International Nuclear Information System (INIS)

Song, Jin Ho; Kwon, Young Min; Kim, Taek Mo; Chung, Hae Yong; Lee, Sang Jong

1996-07-01

An analysis methodology for the hot leg break mass and energy release is developed. For the blowdown period a modified CEFLASH-4A analysis is suggested. For the post-blowdown period a new computer model named COMET is developed. Differently from previous post-blowdown analysis model FLOOD3, COMET is capable of analyzing both cold leg and hot leg break cases. The cold leg break model is essentially same as that of FLOOD3 with some improvements. The analysis results by the newly proposed hot leg break model in the COMET is in the same trend as those observed in scaled-down integral experiment. And the analyses results for the UCN 3 and 4 by COMET are qualitatively and quantitatively in good agreement with those predicted by best-estimate analysis by using RELAP5/MOD3. Therefore, the COMET code is validated and can be used for the licensing analysis. 6 tabs., 82 figs., 9 refs. (Author)

[Rate of absenteeism--value and modification by work disability data].

Science.gov (United States)

Kentner, M

1999-10-01

Data on pre-retirement invalidity and incapacity to work are simple process-data gathered from routine procedures within our social system. It is therefore an obvious step to use them in describing the prevalent morbidity and relations between work and the incidence of illnesses. However, closer examinations have shown that the analysis of such secondary data does not provide particularly well-founded results, especially regarding causal relations between work itself and the so-called work-related diseases. All in all, the rate of incapacity for work is a product of illness, personal well-being, individual attitude towards work, and the social environment. The latter is influenced in particular by the management and organisational structures within a company. Therefore, few of the programmes designed to reduce the rate of incapacity to work have any great effect. They aim at the symptoms without really tackling the real causes. Low rates of incapacity to work accompanied by a lasting improvement in the overall productivity of the whole staff can only be achieved by a organisational culture that is based on raising motivation, personal well-being, and health.

Monocoque structure for the SKITTER three-legged walker

Science.gov (United States)

Bansek, Robert N.; Booth, Andrew J.; Daneman, Steven A.; Dresser, James A.; Haney, Todd G.; Johnson, Gregory R.; Lindzen, Eric C.; Montgomery, Robert C.; Warren, Andrew L.

1988-01-01

The SKITTER 2 design is a monocoque version of the proposed lunar three-legged walker. By the definition of monocoque, the body and legs are a shell with no internal ribbing or supports added for absorbing stresses. The purpose of the monocoque is to encase the elements used for power transmission, power supply, and control of the motion. The material for the structure is a vinyl ester resin, Derakane 8084. This material is easily formable and locally obtainable. The body consists of a hexagonally shaped cylinder with truncated hexagonal pyramids on the top and botton. The legs are eight inch diameter cylinders. The legs are comprised of a tibia section and a femur section. The SKITTER 2 is powered by six actuators which provide linear forces that are transformed into rotary torques by a series of chains and sprockets. The joints connect the femur to the body and the tibia to the femur. Surrounding the joints are flexible rubber hoses that fully encase the chains and sprockets. The SKITTER 2 is capable of walking upside down, righting itself after being overturned, and has the ability to perform in many environments. Applications for this walker include lunar transport or drilling, undersea exploration, and operation in severe surroundings such as arctic temperatures or high radiation.

Human thermal responses during leg-only exercise in cold water.

Science.gov (United States)

Golden, F S; Tipton, M J

1987-10-01

1. Exercise during immersion in cold water has been reported by several authors to accelerate the rate of fall of core temperature when compared with rates seen during static immersion. The nature of the exercise performed, however, has always been whole-body in nature. 2. In the present investigation fifteen subjects performed leg exercise throughout a 40 min head-out immersion in water at 15 degrees C. The responses obtained were compared with those seen when the subjects performed an identical static immersion. 3. Aural and rectal temperatures were found to fall by greater amounts during static immersion. 4. It is concluded that 'the type of exercise performed' should be included in the list of factors which affect core temperature during cold water immersion.

Dynamically Stable Legged Locomotion.

Science.gov (United States)

1983-01-27

digitai~y thro)ugh a ribbon cable. lhe dcsign effort required to mount power sources and computing u(m board would hive distracted us fiorn our main...angular momentum. "The model used in this paper, shown in Fig. 6-1, has 3 single springy leg that articular •s ,ith respect to a body about a simple hince

Postural control of typical developing boys during the transition from double-leg stance to single-leg stance.

Science.gov (United States)

Deschamps, Kevin; Staes, Filip; Peerlinck, Kathelijne; Van Geet, Kristel; Hermans, Cedric; Lobet, Sebastien

2017-02-01

Literature is lacking information about postural control performance of typically developing children during a transition task from double-leg stance to single-leg stance. The purpose of the present study was therefore to evaluate the clinical feasibility of a transition task in typical developing age groups as well as to study the correlation between associated balance measures and age.Thirty-three typically developing boys aged 6-20 years performed a standard transition task from DLS to SLS with eyes open (EO) and eyes closed (EC). Balance features derived from the center of pressure displacement captured by a single force platform were correlated with age on the one hand and considered for differences in the perspective of limb dominance on the other hand.All TDB (typically developing boys) were able to perform the transition task with EO. With respect to EC condition, all TDB from the age group 6-7 years and the youngest of the age group 8-12 years (N = 4) were unable to perform the task. No significant differences were observed between the balance measures of the dominant and non-dominant limbs.With respect to EO condition, correlation analyses indicated that time to new stability point (TNSP) as well as the sway measure after this TNSP were correlated with age (p postural balance of typically developing children during walking, running, sit-to-stand, and bipodal and unipodal stance has been well documented in the literature. • These reference data provided not only insight into the maturation process of the postural control system, but also served in diagnosing and managing functional repercussions of neurological and orthopedic pathologies. What is New: • Objective data regarding postural balance of typical developing children during a transition task from double-leg stance to single-leg stance. • Insight into the role of maturation on the postural control system.

Fatal pox infection in a rough-legged hawk

Science.gov (United States)

Pearson, G.L.; Pass, D.A.; Beggs, E.C.

1975-01-01

Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

Flexible thermoelectric generator using bulk legs and liquid metal interconnects for wearable electronics

International Nuclear Information System (INIS)

Suarez, Francisco; Parekh, Dishit P.; Ladd, Collin; Vashaee, Daryoosh; Dickey, Michael D.; Öztürk, Mehmet C.

2017-01-01

Highlights: •Flexible thermoelectric generator (TEG) with bulk legs. •Flexible thermoelectric generator with liquid metal interconnects. •Flexible TEG with potential to match the performance of rigid TEGs. •Flexible TEG for wearable electronics. -- Abstract: Interest in wearable electronics for continuous, long-term health and performance monitoring is rapidly increasing. The reduction in power levels consumed by sensors and electronic circuits accompanied by the advances in energy harvesting methods allows for the realization of self-powered monitoring systems that do not have to rely on batteries. For wearable electronics, thermoelectric generators (TEGs) offer the unique ability to continuously convert body heat into usable energy. For body harvesting, it is preferable to have TEGs that are thin, soft and flexible. Unfortunately, the performances of flexible modules reported to date have been far behind those of their rigid counterparts. This is largely due to lower efficiencies of the thermoelectric materials, electrical or thermal parasitic losses and limitations on leg dimensions posed by the synthesis techniques. In this work, we present an entirely new approach and explore the possibility of using standard bulk legs in a flexible package. Bulk thermoelectric legs cut from solid ingots are far superior to thermoelectric materials synthesized using other techniques. A key enabler of the proposed technology is the use of EGaIn liquid metal interconnects, which not only provide extremely low interconnect resistance but also stretchability with self-healing, both of which are essential for flexible TE modules. The results suggest that this novel approach can finally produce flexible TEGs that have the potential to challenge the rigid TEGs and provide a pathway for the realization of self-powered wearable electronics.

The Interday Measurement Consistency of and Relationships Between Hamstring and Leg Musculo-articular Stiffness.

Science.gov (United States)

Waxman, Justin P; Schmitz, Randy J; Shultz, Sandra J

2015-10-01

Hamstring stiffness (K(HAM)) and leg stiffness (K(LEG)) are commonly examined relative to athletic performance and injury risk. Given these may be modifiable, it is important to understand day-to-day variations inherent in these measures before use in training studies. In addition, the extent to which K(HAM) and K(LEG) measure similar active stiffness characteristics has not been established. We investigated the interday measurement consistency of K(HAM) and K(LEG), and examined the extent to which K(LEG) predicted K(HAM) in 6 males and 9 females. K(HAM) was moderately consistent day-to-day (ICC(2,5) = .71; SEM = 76.3 N·m(-1)), and 95% limits of agreement (95% LOA) revealed a systematic bias with considerable absolute measurement error (95% LOA = 89.6 ± 224.8 N·m(-1)). Day-to-day differences in procedural factors explained 59.4% of the variance in day-to-day differences in K(HAM). Bilateral and unilateral K(LEG) was more consistent (ICC(2,3) range = .87-.94; SEM range = 1.0-2.91 kN·m(-1)) with lower absolute error (95% LOA bilateral= -2.0 ± 10.3; left leg = -0.36 ± 3.82; right leg = -1.05 ± 3.61 kN·m(-1)). K(LEG) explained 44% of the variance in K(HAM) (P consistent and precise K(HAM) measures. The ease and consistency of K(LEG), and moderate correlation with K(HAM), may steer clinicians toward K(LEG) when measuring lower-extremity stiffness for screening studies and monitoring the effectiveness of training interventions over time.

Cohesive taping and short-leg casting in acute low-type ankle sprains in physically active patients.

Science.gov (United States)

Uslu, Mustafa; Inanmaz, Mustafa E; Ozsahin, Mustafa; Isık, Cengiz; Arıcan, Mehmet; Gecer, Yavuz

2015-07-01

Cohesive taping is commonly used for the prevention or treatment of ankle sprain injuries. Short-leg cast immobilization or splinting is another treatment option in such cases. To determine the clinical efficacy and antiedema effects of cohesive taping and short-leg cast immobilization in acute low-type ankle sprains of physically active patients, we performed a preliminary clinical study to assess objective evidence for edema and functional patient American Orthopaedic Foot and Ankle Society (AOFAS) scores with these alternative treatments. Fifty-nine physically active patients were included: 32 in the taping group and 27 in the short-leg cast group within a year. If a sprain was moderate (grade II) or mild (grade I), we used functional taping or short-leg cast immobilization for 10 days. We evaluated the edema and the functional scores of the injured ankle using the AOFAS Clinical Rating System on days 1, 10, and 100. In each group, edema significantly decreased and AOFAS scores increased indicating that both treatment methods were effective. With the numbers available, no statistically significant difference could be detected. Each treatment method was effective in decreasing the edema and increasing the functional scores of the ankle. At the beginning of treatment, not only the level of edema but also the initial functional scores of the ankle and examinations are important in making decisions regarding the optimal treatment option.

Influence of Manual Labor at Work on Muscular Fitness and Its Relationship With Work Performance.

Science.gov (United States)

Ryan, Eric D; Thompson, Brennan J; Sobolewski, Eric J

2016-10-01

The present study examined the influence of workplace manual labor on measures of muscular fitness, with a secondary aim to investigate the relationship between muscular fitness and work performance in blue-collar (BC) workers. Leg extension isokinetic strength at slow and fast velocities, hamstring and hip-flexor flexibility, and low back muscular endurance were examined in young and older BC workers and white-collar (WC) controls, while work performance was examined in the BC cohort. There were no differences in muscular fitness variables between BC and WC groups; however, the older men had lower low back muscular endurance (-43.0%) and strength at slow (-9.4%) and fast (-12.7%) velocities. Work performance was associated with strength at fast velocities (r = 0.633) in the older BC workers. Leg strength may influence work performance, with higher velocities becoming more important in older workers.

Military boot attenuates axial loading to the lower leg.

Science.gov (United States)

Yoganandan, Narayan; Schlick, Michael; Arun, Mike W J; Pintar, Frank A

2014-01-01

Biomechanical tests to understand injury mechanisms and derive injury tolerance information using Post-Mortem Human Subjects (PMHS) have not used foot protection and they have primarily focused on civilian environments such as automotive and athletic- and sports-related events. As military personnel use boots, tests with the boot are required to understand their effect on attenuating lower leg loads. The purpose of this study was therefore, to determine the modulation of human lower leg kinematics with boot compressions and share of the force absorbed by the boot from underbody blast loading. Axial impacts were delivered to the Hybrid III dummy lower leg in the neutral position. The dummy leg was instrumented with its internal upper and lower tibia load cells, and in addition, a knee load cell was attached to the proximal end. Tests were conducted at 4.4 to 8.9 m/s, with and without boots, and repeat tests were done. Morphologies of the force-time responses were similar at the three load cell locations and for all input combinations and booted and unbooted conditions. However, booted tests resulted in considerably lower maximum forces (approximately two-third reduction) than unbooted tests. These results clearly show that boots can absorb a considerable share of the impact energy and decrease impact loads transmitted to the lower leg under vertical loading, thus necessitating the generation of tolerance data using PMHS for this environment.

Dynamic Leg Exercise Improves Tolerance to Lower Body Negative Pressure

Science.gov (United States)

Watenpaugh, D. E.; Ballard, R. E.; Stout, M. S.; Murthy, G.; Whalen, R. T.; Hargens, A. R.

1994-01-01

These results clearly demonstrate that dynamic leg exercise against the footward force produced by LBNP substantially improves tolerance to LBNP, and that even cyclic ankle flexion without load bearing also increases tolerance. This exercise-induced increase of tolerance was actually an underestimate, because subjects who completed the tolerance test while exercising could have continued for longer periods. Exercise probably increases LBNP tolerance by multiple mechanisms. Tolerance was increased in part by skeletal muscle pumping venous blood from the legs. Rosenhamer and Linnarsson and Rosenhamer also deduced this for subjects cycling during centrifugation, although no measurements of leg volume were made in those studies: they found that male subjects cycling at 98 W could endure 3 Gz centrifugation longer than when they remained relaxed during centrifugation. Skeletal muscle pumping helps maintain cardiac filling pressure by opposing gravity-, centrifugation-, or LBNP-induced accumulation of blood and extravascular fluid in the legs.

Decreased hematocrit-to-viscosity ratio and increased lactate dehydrogenase level in patients with sickle cell anemia and recurrent leg ulcers.

Directory of Open Access Journals (Sweden)

Philippe Connes

Full Text Available Leg ulcer is a disabling complication in patients with sickle cell anemia (SCA but the exact pathophysiological mechanisms are unknown. The aim of this study was to identify the hematological and hemorheological alterations associated with recurrent leg ulcers. Sixty-two SCA patients who never experienced leg ulcers (ULC- and 13 SCA patients with a positive history of recurrent leg ulcers (ULC+--with no leg ulcers at the time of the study--were recruited. All patients were in steady state condition. Blood was sampled to perform hematological, biochemical (hemolytic markers and hemorheological analyses (blood viscosity, red blood cell deformability and aggregation properties. The hematocrit-to-viscosity ratio (HVR, which reflects the red blood cell oxygen transport efficiency, was calculated for each subject. Patients from the ULC+ group were older than patients from the ULC- group. Anemia (red blood cell count, hematocrit and hemoglobin levels was more pronounced in the ULC+ group. Lactate dehydrogenase level was higher in the ULC+ group than in the ULC- group. Neither blood viscosity, nor RBC aggregation properties differed between the two groups. HVR was lower and RBC deformability tended to be reduced in the ULC+ group. Our study confirmed increased hemolytic rate and anemia in SCA patients with leg ulcers recurrence. Furthermore, our data suggest that although systemic blood viscosity is not a major factor involved in the pathophysiology of this complication, decreased red blood cell oxygen transport efficiency (i.e., low hematocrit/viscosity ratio may play a role.

Experimental research on pedestrian lower leg impact

Science.gov (United States)

Constantin, B. A.; Iozsa, D. M.; Stan, C.

2017-10-01

The present paper is centred on the research of deceleration measured at the level of the lower leg during a pedestrian impact in multiple load cases. Basically, the used methodology for physical test setup is similar to EuroNCAP and European Union regulatory requirements. Due cost reduction reasons, it was not used a pneumatic system in order to launch the lower leg impactor in the direction of the vehicle front-end. During the test it was used an opposite solution, namely the vehicle being in motion, aiming the standstill lower leg impactor. The impactor has similar specifications to those at EU level, i.e. dimensions, materials, and principle of measurement of the deceleration magnitude. Therefore, all the results obtained during the study comply with the requirements of both EU regulation and EuroNCAP. As a limitation, due to unavailability of proper sensors in the equipment of the lower leg impactor, that could provide precise results, the bending angle, the shearing and the detailed data at the level of knee ligaments were not evaluated. The knee joint should be improved for future studies as some bending angles observed during the post processing of several impact video files were too high comparing to other studies. The paper highlights the first pedestrian impact physical test conducted by the author, following an extensive research in the field. Deceleration at the level of pedestrian knee can be substantially improved by providing enough volume between the bumper fascia and the front-end structure and by using pedestrian friendly materials for shock absorbers, such as foams.

Differences in kinematics of single leg squatting between anterior cruciate ligament-injured patients and healthy controls.

Science.gov (United States)

Yamazaki, J; Muneta, T; Ju, Y J; Sekiya, I

2010-01-01

Seventy to eighty percent of all anterior cruciate ligament (ACL) injuries are due to non-contact injury mechanisms. It has been reported that the majority of injuries due to single leg landing come from valgus positioning of the lower leg. Preventing valgus positioning during single leg landing is expected to help reduce the number of ACL injuries. We found that many ACL-deficient patients cannot perform stable single leg squatting. Therefore, we performed 3D motion analysis of the single-legged half squat for ACL-injured patients to evaluate its significance as a risk factor for ACL injuries. We evaluated the relative angles between the body, thigh, and lower leg using an electromagnetic device during single leg half squatting performed by 63 ACL-injured patients (32 males, 31 females) the day before ACL reconstruction and by 26 healthy control subjects with no knee problems. The uninjured leg of ACL-injured male subjects demonstrated significantly less external knee rotation than that of the dominant leg of the male control. The uninjured leg of ACL-injured female subjects demonstrated significantly more external hip rotation and knee flexion and less hip flexion than that of the dominant leg of the female control. Comparing injured and uninjured legs, the injured leg of male subjects demonstrated significantly less external knee and hip rotation, less knee flexion, and more knee varus than that of the uninjured leg of male subjects. The injured leg of female subjects demonstrated more knee varus than that of the uninjured leg of female subjects. Regarding gender differences, female subjects demonstrated significantly more external hip rotation and knee valgus than male subjects did in both the injured and uninjured legs (P < 0.05). The current kinematic study exhibited biomechanical characteristics of female ACL-injured subjects compared with that of control groups. Kinematic correction during single leg half squat would reduce ACL reinjury in female ACL

Operation analysis of a Chebyshev-Pantograph leg mechanism for a single DOF biped robot

Science.gov (United States)

Liang, Conghui; Ceccarelli, Marco; Takeda, Yukio

2012-12-01

In this paper, operation analysis of a Chebyshev-Pantograph leg mechanism is presented for a single degree of freedom (DOF) biped robot. The proposed leg mechanism is composed of a Chebyshev four-bar linkage and a pantograph mechanism. In contrast to general fully actuated anthropomorphic leg mechanisms, the proposed leg mechanism has peculiar features like compactness, low-cost, and easy-operation. Kinematic equations of the proposed leg mechanism are formulated for a computer oriented simulation. Simulation results show the operation performance of the proposed leg mechanism with suitable characteristics. A parametric study has been carried out to evaluate the operation performance as function of design parameters. A prototype of a single DOF biped robot equipped with two proposed leg mechanisms has been built at LARM (Laboratory of Robotics and Mechatronics). Experimental test shows practical feasible walking ability of the prototype, as well as drawbacks are discussed for the mechanical design.

Superconductivity in doped two-leg ladder cuprates

International Nuclear Information System (INIS)

Qin Jihong; Yuan Feng; Feng Shiping

2006-01-01

Within the t-J ladder model, superconductivity with a modified d-wave symmetry in doped two-leg ladder cuprates is investigated based on the kinetic energy driven superconducting mechanism. It is shown that the spin-liquid ground-state at the half-filling evolves into the superconducting ground-state upon doping. In analogy to the doping dependence of the superconducting transition temperature in the planar cuprate superconductors, the superconducting transition temperature in doped two-leg ladder cuprates increases with increasing doping in the underdoped regime, and reaches a maximum in the optimal doping, then decreases in the overdoped regime

Two-legged walking robot prescribed motion on a rough cylinder

Science.gov (United States)

Golubev, Yury; Melkumova, Elena

2018-05-01

The motion of a walking robot with n legs, that ensure the desired motion of the robot body, is described using general dynamics theoretical framework. When each of the robot legs contacts the surface in a single foothold, the momentum and angular momentum theorems yield a system of six differential equations that form a complete description of the robot motion. In the case of two-leg robot (n = 2) the problem of the existence of the solution can be reduced to a system of algebraic inequalities. Using numerical analysis, the classification of footholds positions for different values of the friction coefficient is obtained.

STRUCTURE OF PROMINENCE LEGS: PLASMA AND MAGNETIC FIELD

Energy Technology Data Exchange (ETDEWEB)

Levens, P. J.; Labrosse, N. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Schmieder, B. [Observatoire de Paris, Meudon, F-92195 (France); Ariste, A. López, E-mail: p.levens.1@research.gla.ac.uk [Institut de Recherche en Astrophysique et Planétologie, Toulouse (France)

2016-02-10

We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrograph, and the Hinode/Solar Optical Telescope (SOT) instrument. Along with spectropolarimetry provided by the Télescope Héliographique pour l’Etude du Magnétisme et des Instabilités Solaires telescope we have coverage of both optically thick emission lines and magnetic field information. AIA reveals that the two legs of the prominence are strongly absorbing structures which look like they are rotating, or oscillating in the plane of the sky. The two prominence legs, which are both very bright in Ca ii (SOT), are not visible in the IRIS Mg ii slit-jaw images. This is explained by the large optical thickness of the structures in Mg ii, which leads to reversed profiles, and hence to lower integrated intensities at these locations than in the surroundings. Using lines formed at temperatures lower than 1 MK, we measure relatively low Doppler shifts on the order of ±10 km s{sup −1} in the tornado-like structure. Between the two legs we see loops in Mg ii, with material flowing from one leg to the other, as well as counterstreaming. It is difficult to interpret our data as showing two rotating, vertical structures that are unrelated to the loops. This kind of “tornado” scenario does not fit with our observations. The magnetic field in the two legs of the prominence is found to be preferentially horizontal.

RSRM Nozzle-to-Case Joint J-leg Development

Science.gov (United States)

Albrechtsen, Kevin U.; Eddy, Norman F.; Ewing, Mark E.; McGuire, John R.

2003-01-01

Since the beginning of the Space Shuttle Reusable Solid Rocket Motor (RSRM) program, nozzle-to-case joint polysulfide adhesive gas paths have occurred on several flight motors. These gas paths have allowed hot motor gases to reach the wiper O-ring. Even though these motors continue to fly safely with this condition, a desire was to reduce such occurrences. The RSRM currently uses a J-leg joint configuration on case field joints and igniter inner and outer joints. The J-leg joint configuration has been successfully demonstrated on numerous RSRM flight and static test motors, eliminating hot gas intrusion to the critical O-ring seals on these joints. Using the proven technology demonstrated on the case field joints and igniter joints, a nozzle-to-case joint J-leg design was developed for implementation on RSRM flight motors. This configuration provides an interference fit with nozzle fixed housing phenolics at assembly, with a series of pressurization gaps incorporated outboard of the joint mating surface to aid in joint pressurization and to eliminate any circumferential flow in this region. The joint insulation is bonded to the nozzle phenolics using the same pressure sensitive adhesive used in the case field joints and igniter joints. An enhancement to the nozzle-to-case joint J-leg configuration is the implementation of a carbon rope thermal barrier. The thermal barrier is located downstream of the joint bondline and is positioned within the joint in a manner where any hot gas intrusion into the joint passes through the thermal barrier, reducing gas temperatures to a level that would not affect O-rings downstream of the thermal barrier. This paper discusses the processes used in reaching a final nozzle-to-case joint J-leg design, provides structural and thermal results in support of the design, and identifies fabrication techniques and demonstrations used in arriving at the final configuration.

Restless Legs Syndrome in a Nigerian Elderly Population

Science.gov (United States)

Fawale, Michael B.; Ismaila, Isiaka Alani; Mustapha, Adekunle F.; Komolafe, Morenikeji A.; Adedeji, Tewogbade A.

2016-01-01

Study Objectives: The prevalence of restless legs syndrome (RLS) is highest in the elderly in Caucasian populations; the prevalence of RLS in elderly Africans is not known. This study aimed at determining the frequency and associations of RLS in a Nigerian elderly population. Methods: The study population comprised of 633 consecutive elderly individuals aged 65–105 years attending the general outpatient clinic of the State Hospital, Ilesa, for minor complaints and routine check-up. The diagnosis of RLS was made using the 2003 minimal criteria of the International Restless Legs Syndrome Study Group. Relevant sociodemographic and clinical data, including sleep duration, were also obtained. Results: Restless legs syndrome was found in 3.5% of the study population with a male-female ratio of 2:1. There was no significant age (p = 0.427) or gender (p = 0.178) influence on the prevalence of RLS except in the 75- to 84-year age group where there was significant male preponderance (p = 0.044). A strong independent association between RLS and sleep duration (OR, 3.229; 95% CI, 1.283–8.486; p = 0.013) and past history of head injury (OR, 4.691; 95% CI, 1.750–12.577; p = 0.002) was found. Conclusions: Our finding support previous reports of a possible lower prevalence of RLS in Africans. Restless legs syndrome independently increases the odds of habitual sleep curtailment in elderly individuals. Head injury may be a risk factor for future RLS; this requires further investigation as indirect evidence for a possible link between RLS and traumatic brain injury exists. Citation: Fawale MB, Ismaila IA, Mustapha AF, Komolafe MA, Adedeji TA. Restless legs syndrome in a Nigerian elderly population. J Clin Sleep Med 2016;12(7):965–972. PMID:27070251

Bioinspired legged-robot based on large deformation of flexible skeleton

International Nuclear Information System (INIS)

Mayyas, Mohammad

2014-01-01

In this article we present STARbot, a bioinspired legged robot capable of multiple locomotion modalities by using large deformation of its skeleton. We construct STARbot by using origami-style folding of flexible laminates. The long-term goal is to provide a robotic platform with maximum mobility on multiple surfaces. This paper particularly studies the quasistatic model of STARbot’s leg under different conditions. We describe the large elastic deformation of a leg under external force, payload, and friction by using a set of non-dimensional, nonlinear approximate equations. We developed a test mechanism that models the motion of a leg in STARbot. We augmented several foot shapes and then tested them on soft to rough grounds. Both simulation and experimental findings were in good agreement. We utilized the model to develop several scales of tri and quad STARbot. We demonstrated the capability of these robots to locomote by combining their leg deformations with their foot motions. The combination provided a design platform for an active suspension STARbot with controlled foot locomotion. This included the ability of STARbot to change size, run over obstacles, walk and slide. Furthermore, in this paper we discuss a cost effective manufacturing and production method for manufacturing STARbot. (paper)

Bioinspired legged-robot based on large deformation of flexible skeleton.

Science.gov (United States)

Mayyas, Mohammad

2014-11-11

In this article we present STARbot, a bioinspired legged robot capable of multiple locomotion modalities by using large deformation of its skeleton. We construct STARbot by using origami-style folding of flexible laminates. The long-term goal is to provide a robotic platform with maximum mobility on multiple surfaces. This paper particularly studies the quasistatic model of STARbot's leg under different conditions. We describe the large elastic deformation of a leg under external force, payload, and friction by using a set of non-dimensional, nonlinear approximate equations. We developed a test mechanism that models the motion of a leg in STARbot. We augmented several foot shapes and then tested them on soft to rough grounds. Both simulation and experimental findings were in good agreement. We utilized the model to develop several scales of tri and quad STARbot. We demonstrated the capability of these robots to locomote by combining their leg deformations with their foot motions. The combination provided a design platform for an active suspension STARbot with controlled foot locomotion. This included the ability of STARbot to change size, run over obstacles, walk and slide. Furthermore, in this paper we discuss a cost effective manufacturing and production method for manufacturing STARbot.

Leg disorders in broiler chickens: prevalence, risk factors and prevention.

Directory of Open Access Journals (Sweden)

Toby G Knowles

Full Text Available Broiler (meat chickens have been subjected to intense genetic selection. In the past 50 years, broiler growth rates have increased by over 300% (from 25 g per day to 100 g per day. There is growing societal concern that many broiler chickens have impaired locomotion or are even unable to walk. Here we present the results of a comprehensive survey of commercial flocks which quantifies the risk factors for poor locomotion in broiler chickens. We assessed the walking ability of 51,000 birds, representing 4.8 million birds within 176 flocks. We also obtained information on approximately 150 different management factors associated with each flock. At a mean age of 40 days, over 27.6% of birds in our study showed poor locomotion and 3.3% were almost unable to walk. The high prevalence of poor locomotion occurred despite culling policies designed to remove severely lame birds from flocks. We show that the primary risk factors associated with impaired locomotion and poor leg health are those specifically associated with rate of growth. Factors significantly associated with high gait score included the age of the bird (older birds, visit (second visit to same flock, bird genotype, not feeding whole wheat, a shorter dark period during the day, higher stocking density at the time of assessment, no use of antibiotic, and the use of intact feed pellets. The welfare implications are profound. Worldwide approximately 2 x 10(10 broilers are reared within similar husbandry systems. We identify a range of management factors that could be altered to reduce leg health problems, but implementation of these changes would be likely to reduce growth rate and production. A debate on the sustainability of current practice in the production of this important food source is required.

Case study: survey of patient satisfaction with prosthesis quality and design among below-knee prosthetic leg socket users.

Science.gov (United States)

Mohd Hawari, Nurhanisah; Jawaid, Mohammad; Md Tahir, Paridah; Azmeer, Raja Ahmad

2017-11-01

The aim of this case study was to explore patient satisfaction with the quality of prosthetic leg sockets intended for persons with lower limb amputations. A qualitative study based on in-depth interviews, preceded by a questionnaire session, was carried out with patients from the Rehabilitation Center and Hospital in Malaysia. Twelve out-patient and in-patient amputees with lower limb amputations, specifically below-knee amputations, were chosen randomly. The analysis of patients' narratives aimed to identify the functional and esthetic characteristics of currently used prosthetic leg sockets and any problems related to them. The obtained results indicated that out of the 12 participants, 41.7% and 25% were satisfied and somewhat satisfied with their current prosthetic sockets. Durability and comfort were rated by the participants as the most important characteristics of prosthetic sockets, with 83.3%. As regards the esthetic appearance of the socket, 66.7% of the respondents considered that the most important feature was the material from which the socket was fabricated. Thus, we conclude that current satisfaction levels with the quality of prosthetic sockets among amputees in Malaysia are suitable, prosthesis being preferred by many amputees. The results can be used to direct future research on cosmesis and functionality of prosthetic socket design. Implications for Rehabilitation Case study will help participants to get cost effective prosthetic leg socket. Develop prosthetic leg socket comfortable as comparative to existing one. Help Malaysian government to make policy to develop local prosthetic leg socket at affordable price.

Quality of Life in People with Leg Ulcer, Integrative Review

Directory of Open Access Journals (Sweden)

Daniela Alves

2016-04-01

Full Text Available Objective: To identify the main changes in the daily life of people with leg ulcer and how that affects the person’s quality of life. Methodology: We used the methodology PI [C] OD and selected four research articles, taken from EBSCO, PubMed, and EWMA. Results: The main changes identified in the people’s daily live with leg ulcers are physical (pain, decreased mobility, presence of exudate, bad smell from the wound and change in the style of clothing, psychological (sleep disorders, depression, anxiety, feelings of rejection and low self-steem, social (isolation, restriction in leisure activities, inability to perform household chores. Conclusions: The literature about the person’s quality of life with leg ulcer reported a significant impact in the daily life. The care provided by nurses should be centered on the person, integrating all the kind of needs and the leg ulcer must not be the sole focus of care

Leg stiffness during phases of countermovement and take-off in vertical jump.

Science.gov (United States)

Struzik, Artur; Zawadzki, Jerzy

2013-01-01

With respect to cyclic movements such as human gait, running or hopping, leg stiffness is a little variable parameter. The aim of this study was to investigate changes in leg stiffness during the phase of countermovement and take-off when performing a single maximum counter-movement jump. Kistler force plates and a BTS SMART system for comprehensive motion analysis were employed in the study. The study covered a group of 12 athletes from university basketball teams. Leg stiffness was calculated in those parts of countermovement and take-off phases where its level is relatively constant and the relationship F(Δl) is similar to linear one. Mean total stiffness (±SD) in both legs in the countermovement phase amounted to 6.5 ± 1.5 kN/m, whereas during the take-off phase this value was 6.9 ± 1 kN/m. No statistically significant differences were found between leg stiffness during the countermovement phase and takeoff phase in the study group at the level of significance set at α = 0.05. This suggests that the leg stiffness in phase of countermovement and phase of take-off are much similar to each other, despite different function of both phases. Similar to cyclic movements, leg stiffness turned out relatively constant when performing a single vertical jump. There are also reported statistically significant correlations between body mass, body height, length of lower limbs and leg stiffness. The stiffness analysed by the authors should be understood as quasi-stiffness because the measurements of ΔF(Δl) were made during transient states where inertia and dumping forces are likely to affect the final result.

Effects of leg dominance on performance of ballet turns (pirouettes) by experienced and novice dancers.

Science.gov (United States)

Lin, Chia-Wei; Su, Fong-Chin; Wu, Hong-Wen; Lin, Cheng-Feng

2013-01-01

Turns (pirouettes) are an important movement in ballet and may be affected by "lateral bias". This study investigated physiological differences exhibited by experienced and novice dancers, respectively, when performing pirouette with dominant and non-dominant leg supports, respectively. Thirteen novice and 13 experienced dancers performed turns on dominant or non-dominant legs. The maximum ankle plantarflexion, knee extension and hip extension were measured during the single-leg support phase. The inclination angle of rotation axis is the angle between instantaneous rotation axis and global vertical axis in the early single-leg support phase. Both groups exhibited a greater hip extension, knee extension, and ankle plantarflexion when performing a turn on the non-dominant leg. For experienced dancers, the inclination angle of rotation axis during the pre-swing phase was generally smaller for dominant leg support than non-dominant leg. However, no significant difference was found in inclination angle of rotation axis of novice dancers. For experienced dancers, an improved performance is obtained when using the dominant leg for support. By contrast, for novice dancers, the performance is independent of choice of support leg. The significant lateral bias in experienced dancers indicates the possible influence of training. That is, repetitive rehearsal on the preferred leg strengthens the impact of side dominance in experienced dancers.

How to determine leg dominance: The agreement between self-reported and observed performance in healthy adults.

Directory of Open Access Journals (Sweden)

Nicky van Melick

Full Text Available Since decades leg dominance is suggested to be important in rehabilitation and return to play in athletes with anterior cruciate ligament injuries. However, an ideal method to determine leg dominance in relation to task performance is still lacking.To test the agreement between self-reported and observed leg dominance in bilateral mobilizing and unilateral stabilizing tasks, and to assess whether the dominant leg switches between bilateral mobilizing tasks and unilateral stabilizing tasks.Cross-sectional study.Forty-one healthy adults: 21 men aged 36 ± 17 years old and 20 women aged 36 ±15 years old.Participants self-reported leg dominance in the Waterloo Footedness Questionnaire-Revised (WFQ-R, and leg dominance was observed during performance of four bilateral mobilizing tasks and two unilateral stabilizing tasks. Descriptive statistics and crosstabs were used to report the percentages of agreement.The leg used to kick a ball had 100% agreement between the self-reported and observed dominant leg for both men and women. The dominant leg in kicking a ball and standing on one leg was the same in 66.7% of the men and 85.0% of the women. The agreement with jumping with one leg was lower: 47.6% for men and 70.0% for women.It is appropriate to ask healthy adults: "If you would shoot a ball on a target, which leg would you use to shoot the ball?" to determine leg dominance in bilateral mobilizing tasks. However, a considerable number of the participants switched the dominant leg in a unilateral stabilizing task.

H:q ratios and bilateral leg strength in college field and court sports players.

Science.gov (United States)

Cheung, Roy T H; Smith, Andrew W; Wong, Del P

2012-06-01

One of the key components in sports injury prevention is the identification of imbalances in leg muscle strength. However, different leg muscle characteristics may occur in large playing area (field) sports and small playing area (court) sports, which should be considered in regular injury prevention assessment. This study examined the isokinetic hamstrings-to-quadriceps (H:Q) ratio and bilateral leg strength balance in 40 male college (age: 23.4 ± 2.5 yrs) team sport players (field sport = 23, soccer players; court sport = 17, volleyball and basketball players). Five repetitions of maximal knee concentric flexion and concentric extension were performed on an isokinetic dynamometer at two speeds (slow: 60°·s(-1) and fast: 300°·s(-1)) with 3 minutes rest between tests. Both legs were measured in counterbalanced order with the dominant leg being determined as the leg used to kick a ball. The highest concentric peak torque values (Nm) of the hamstrings and quadriceps of each leg were analyzed after body mass normalization (Nm·kg(-1)). Court sport players showed significantly weaker dominant leg hamstrings muscles at both contraction speeds (P Sport-specific leg muscle strength was evident in college players from field and court sports. These results suggest the need for different muscle strength training and rehabilitation protocols for college players according to the musculature requirements in their respective sports.

Predicting work Performance through selection interview ratings and Psychological assessment

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Liziwe Nzama

2008-11-01

Full Text Available The aim of the study was to establish whether selection interviews used in conjunction with psychological assessments of personality traits and cognitive functioning contribute to predicting work performance. The sample consisted of 102 managers who were appointed recently in a retail organisation. The independent variables were selection interview ratings obtained on the basis of structured competency-based interview schedules by interviewing panels, fve broad dimensions of personality defned by the Five Factor Model as measured by the 15 Factor Questionnaire (15FQ+, and cognitive processing variables (current level of work, potential level of work, and 12 processing competencies measured by the Cognitive Process Profle (CPP. Work performance was measured through annual performance ratings that focused on measurable outputs of performance objectives. Only two predictor variables correlated statistically signifcantly with the criterion variable, namely interview ratings (r = 0.31 and CPP Verbal Abstraction (r = 0.34. Following multiple regression, only these variables contributed signifcantly to predicting work performance, but only 17.8% of the variance of the criterion was accounted for.

Asymmetry between the Dominant and Non-Dominant Legs in the Kinematics of the Lower Extremities during a Running Single Leg Jump in Collegiate Basketball Players.

Science.gov (United States)

Sugiyama, Takashi; Kameda, Mai; Kageyama, Masahiro; Kiba, Kazufusa; Kanehisa, Hiroaki; Maeda, Akira

2014-12-01

The present study aimed to clarify the asymmetry between the dominant (DL) and non-dominant takeoff legs (NDL) in terms of lower limb behavior during running single leg jumps (RSJ) in collegiate male basketball players in relation to that of the jump height. Twenty-seven players performed maximal RSJ with a 6 m approach. Three-dimensional kinematics data during RSJ was collected using a 12 Raptor camera infrared motion analysis system (MAC 3D system) at a sampling frequency of 500 Hz. The symmetry index in the jump heights and the kinematics variables were calculated as {2 × (DL - NDL) / (DL + NDL)} × 100. The run-up velocity was similar between the two legs, but the jump height was significantly higher in the DL than in the NDL. During the takeoff phase, the joint angles of the ankle and knee were significantly larger in the DL than the NDL. In addition, the contact time for the DL was significantly shorter than that for the NDL. The symmetry index of the kinematics for the ankle joint was positively correlated with that of jump height, but that for the knee joint was not. The current results indicate that, for collegiate basketball players, the asymmetry in the height of a RSJ can be attributed to that in the joint kinematics of the ankle during the takeoff phase, which may be associated with the ability to effectively transmit run-up velocity to jump height. Key pointsAsymmetry of height during running single leg jump between two legs is due to the behavior of the ankle joint (i.e. stiffer the ankle joint and explosive bounding).The dominant leg can transmit run-up velocity into the vertical velocity at takeoff phase to jump high compared with the non-dominant leg.Basketball players who have a greater asymmetry of the RSJ at the collegiate level could be assessed as non-regulars judging by the magnitude of asymmetry.

Genetic correlations between claw health and feet and leg conformation in Norwegian Red cows.

Science.gov (United States)

Ødegård, C; Svendsen, M; Heringstad, B

2014-07-01

The aim of this study was to estimate genetic correlations between claw disorders and feet and leg conformation traits in Norwegian Red cows. A total of 188,928 cows with claw health status recorded at claw trimming from 2004 to September 2013 and 210,789 first-lactation cows with feet and leg conformation scores from 2001 to September 2013 were included in the analyses. Traits describing claw health were corkscrew claw, infectious claw disorders (dermatitis, heel horn erosion, and interdigital phlegmon), and laminitis-related claw disorders (sole ulcer, white line disorder, and hemorrhage of sole and white line). The feet and leg conformation traits were rear leg rear view (new and old definition), rear leg side view, foot angle, and hoof quality. Feet and leg conformation traits were scored linearly from 1 to 9, with optimum scores depending on the trait. Claw disorders were defined as binary (0/1) traits for each lactation. Threshold sire models were used to model claw disorders, whereas the feet and leg conformation traits were described by linear sire models. Three multivariate analyses were performed, each including the 5 feet and leg conformation traits and 1 of the 3 claw disorders at a time. Posterior means of heritability of liability of claw disorders ranged from 0.10 to 0.20 and heritabilities of feet and leg conformation traits ranged from 0.04 to 0.11. Posterior standard deviation of heritability was ≤0.01 for all traits. Genetic correlations between claw disorders and feet and leg conformation traits were all low or moderate, except between corkscrew claw and hoof quality (-0.86), which are supposed to measure the same trait. The genetic correlations between rear leg rear view (new) and infectious claw disorders (-0.20) and laminitis-related claw disorders (0.26), and between hoof quality and laminitis-related claw disorders (-0.33) were moderate. Eight of the 15 genetic correlations between claw disorders and feet and leg conformation traits had 0

Stressful working conditions and poor self-rated health among financial services employees

Directory of Open Access Journals (Sweden)

Luiz Sérgio Silva

2012-06-01

Full Text Available OBJECTIVE: To assess the association between exposure to adverse psychosocial working conditions and poor self-rated health among bank employees. METHODS: A cross-sectional study including a sample of 2,054 employees of a government bank was conducted in 2008. Self-rated health was assessed by a single question: "In general, would you say your health is (...." Exposure to adverse psychosocial working conditions was evaluated by the effort-reward imbalance model and the demand-control model. Information on other independent variables was obtained through a self-administered semi-structured questionnaire. A multiple logistic regression analysis was performed and odds ratio calculated to assess independent associations between adverse psychosocial working conditions and poor self-rated health. RESULTS: The overall prevalence of poor self-rated health was 9%, with no significant gender difference. Exposure to high demand and low control environment at work was associated with poor self-rated health. Employees with high effort-reward imbalance and overcommitment also reported poor self-rated health, with a dose-response relationship. Social support at work was inversely related to poor self-rated health, with a dose-response relationship. CONCLUSIONS: Exposure to adverse psychosocial work factors assessed based on the effort-reward imbalance model and the demand-control model is independently associated with poor self-rated health among the workers studied.

Effects of combined high intensity arm and leg training on performance and cardio-respiratory measures.

Science.gov (United States)

Zinner, Christoph; Sperlich, Billy; Born, Dennis-Peter; Michels, Guido

2017-01-01

The purpose of this study was to investigate the effects of combined arm and leg high-intensity low-volume interval training (HIITarm+leg) on maximal oxygen uptake, myocardial measures (i.e. stroke volume, cardiac output, ejection fraction), Tissue Oxygenation Index (TOI) of the vastus lateralis and triceps brachii, as well as power output in comparison to leg HIIT (HIITleg) only. The 20 healthy, male and female volunteers completed six sessions of either HIITleg on a cycle ergometer or HIITarm+leg on an arm and leg cycle ergometer. During pre- and post-testing, the volunteers completed a submaximal and incremental test to exhaustion on a cycle ergometer. Magnitude based interference revealed likely to very likely beneficial effects for HIITarm+leg compared to HIITleg in maximal oxygen uptake, cardiac measures as well peak power output. The TOI following HIITarm+leg demonstrated likely to very likely increased oxygenation in the triceps brachii or the vastus lateralis when compared to HIITleg. The results suggest that six sessions of HIITarm+leg may likely to very likely improve maximal oxygen uptake, some inotropy-related cardiac measures with improved tissue oxygenation of the triceps brachii and vastus lateralis muscles resulting in greater leg peak power output.

Gait Planning Research for an Electrically Driven Large-Load-Ratio Six-Legged Robot

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Hong-Chao Zhuang

2017-03-01

Full Text Available Gait planning is an important basis for the walking of a legged robot. To improve the walking stability of multi-legged robots and to reduce the impact force between the foot and the ground, gait planning strategies are presented for an electrically driven large-load-ratio six-legged robot. First, the configuration and walking gait of the electrically driven large-load-ratio six-legged robot are designed. The higher-stable swing sequences of legs and typical walking modes are respectively obtained. Based on the Denavit–Hartenberg (D–H method, the analyses of the forward and inverse kinematics are implemented. The mathematical models of the articulated rotation angles are respectively established. In view of the buffer device installed at the end of shin to decrease the impact force between the foot and the ground, an initial lift height of the leg is brought into gait planning when the support phase changes into the transfer phase. The mathematical models of foot trajectories are established. Finally, a prototype of the electrically driven large-load-ratio six-legged robot is developed. The experiments of the prototype are carried out regarding the aspects of the walking speed and surmounting obstacle. Then, the reasonableness of gait planning is verified based on the experimental results. The proposed strategies of gait planning lay the foundation for effectively reducing the foot–ground impact force and can provide a reference for other large-load-ratio multi-legged robots.

Leg og læring

DEFF Research Database (Denmark)

Pedersen, Annette

2008-01-01

Leg synes at have et potentiale som metode til at fremme læring. Men hvordan? Legen har en vis grad af parallelitet med den virkelige verden i dens interaktive og relationelle strukturer. Det bliver muligt at finde nye meninger i interaktioner, som refererer til vante interaktionsformer, men...

[AA amyloidosis: a little-known complication of chronic leg ulcer].

Science.gov (United States)

Waton, J; Fays-Michel, S; Chandeclerc, M L; Corby, S; Cuny, J F; Barbaud, A; Schmutz, J-L

2008-02-01

AA amyloidosis, secondary to inflammatory chronic diseases like rheumatoid arthritis, is often complicated by renal failure. Chronic inflammatory dermatoses constitute rare causes of AA amyloidosis. We describe two cases of AA amyloidosis discovered after renal failure in patients presenting leg ulcers for several years. AL amyloidosis was suspected in both cases because of a history of monoclonal gammopathy in one patient and of plasmocytoma in the other. The diagnosis of AA amyloidosis was confirmed on renal histology through the detection of AA antibodies in amyloid deposits. No extrarenal amyloidosis was seen in either patient and there were no inflammatory diseases other than chronic leg ulcers. AA amyloidosis is caused by serum amyloid protein A (SAA), a reactive inflammatory protein. AA amyloidosis is thus caused by chronic inflammatory diseases, but only rarely by cutaneous inflammatory diseases. To our knowledge, the literature contains only seven other published cases of AA amyloidosis secondary to chronic leg ulcers. A review of the literature does not indicate whether cure of ulcers has any effect on the accompanying renal failure. We imagine that AA amyloidosis secondary to leg ulcer is in fact under-diagnosed. However, since the first specific treatment for AA amyloidosis is currently being evaluated by the Food and Drug Administration, it is essential that this serious complication of chronic leg ulcers be widely recognised.

The Association between Long Working Hours and Self-Rated Health

Science.gov (United States)

2014-01-01

Objectives This study was conducted to determine the number of hours worked per week by full-time wage workers by using the data of the Korean Labor and Income Panel Study (KLIPS), which represents the domestic urban area household, and to determine the association between weekly working hours and the level of self-rated health. Methods We used data from the 11th KLIPS conducted in 2008. The subjects of this study were 3,699 full-time wage workers between the ages of 25 and 64 years. The association between weekly working hours and self-rated health was analyzed considering socio-demographic characteristics, work environment, and health-related behaviors. Results Among the workers, 29.7% worked less than 40 hours per week; 39.7%, more than 40 to 52 hours; 19.7%, more than 52 to 60 hours; and 10.9%, more than 60 hours per week. After controlling for socio-demographic variables, work environment-related variables, and health-related behavior variables, the odds ratio (OR) for poor self-rated health for the group working more than 40 hours and up to 52 hours was calculated to be 1.06 (95% confidence interval (CI), 0.89-1.27) when the group working less than 40 hours per week was considered the reference. The OR for the group working more than 60 hours was 1.42 (95% CI, 1.10-1.83) and that for the group working more than 52 hours and up to 60 hours was 1.07 (95% CI, 0.86-1.33). After stratification by gender and tenure, the OR of the female workers group and that of the group with a tenure of more than 1 year were found to be significantly higher than those of the other groups. Conclusions This study showed that workers working more than 60 hours per week have a significantly higher risk of poor self-rated health than workers working less than 40 hours per week. This effect was more obvious for the female workers group and the group with a tenure of more than 1 year. In the future, longitudinal studies may be needed to determine the association between long working

The Association between Long Working Hours and Self-Rated Health.

Science.gov (United States)

Song, Jun-Taek; Lee, Goeun; Kwon, Jongho; Park, Jung-Woo; Choi, Hyunrim; Lim, Sinye

2014-01-20

This study was conducted to determine the number of hours worked per week by full-time wage workers by using the data of the Korean Labor and Income Panel Study (KLIPS), which represents the domestic urban area household, and to determine the association between weekly working hours and the level of self-rated health. We used data from the 11th KLIPS conducted in 2008. The subjects of this study were 3,699 full-time wage workers between the ages of 25 and 64 years. The association between weekly working hours and self-rated health was analyzed considering socio-demographic characteristics, work environment, and health-related behaviors. Among the workers, 29.7% worked less than 40 hours per week; 39.7%, more than 40 to 52 hours; 19.7%, more than 52 to 60 hours; and 10.9%, more than 60 hours per week. After controlling for socio-demographic variables, work environment-related variables, and health-related behavior variables, the odds ratio (OR) for poor self-rated health for the group working more than 40 hours and up to 52 hours was calculated to be 1.06 (95% confidence interval (CI), 0.89-1.27) when the group working less than 40 hours per week was considered the reference. The OR for the group working more than 60 hours was 1.42 (95% CI, 1.10-1.83) and that for the group working more than 52 hours and up to 60 hours was 1.07 (95% CI, 0.86-1.33). After stratification by gender and tenure, the OR of the female workers group and that of the group with a tenure of more than 1 year were found to be significantly higher than those of the other groups. This study showed that workers working more than 60 hours per week have a significantly higher risk of poor self-rated health than workers working less than 40 hours per week. This effect was more obvious for the female workers group and the group with a tenure of more than 1 year. In the future, longitudinal studies may be needed to determine the association between long working hours and various health effects in Korean

Pictorial essay: Ultrasonography in 'tennis leg'.

Science.gov (United States)

Shah, Jeshil R; Shah, Bipin R; Shah, Ankit B

2010-11-01

Tennis leg is caused by a rupture of the medial head of the gastrocnemius muscle, usually at its distal musculotendinous junction region. However, tears in this muscle and its tendon are also included under the term 'tennis leg'. It is seen regularly in practice and is an important cause of a painful calf. The common USG findings include: disruption of the pinnate pattern of the distal medial gastrocnemius, usually near the junction of the triceps surae (which is the echogenic line between the gastrocnemius, the soleus, and the plantaris muscles), fluid tracking along the fascia, adjacent hematoma, and intramuscular tears as well as hematomas. USG is useful for confirming the diagnosis, excluding other causes of a painful calf, for assessing the severity of the disease, and in follow-up.

Hox gene expression leads to differential hind leg development between honeybee castes.

Science.gov (United States)

Bomtorin, Ana Durvalina; Barchuk, Angel Roberto; Moda, Livia Maria; Simoes, Zila Luz Paulino

2012-01-01

Beyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens this structure is absent. Although the morphological differences are well characterized, the genetic inputs driving the development of this alternative morphology remain unknown. Leg phenotype determination takes place between the fourth and fifth larval instar and herein we show that the morphogenesis is completed at brown-eyed pupa. Using results from the hybridization of whole genome-based oligonucleotide arrays with RNA samples from hind leg imaginal discs of pre-pupal honeybees of both castes we present a list of 200 differentially expressed genes. Notably, there are castes preferentially expressed cuticular protein genes and members of the P450 family. We also provide results of qPCR analyses determining the developmental transcription profiles of eight selected genes, including abdominal-A, distal-less and ultrabithorax (Ubx), whose roles in leg development have been previously demonstrated in other insect models. Ubx expression in workers hind leg is approximately 25 times higher than in queens. Finally, immunohistochemistry assays show that Ubx localization during hind leg development resembles the bristles localization in the tibia/basitarsus of the adult legs in both castes. Our data strongly indicate that the development of the hind legs diphenism characteristic of this corbiculate species is driven by a set of caste-preferentially expressed genes, such as those encoding cuticular protein genes, P450 and Hox proteins, in response to the naturally different diets offered to honeybees during the larval period.

ESR modes in a Strong-Leg Ladder in the Tomonaga-Luttinger Liquid Phase

Science.gov (United States)

Zvyagin, S.; Ozerov, M.; Maksymenko, M.; Wosnitza, J.; Honecker, A.; Landee, C. P.; Turnbull, M.; Furuya, S. C.; Giamarchi, T.

Magnetic excitations in the strong-leg quantum spin ladder compound (C7H10N)2CuBr4 (known as DIMPY) in the field-induced Tomonaga-Luttinger spin liquid phase are studied by means of high-field electron spin resonance (ESR) spectroscopy. The presence of a gapped ESR mode with unusual non-linear frequency-field dependence is revealed experimentally. Using a combination of analytic and exact diagonalization methods, we compute the dynamical structure factor and identify this mode with longitudinal excitations in the antisymmetric channel. We argue that these excitations constitute a fingerprint of the spin dynamics in a strong-leg spin-1/2 Heisenberg antiferromagnetic ladder and owe its ESR observability to the uniform Dzyaloshinskii-Moriya interaction. This work was partially supported by the DFG and Helmholtz Gemeinschaft (Germany), Swiss SNF under Division II, and ERC synergy UQUAM project. We acknowledge the support of the HLD at HZDR, member of the European Magnetic Field Laboratory (EMFL).

Low molecular weight heparin for prevention of venous thromboembolism in patients with lower-leg immobilization.

Science.gov (United States)

Testroote, Mark; Stigter, Willem A H; Janssen, Loes; Janzing, Heinrich M J

2014-04-25

Immobilization of the lower leg is associated with venous thromboembolism (VTE). Low molecular weight heparin (LMWH) is an anticoagulant treatment which might be used in adult patients with lower-leg immobilization to prevent deep venous thrombosis (DVT) and its complications. This is an update of the review first published in 2008. To assess the effectiveness of low molecular weight heparin for the prevention of venous thromboembolism in patients with lower-leg immobilization in an ambulant setting. For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched June 2013) and CENTRAL (2013, Issue 5). Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that described thromboprophylaxis by means of LMWH compared with no prophylaxis or placebo in adult patients with lower-leg immobilization. Immobilization was by means of a plaster cast or brace. Two authors independently assessed trial quality and extracted data. The review authors contacted the trial authors for additional information if required. Statistical analysis was carried out using Review Manager (RevMan 5). We included six RCTs fulfilling the above criteria with a total of 1490 patients. We found an incidence of VTE ranging from 4.3% to 40% in patients who had a leg injury that had been immobilized in a plaster cast or a brace for at least one week and who received no prophylaxis, or placebo. This number was significantly lower in patients who received daily subcutaneous injections of LMWH during immobilization (event rates ranging from 0% to 37%; odds ratio (OR) 0.49; fixed 95% confidence interval (CI) 0.34 to 0.72; with minimal evidence of heterogeneity with an I(2) of 20%, P = 0. 29). Comparable results were seen in the following subcategories: operated patients, conservatively treated patients, patients with fractures, patients with soft-tissue injuries, patients with proximal thrombosis, patients with

Hemodynamic effect and safety of intermittent sequential pneumatic compression leg sleeves in patients with congestive heart failure.

Science.gov (United States)

Bickel, Amitai; Shturman, Alexander; Sergeiev, Michael; Ivry, Shimon; Eitan, Arieh; Atar, Shaul

2014-10-01

Pneumatic leg sleeves are widely used after prolonged operations for prevention of venous stasis. In healthy volunteers they increase cardiac function. We evaluated the hemodynamic effects and safety of intermittent sequential pneumatic compression (ISPC) leg sleeves in patients with chronic congestive heart failure (CHF). We studied 19 patients with systolic left ventricular dysfunction and CHF. ISPC leg sleeves, each with 10 air cells, were operated by a computerized compressor, exerting 2 cycles/min. Hemodynamic and echocardiographic parameters were measured before, during, and after ISPC activation. The baseline mean left ventricular ejection fraction was 29 ± 9.2%, median 32%, range 10%-40%. Cardiac output (from 4.26 to 4.83 L/min; P = .008) and stroke volume (from 56.1 to 63.5 mL; P = .029) increased significantly after ISPC activation, without a reciprocal increase in heart rate, and declined after sleeve deactivation. Systemic vascular resistance (SVR) decreased significantly (from 1,520 to 1,216 dyne-s/cm5; P = .0005), and remained lower than the baseline level throughout the study. There was no detrimental effect on diastolic function and no adverse clinical events, despite increased pulmonary venous return. ISPC leg sleeves in patients with chronic CHF do not exacerbate symptoms and transiently improve cardiac output through an increase in stroke volume and a reduction in SVR. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of work stress on work-related rumination, restful sleep, and nocturnal heart rate variability experienced on workdays and weekends.

Science.gov (United States)

Vahle-Hinz, Tim; Bamberg, Eva; Dettmers, Jan; Friedrich, Niklas; Keller, Monika

2014-04-01

The present study reports the lagged effects of work stress on work-related rumination, restful sleep, and nocturnal heart rate variability experienced during both workdays and weekends. Fifty employees participated in a diary study. Multilevel and regression analyses revealed a significant relationship between work stress measured at the end of a workday, work-related rumination measured during the evening, and restful sleep measured the following morning. Work stress, measured as the mean of 2 consecutive workdays, was substantially but not significantly related to restful sleep on weekends. Work stress was unrelated to nocturnal heart rate variability. Work-related rumination was related to restful sleep on weekends but not on workdays. Additionally, work-related rumination on weekends was positively related to nocturnal heart rate variability during the night between Saturday and Sunday. No mediation effects of work stress on restful sleep or nocturnal heart rate variability via work-related rumination were confirmed.

A systematic review on the impact of leg ulceration on patients' quality of life

Directory of Open Access Journals (Sweden)

Rieger Monika A

2007-07-01

Full Text Available Abstract Background A systematic review was conducted to analyse journal articles that describe or measure the impact of leg ulceration on patients' quality of life (QoL in order to improve the content of an educational programme that aims to enhance self-care agency in leg ulcer patients. Method Original articles published in English and German between 1990 and 2006 were included if the findings were analysed at the level of patients. Articles were excluded if (1 they investigated the impact of specific treatments or settings on QoL or (2 focused mainly on arterial ulcers or diabetic foot ulcers. Results Twenty-four original research articles met the inclusion criteria; 11 studies used a quantitative, 11 studies a qualitative, and 2 used a mixed method approach. The findings were collapsed into 5 core domains. Quantitative studies commonly investigated the parameters of pain, sleep, social isolation, and physical mobility. Patients had significantly more pain, more restrictions regarding social functioning, less vitality, and limitations with respect to emotional roles compared to the respective controls. Other problem areas identified were restrictions in work capacity, recreation, social interaction, psychological well-being, as well as problems caused by treatment regimes. Inconclusive results were obtained regarding pain intensity, physical restrictions, and gender effects. Limitations Numerous original studies neither undertook a differentiation of participants by ulcer aetiology nor did they analyse the results according to gender differences. Conclusion As leg ulceration has an impact on QoL, national guidelines on the treatment of leg ulceration need to more specifically address these far-ranging effects identified in this review.

GABAergic inhibition of leg motoneurons is required for normal walking behavior in freely moving Drosophila.

Science.gov (United States)

Gowda, Swetha B M; Paranjpe, Pushkar D; Reddy, O Venkateswara; Thiagarajan, Devasena; Palliyil, Sudhir; Reichert, Heinrich; VijayRaghavan, K

2018-02-27

Walking is a complex rhythmic locomotor behavior generated by sequential and periodical contraction of muscles essential for coordinated control of movements of legs and leg joints. Studies of walking in vertebrates and invertebrates have revealed that premotor neural circuitry generates a basic rhythmic pattern that is sculpted by sensory feedback and ultimately controls the amplitude and phase of the motor output to leg muscles. However, the identity and functional roles of the premotor interneurons that directly control leg motoneuron activity are poorly understood. Here we take advantage of the powerful genetic methodology available in Drosophila to investigate the role of premotor inhibition in walking by genetically suppressing inhibitory input to leg motoneurons. For this, we have developed an algorithm for automated analysis of leg motion to characterize the walking parameters of wild-type flies from high-speed video recordings. Further, we use genetic reagents for targeted RNAi knockdown of inhibitory neurotransmitter receptors in leg motoneurons together with quantitative analysis of resulting changes in leg movement parameters in freely walking Drosophila Our findings indicate that targeted down-regulation of the GABA A receptor Rdl (Resistance to Dieldrin) in leg motoneurons results in a dramatic reduction of walking speed and step length without the loss of general leg coordination during locomotion. Genetically restricting the knockdown to the adult stage and subsets of motoneurons yields qualitatively identical results. Taken together, these findings identify GABAergic premotor inhibition of motoneurons as an important determinant of correctly coordinated leg movements and speed of walking in freely behaving Drosophila . Copyright © 2018 the Author(s). Published by PNAS.

Leg ulcer assessment techniques in a remote rural area.

Science.gov (United States)

Graham, Julia

Community-based leg ulcer clinics are a cost-effective and efficient way of managing patients with leg ulcers in the community (Blair et al, 1988; Moffatt and Oldroyd, 1994). According to the Scottish Clinical Standards for Vascular Services (NHS Quality Improvement Scotland, 2003): 'It is essential that all vascular patients are seen by a nurse with vascular expertise, who is able to provide information, support and health promotion advice'.

Compression therapy in patients with venous leg ulcers.

Science.gov (United States)

Dissemond, Joachim; Assenheimer, Bernd; Bültemann, Anke; Gerber, Veronika; Gretener, Silvia; Kohler-von Siebenthal, Elisabeth; Koller, Sonja; Kröger, Knut; Kurz, Peter; Läuchli, Severin; Münter, Christian; Panfil, Eva-Maria; Probst, Sebastian; Protz, Kerstin; Riepe, Gunnar; Strohal, Robert; Traber, Jürg; Partsch, Hugo

2016-11-01

Wund-D.A.CH. is the umbrella organization of the various wound care societies in German-speaking countries. The present consensus paper on practical aspects pertinent to compression therapy in patients with venous leg ulcers was developed by experts from Germany, Austria, and Switzerland. In Europe, venous leg ulcers rank among the most common causes of chronic wounds. Apart from conservative and interventional wound and vein treatment, compression therapy represents the basis of all other therapeutic strategies. To that end, there are currently a wide variety of materials and systems available. While especially short-stretch bandages or multicomponent systems should be used in the initial decongestion phase, ulcer stocking systems are recommended for the subsequent maintenance phase. Another - to date, far less common - alternative are adaptive Velcro bandage systems. Medical compression stockings have proven particularly beneficial in the prevention of ulcer recurrence. The large number of treatment options currently available enables therapists to develop therapeutic concepts geared towards their patients' individual needs and abilities, thus resulting in good acceptance and adherence. Compression therapy plays a crucial role in the treatment of patients with venous leg ulcers. In recent years, a number of different treatment options have become available, their use and application differing among German-speaking countries. The present expert consensus is therefore meant to outline concrete recommendations for routine implementation of compression therapy in patients with venous leg ulcers. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Work Rate during Self-paced Exercise is not Mediated by the Rate of Heat Storage.

Science.gov (United States)

Friesen, Brian J; Périard, Julien D; Poirier, Martin P; Lauzon, Martin; Blondin, Denis P; Haman, Francois; Kenny, Glen P

2018-01-01

To date, there have been mixed findings on whether greater anticipatory reductions in self-paced exercise intensity in the heat are mediated by early differences in rate of body heat storage. The disparity may be due to an inability to accurately measure minute-to-minute changes in whole-body heat loss. Thus, we evaluated whether early differences in rate of heat storage can mediate exercise intensity during self-paced cycling at a fixed rate of perceived exertion (RPE of 16; hard-to-very-hard work effort) in COOL (15°C), NORMAL (25°C), and HOT (35°C) ambient conditions. On separate days, nine endurance-trained cyclists exercised in COOL, NORMAL, and HOT conditions at a fixed RPE until work rate (measured after first 5 min of exercise) decreased to 70% of starting values. Whole-body heat loss and metabolic heat production were measured by direct and indirect calorimetry, respectively. Total exercise time was shorter in HOT (57 ± 20 min) relative to both NORMAL (72 ± 23 min, P = 0.004) and COOL (70 ± 26 min, P = 0.045). Starting work rate was lower in HOT (153 ± 31 W) compared with NORMAL (166 ± 27 W, P = 0.024) and COOL (170 ± 33 W, P = 0.037). Rate of heat storage was similar between conditions during the first 4 min of exercise (all P > 0.05). Thereafter, rate of heat storage was lower in HOT relative to NORMAL and COOL until 30 min of exercise (last common time-point between conditions; all P exercise. No differences were measured at end exercise. We show that rate of heat storage does not mediate exercise intensity during self-paced exercise at a fixed RPE in cool to hot ambient conditions.

Association of restless legs syndrome, pain, and mood disorders in Parkinson's disease.

Science.gov (United States)

Rana, Abdul Qayyum; Qureshi, Abdul Rehman M; Rahman, Labiba; Jesudasan, Ajantha; Hafez, Kevin K; Rana, Mohammad A

2016-01-01

The objectives of the study were to analyze the association between Parkinson's disease and restless legs syndrome, and to explore the relationship between mood disorder comorbidity (anxiety and depression), pain, and restless legs syndrome. This study included 123 Parkinson's disease patients and 123 non-Parkinson's disease patients matched for age and gender, and evaluated for anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence. This was performed using semi-structured interviews and a neurological examination through the restless legs syndrome diagnostic criteria and the following inventories; Hospital Anxiety and Depression Scale, Brief Pain Inventory, and Pain Disability Index. Parkinson's disease patients had significantly greater anxiety severity, depression severity, pain severity, pain interference, pain disability, and restless legs syndrome prevalence in comparison to controls. In addition, Parkinson's disease patients' comorbid for anxiety and depression had significantly greater pain severity, pain interference, and pain disability, but not RLS prevalence, in comparison to Parkinson's disease only, Parkinson's disease anxiety, and Parkinson's disease depression patients. Pain interference, pain severity, and pain disability is greater among Parkinson's disease patients with anxiety and depression, in comparison to Parkinson's disease patients without anxiety and depression. On the contrary, the prevalence of restless legs syndrome was not found to be relevant.

Numerical simulation of thermal stratification in cold legs by using openFOAM

International Nuclear Information System (INIS)

Cai, Jiejin; Watanabe, Tadashi

2010-01-01

During a small-break loss-of-coolant accident in pressurized water reactors (PWRs), emergency core cooling system (ECCS) is actuated and cold water is injected into cold legs. Insufficient mixing of injected cold water and hot primary coolant results in thermal stratification, which is a matter of concern for evaluation of pressurized thermal shock (PTS) in view of aging and life extension of nuclear power plants. In this study, an open source CFD software, OpenFOAM, is used to simulate mixing and thermal stratification in the cold leg of ROSA/LSTF, which is the largest thermal-hydraulic integral test facility simulating PWR. One of the cold-leg is numerically simulated from the outlet of primary coolant pump to the inlet of downcomer. ECCS water is injected from injection nozzle connected at the top of the cold leg into the steady-state natural circulation flow under high-pressure and high-temperature conditions. The temperature distribution in the cold leg is compared with experimental and FLUENT's results. Effects of turbulent flow models and secondary flow due to the elbow section of the cold leg are discussed for the case with the single-phase natural circulation. Injection into a two-phase stratified flow is also simulated and predictive and numerical capabilities of OpenFOAM are discussed. (author)

PERFORMANCE OF CULTURED White-leg Shrimp IN RICA Probiotic Application METHOD in PONDS AERATED WITH SUPERCHARGE BLOWER

Directory of Open Access Journals (Sweden)

Endang Susianingsih

2017-09-01

Full Text Available Several ways have been done to encounter shrimp disease affecting cultured shrimp in Indonesian ponds in the last two decades. This research was aimed to find out the effect of different application of probiotic RICA4, RICA5, and RICA3 method on survival rate and production of white-leg shrimp (Litopenaeus vannamei cultured in ponds aerated with supercharge blower. RICA probiotics are bacteria probiotics produced by the Research and Development Institute for Coastal Aquaculture, originally isolated from seaweed and sea sediment. This experiment was carried out in completely randomized design using nine 250-m2 experimental ponds stocked with 15 shrimp fries/m2. There were three treatments namely: A=alternate use of three probiotics RICA4, RICA5, and RICA3; B=combination use of three probiotics RICA4, RICA5, and RICA3; and C=control (without probiotic, each treatment with three replications and cultured with supercharge blower. Variables observed in this study were survival rate and production of the shrimp calculated at the end of experiment, total vibrio count (TBV and total plate count of common bacteria (TPC of the pond waters and sediments monitored every two weeks. The results showed that application of probiotic RICA4, RICA5, and RICA3 applied either in alteration or in combination significantly increased survival rate (P0.05 of the white-leg shrimp. TBV/TPC ratio in the control pond waters after 10-weeks culture (over than 10% was relatively dangerous for the cultured white-leg shrimp. This shows that application of probiotic could prevent the growth of Vibrio spp in the cultured shrimp pond water.

Scale dependence of rock friction at high work rate.

Science.gov (United States)

Yamashita, Futoshi; Fukuyama, Eiichi; Mizoguchi, Kazuo; Takizawa, Shigeru; Xu, Shiqing; Kawakata, Hironori

2015-12-10

Determination of the frictional properties of rocks is crucial for an understanding of earthquake mechanics, because most earthquakes are caused by frictional sliding along faults. Prior studies using rotary shear apparatus revealed a marked decrease in frictional strength, which can cause a large stress drop and strong shaking, with increasing slip rate and increasing work rate. (The mechanical work rate per unit area equals the product of the shear stress and the slip rate.) However, those important findings were obtained in experiments using rock specimens with dimensions of only several centimetres, which are much smaller than the dimensions of a natural fault (of the order of 1,000 metres). Here we use a large-scale biaxial friction apparatus with metre-sized rock specimens to investigate scale-dependent rock friction. The experiments show that rock friction in metre-sized rock specimens starts to decrease at a work rate that is one order of magnitude smaller than that in centimetre-sized rock specimens. Mechanical, visual and material observations suggest that slip-evolved stress heterogeneity on the fault accounts for the difference. On the basis of these observations, we propose that stress-concentrated areas exist in which frictional slip produces more wear materials (gouge) than in areas outside, resulting in further stress concentrations at these areas. Shear stress on the fault is primarily sustained by stress-concentrated areas that undergo a high work rate, so those areas should weaken rapidly and cause the macroscopic frictional strength to decrease abruptly. To verify this idea, we conducted numerical simulations assuming that local friction follows the frictional properties observed on centimetre-sized rock specimens. The simulations reproduced the macroscopic frictional properties observed on the metre-sized rock specimens. Given that localized stress concentrations commonly occur naturally, our results suggest that a natural fault may lose its

Objective assessment of leg edema using ultrasonography with a gel pad

Science.gov (United States)

Iuchi, Terumi; Tsuchiya, Sayumi; Ohno, Naoki; Dai, Misako; Matsumoto, Masaru; Ogai, Kazuhiro; Sato, Aya; Sawazaki, Takuto; Miyati, Tosiaki; Tanaka, Shinobu; Sugama, Junko

2017-01-01

Ultrasonography (US) is useful for visual detection of edematous tissues to assess subcutaneous echogenicity. However, visualization of subcutaneous echogenicity is interpreted differently among operators because the evaluation is subjective and individual operators have unique knowledge. This study objectively assessed leg edema using US with a gel pad including fat for normalization of echogenicity in subcutaneous tissue. Five younger adults and four elderly people with leg edema were recruited. We compared assessments of US and limb circumference before and after the intervention of vibration to decrease edema in younger adults, and edema prior to going to sleep and reduced edema in the early morning in elderly people. These assessments were performed twice in elderly people by three operators and reliability, interrater differences, and bias were assessed. For US assessment, echogenicity in subcutaneous tissue was normalized to that of the gel pad by dividing the mean echogenicity of subcutaneous tissue by the mean echogenicity of the gel pad. In younger adults, the normalized subcutaneous echogenicity before the intervention was significantly higher than that after the intervention. In elderly people, echogenicity indicating edema was significantly higher than that after edema reduction. Edema was detected with accuracy rates of 76.9% in younger adults and 75.0% in elderly people. Meanwhile, limb circumference could be used to detect edema in 50.0% of healthy adults and 87.8% of elderly people. The intra-reliability was excellent (intraclass correlation coefficient > 0.9, p 0.7, p edema with high reliability. Therefore, this method has the potential to become a new gold standard for objective assessment of leg edema in clinical practice. PMID:28792959

Myonecrosis in the leg caused by Salmonella enteritidis

DEFF Research Database (Denmark)

Jørring, S; Kolmos, H J; Klareskov, B

1994-01-01

Five weeks after an episode of gastroenteritis, a 65-year-old diabetic male developed an extensive myonecrosis, with gas production in the left leg caused by Salmonella enteritidis. The patient was treated with surgical revision and antibiotics. To our knowledge, this is the first case of myonecr......Five weeks after an episode of gastroenteritis, a 65-year-old diabetic male developed an extensive myonecrosis, with gas production in the left leg caused by Salmonella enteritidis. The patient was treated with surgical revision and antibiotics. To our knowledge, this is the first case...

Experimental characterisation of the interfacial structure during counter-current flow limitation in a model of the hot leg of a PWR

Energy Technology Data Exchange (ETDEWEB)

Vallee, C., E-mail: c.vallee@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Inst. of Safety Research, Dresden (Germany); Nariai, T.; Futatsugi, T.; Tomiyama, A., E-mail: nariai@cfrg.scitec.kobe-u.ac.jp, E-mail: futatsugi@cfrg.scitec.kobe-u.ac.jp, E-mail: tomiyama@mech.kobe-u.ac.jp [Kobe Univ., Graduate School of Engineering, Kobe (Japan); Lucas, D., E-mail: d.lucas@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Inst. of Safety Research, Dresden (Germany); Murase, M., E-mail: murase@inss.co.jp [Inst. of Nuclear Safety System, Inc. (INSS), Fukui (Japan)

2011-07-01

In order to investigate the two-phase flow behaviour during counter-current flow limitation in the hot leg of a pressurised water reactor, dedicated experiments were performed in a scaled down model of Kobe University. The structure of the interface was observed from the side of the channel test section using a high-speed video camera. An algorithm was developed to recognise the stratified interface in the camera frames after background subtraction. The evolution of the water level along the hot leg is analysed in function of the liquid and gas flow rates. (author)

Effect of Adding the White Legged Shrimp (Penaeus vannamei) on Growth and Survival of Tiger Shrimp (Penaeus monodon) in Intensive Farming

OpenAIRE

. Tarsim

2007-01-01

This experiment was carried out in the framework of a project to develop a viable shrimp polyculture technology under intensive farming. The objectives were to assess the effect of adding white legged shrimp (Penaeus vannamei) on growth and survival of tiger shrimp (Penaeus monodon) in intensive Farming. Tiger shrimp were stocked in 2800-3400 m2 earthen ponds at 40 individuals/m2 and reared for 133 days. White legged shrimp added at 70 day at 8±2 individuals/m2. Growth rate and total yield af...

Dynamically Stable Legged Locomotion

Science.gov (United States)

1981-11-30

the laboratory. Harry Asada, Wayne Book, Nancy Cornelius, Sesh Murthy and Ivan Sutherland read various drafts of this report, for which we are...particularly helpful in providing an atmosphere where things could get started. Craig Fields and Clint Kelly deserve special credit for letting the idea of...legged technology capture their imaginations, even before we could show them tangible results. We are especially indebted to Ivan Sutherland for his

Balanced gait generations of a two-legged robot on sloping surface

Indian Academy of Sciences (India)

legged robot moving up and down through the sloping surface is presented. The gait of the lower links during locomotion is obtained after assuming suitable trajectories for the swing leg and hip joint. The trunk motion is initially generated based on ...

Near infrared spectroscopy for controlling the quality of distal leg perfusion in remote access cardiopulmonary bypass.

Science.gov (United States)

Schachner, Thomas; Bonaros, Nikolaos; Bonatti, Johannes; Kolbitsch, Christian

2008-12-01

The prevention of leg ischemia is necessary in all patients undergoing femoral artery cannulation for extracorporeal circulation. Near infrared spectroscopy (NIRS) is an established non-invasive method for measuring tissue oxygen saturation. Ten patients underwent robotically assisted endoscopic coronary surgery or ASD repair on the arrested heart using aortic endo-occlusion catheters. They were monitored by transcutaneous NIRS (placed on both lower legs) for quality control of distal leg perfusion during femoral access cardiopulmonary bypass. The baseline NIRS values were 61 (52-80) on the cannulated side versus 70 (53-80) on the contralateral leg (p=n.s.). During clamping of the femoral artery for installation of the remote access perfusion system the tissue oxygen saturation dropped to 38 (18-58) (p=0.001 vs baseline) while it remained stable on the contralateral leg. After successful implantation of the distal leg perfusion the NIRS values normalized to similar amounts on both legs. We conclude that transcutaneous NIRS of the lower legs might be a useful non-invasive tool for monitoring leg perfusion in patients undergoing extracorporeal circulation via the femoral vessels.

Genetic association between leg conformation in young pigs and sow reproduction

DEFF Research Database (Denmark)

Le, Thu Hong; Nilsson, Katja; Norberg, Elise

2015-01-01

Lameness is an issue of concern in pig production due both to animal welfare and to economical aspects. Lame sows are believed to suffer from pain and stress which is reported to have a negative influence on reproduction. Leg conformation and locomotion traits in young animals are associated...... with the risk of lameness at higher age. The purpose of this study was to estimate the genetic parameters of leg conformation traits recorded at performance testing (around 5 months of age) and their genetic correlations with reproduction traits. Information on leg conformation traits from 123,307 pigs scored...... and on reproduction traits from 22,204 litters in the first and second parity from Swedish Yorkshire nucleus herds were available for genetic analysis. Eight conformation and locomotion traits, coming from the old or the new scoring system in Sweden, included old movement, old overall leg score, new movement, new...

Normalized knee-extension strength or leg-press power after fast-track total knee arthroplasty

DEFF Research Database (Denmark)

Aalund, Peter K; Larsen, Kristian; Hansen, Torben Bæk

2013-01-01

OBJECTIVE: (s): To investigate which of the two muscle-impairment measures for the operated leg, normalized knee extension strength or leg press power, is more closely associated to performance-based and self-reported measures of function shortly following total knee arthroplasty (TKA). DESIGN...... and dynamic leg presses to determine their body-mass normalized knee extension strength and leg press power, respectively. The 10-m fast speed walking and 30-s chair stand tests were used to determine performance-based function, while the Western Ontario McMaster University Osteoarthritis Index (WOMAC......) and Oxford Knee scores were used to determine self-reported function. RESULTS: Normalized leg press power was more closely associated to both performance-based (r=.82, P...

The Verbal Rating Scale Is Reliable for Assessment of Postoperative Pain in Hip Fracture Patients

DEFF Research Database (Denmark)

Bech, R. D.; Lauritsen, J.; Ovesen, O.

2015-01-01

Background. Hip fracture patients represent a challenge to pain rating due to the high prevalence of cognitive impairment. Methods. Patients prospectively rated pain on the VRS. Furthermore, patients described the changes in pain after raising their leg, with one of five descriptors. Agreement...... between paired measures on the VRS at rest and by passive straight leg raise with a one-minute interval between ratings at rest and three-minute interval for straight leg raise was expressed by kappa coefficients. Reliability of this assessment of pain using the VRS was compared to the validity...... weighted kappa coefficients ranged from 0.68 (95% CI = 0.59-0.77) at leg raise to 0.75 (95% CI = 0.65-0.85) at rest. Unweighted kappa coefficients of agreement in recalled pain compared to agreement of paired VRS scores ranged from 0.57 (95% CI = 0.49-0.65) to 0.36 (95% CI = 0.31-0.41). Interpretation...

Leg loss in Lutzomyia longipalpis (Diptera: Psychodidae) due to pyrethroid exposure: Toxic effect or defense by autotomy?

Science.gov (United States)

Santamaría, E; Cabrera, O L; Avendaño, J; Pardo, R H

2016-01-01

Phlebotomine sandflies lose their legs after exposure to pyrethroids. In some insects leg loss helps to defend them from intoxication and predation, a phenomenon known as autotomy. A field observation has shown that sandflies that have lost some legs are still able to blood-feed. The aims of the study were to determine whether leg loss in sandflies, after exposure to deltamethrin, is due to autotomy and to establish the effect of the leg loss on blood-feeding. Two experiments were carried out with Lutzomyia longipalpis: (i) Females were individually exposed to a sublethal time of deltamethrin and mortality and the number of leg loss were recorded; and (ii) Groups of females with complete legs or with 1-3 legs lost due to pyrethroid exposure were offered a blood meal and percentages of blood-fed and fully-fed females were recorded. Most females lost a median of 1 leg within 1-48 h post-exposure to deltamethrin. Mortality (after 24 h) was significantly higher for exposed females with lost legs (31.1%), compared to exposed females with complete legs (7.3%), and there were no differences in mortality between females with complete legs and the control (unexposed females). There were no differences between the three treatments in the percentages of blood-fed and fully-fed females. Leg loss in sandflies is a toxic effect of pyrethroids and there was no evidence of autotomy. The loss of up to three legs after exposure to pyrethroids does not affect blood-feeding behaviour in laboratory and probably also in wild conditions.

Conflicts at work--the relationship with workplace factors, work characteristics and self-rated health.

Science.gov (United States)

Oxenstierna, Gabriel; Magnusson Hanson, Linda L; Widmark, Maria; Finnholm, Kristina; Stenfors, Cecilia; Elofsson, Stig; Theorell, Töres

2011-01-01

Few studies have considered the work environment in relation to workplace conflicts and those who have been published have included relatively few psychosocial work environment factors. Little research has been published on the consequences of workplace conflicts in terms of employee health. In this study, the statistical relationships between work and workplace characteristics on one hand and conflicts on the other hand are examined. In addition, the relationship between conflicts at work and self-rated health are described. The study population was derived from the Swedish Longitudinal Occupational Survey of Health (SLOSH) 2006; n=5,141. Among employees at workplaces with more than 20 employees (n=3,341), 1,126 (33.7%) responded that they had been involved in some type of conflict during the two years preceding the survey. Among the work and workplace characteristics studied, the following factors were independently associated with increased likelihood of ongoing conflicts: Conflicting demands, emotional demands, risk of transfer or dismissal, poor promotion prospects, high level of employee influence and good freedom of expression. Factors that decreased the likelihood of ongoing conflicts were: Good resources, good relations with management, good confidence in management, good procedural justice (fairness of decisions) and good social support. After adjustment for socioeconomic conditions the odds ratio for low self-rated health associated with ongoing conflict at work was 2.09 (1.60-2.74). The results provide a good starting point for intervention and prevention work.

Living with clipped wings—Patients’ experience of losing a leg

Directory of Open Access Journals (Sweden)

Annelise Norlyk

2013-10-01

Full Text Available This study explores the lived experience of losing a leg as described by the patients themselves post-discharge. Studies have documented that regardless of aetiology patients are faced with severe physical as well as psychosocial challenges post-amputation. However, only few studies explore in-depth the patients’ perspective on the various challenges following the loss of a leg. The study uses the phenomenological approach of Reflective Lifeworld Research (RLR. Data were collected from 24 in-depth interviews with 12 Danish patients. Data analysis was performed according to the guidelines given in RLR. The essential meaning of losing a leg is a radical and existential upheaval, which restricts patients’ lifestyle and irretrievably alters their lifeworld. Life after the operation is associated with despair, and a painful sense of loss, but also with the hope of regaining personal independence. The consequences of losing a leg gradually materialize as the patients realize how the loss of mobility limits their freedom. Patients experience the professional help as primarily directed towards physical care and rehabilitation. The findings show that the loss of a leg and, subsequently, the restricted mobility carry with them an existential dimension which refers to limitation of action space and loss of freedom experienced as an exclusion from life. Our findings demonstrate a need for complementary care and stress the importance of an increased awareness of the psychosocial and existential consequences of losing a limb.

Second-leg home advantage in the Copa Libertadores da América (2005-2015

Directory of Open Access Journals (Sweden)

Cesar Cavinato Cal Abad

2017-11-01

Full Text Available ABSTRACT 24. Aims To investigate the home advantage (HA in the Copa Libertadores da América (CLA from 2005 to 2015. Methods A naive analysis was applied considering how many times a team that played the second leg at home qualified for the next round. To verify differences between home, away and draw results, the Chi-square ( χ2 and the Full Bayesian Significance Test were applied. For the binomial variables ("Home" or "Away", the probability of second-leg knockout occurrence was calculated. Results The probability of second-leg HA varied from 27.27% to 63.64% suggesting fluctuations of second-leg HA during competitive phases (round of 16, quarterfinals, semi-finals and final matches and decision forms (full time, goals away rule or penalty-shoots. Conclusion The results counteract the common belief that there is a large advantage to playing the second match of a two-leg tie at home during all competition phases. Penalty-shots seemed to affect positively the second-leg HA. Despite the causes of second leg HA in CLA need to be better investigated, soccer coaches could to use these results to think better strategies to win your knockout matches.

Use of results of microbiological analyses for risk-based control of Listeria monocytogenes in marinated broiler legs.

Science.gov (United States)

Aarnisalo, Kaarina; Vihavainen, Elina; Rantala, Leila; Maijala, Riitta; Suihko, Maija-Liisa; Hielm, Sebastian; Tuominen, Pirkko; Ranta, Jukka; Raaska, Laura

2008-02-10

Microbial risk assessment provides a means of estimating consumer risks associated with food products. The methods can also be applied at the plant level. In this study results of microbiological analyses were used to develop a robust single plant level risk assessment. Furthermore, the prevalence and numbers of Listeria monocytogenes in marinated broiler legs in Finland were estimated. These estimates were based on information on the prevalence, numbers and genotypes of L. monocytogenes in 186 marinated broiler legs from 41 retail stores. The products were from three main Finnish producers, which produce 90% of all marinated broiler legs sold in Finland. The prevalence and numbers of L. monocytogenes were estimated by Monte Carlo simulation using WinBUGS, but the model is applicable to any software featuring standard probability distributions. The estimated mean annual number of L. monocytogenes-positive broiler legs sold in Finland was 7.2x10(6) with a 95% credible interval (CI) 6.7x10(6)-7.7x10(6). That would be 34%+/-1% of the marinated broiler legs sold in Finland. The mean number of L. monocytogenes in marinated broiler legs estimated at the sell-by-date was 2 CFU/g, with a 95% CI of 0-14 CFU/g. Producer-specific L. monocytogenes strains were recovered from the products throughout the year, which emphasizes the importance of characterizing the isolates and identifying strains that may cause problems as part of risk assessment studies. As the levels of L. monocytogenes were low, the risk of acquiring listeriosis from these products proved to be insignificant. Consequently there was no need for a thorough national level risk assessment. However, an approach using worst-case and average point estimates was applied to produce an example of single producer level risk assessment based on limited data. This assessment also indicated that the risk from these products was low. The risk-based approach presented in this work can provide estimation of public health risk

Use of ultraportable vacuum therapy systems in the treatment of venous leg ulcer.

Science.gov (United States)

Cuomo, Roberto; Nisi, Giuseppe; Grimaldi, Luca; Brandi, Cesare; D'Aniello, Carlo

2017-10-23

The high incidence of venous leg ulcers and the difficult to give a complete healing involves in an increase of costs for National Health System. Main therapies to obtain a fast healing are compressive bandages, treatment of abnormal venous flow and in-situ-strategies of wound care. Negative pressure therapy does not conventionally used, because these systems not allow the use of compression bandages. Recently the development of ultraportable devices has improved the compliance and the results. Ten patients with venous chronic ulcer on the lower extremities were recruited for this study: all patients had venous leg ulcers from at least one year. We treated the patients with autologous partial thickness skin graft and subsequently we applied NANOVA device included in compressive bandage. We used NANOVA for fourteen days and after we made traditional medications. We submitted a questionnaire to evaluate the impact of dressing and NANOVA device in the quality of life of patients. The device contributed to the formation of granulation tissue and increased the success rate of autologous skin graft without limiting mobility of patient. In addition to this, we have been able to perform compression bandages thanks to small size of this device. Eight ulcers healed within 90 days of medication. We believe that ultraportable negative pressure systems are useful devices for treatment of venous leg ulcers because them allows to realize a compressive bandage without mobility limitations.

Numerical simulation of thermal stratification in cold legs by using OpenFOAM

International Nuclear Information System (INIS)

Cai, Jiejin; Watanabe, Tadashi

2011-01-01

During a small-break loss-of-coolant accident in pressurized water reactors (PWRs), emergency core cooling system (ECCS) is actuated and cold water is injected into cold legs. Insufficient mixing of injected cold water and hot primary coolant results in thermal stratification, which is a matter of concern for evaluation of pressurized thermal shock (PTS) in view of aging and life extension of nuclear power plants. In this study, an open source CFD software, OpenFOAM, is used to simulate mixing and thermal stratification in the cold leg of ROSA/LSTF, which is the largest thermal-hydraulic integral test facility simulating PWR. One of the cold-leg is numerically simulated from the outlet of primary coolant pump to the inlet of downcomer. ECCS water is injected from injection nozzle connected at the top of the cold leg into the steady-state natural circulation flow under high-pressure and high-temperature conditions. The temperature distribution in the cold leg is compared with experimental and FLUENT's results. Effects of turbulent flow models and secondary flow due to the elbow section of the cold leg are discussed for the case with the single-phase natural circulation. Injection into a two-phase stratified flow is also simulated and predictive and numerical capabilities of OpenFOAM are discussed. (author)

A comparison and update of direct kinematic-kinetic models of leg stiffness in human running.

Science.gov (United States)

Liew, Bernard X W; Morris, Susan; Masters, Ashleigh; Netto, Kevin

2017-11-07

Direct kinematic-kinetic modelling currently represents the "Gold-standard" in leg stiffness quantification during three-dimensional (3D) motion capture experiments. However, the medial-lateral components of ground reaction force and leg length have been neglected in current leg stiffness formulations. It is unknown if accounting for all 3D would alter healthy biologic estimates of leg stiffness, compared to present direct modelling methods. This study compared running leg stiffness derived from a new method (multiplanar method) which includes all three Cartesian axes, against current methods which either only include the vertical axis (line method) or only the plane of progression (uniplanar method). Twenty healthy female runners performed shod overground running at 5.0 m/s. Three-dimensional motion capture and synchronised in-ground force plates were used to track the change in length of the leg vector (hip joint centre to centre of pressure) and resultant projected ground reaction force. Leg stiffness was expressed as dimensionless units, as a percentage of an individual's bodyweight divided by standing leg length (BW/LL). Leg stiffness using the line method was larger than the uniplanar method by 15.6%BW/LL (P method by 24.2%BW/LL (P stiffness from the uniplanar method was larger than the multiplanar method by 8.5%BW/LL (6.5 kN/m) (P stiffness estimate with the multiplanar method. Given that limb movements typically occur in 3D, the new multiplanar method provides the most complete accounting of all force and length components in leg stiffness calculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

X-Ray Exam: Femur (Upper Leg)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español X-Ray Exam: Femur (Upper Leg) KidsHealth / For Parents / X- ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

Nondrug-related aspect of treating Ekbom disease, formerly known as restless legs syndrome

Directory of Open Access Journals (Sweden)

Mitchell UH

2011-05-01

Full Text Available Ulrike H MitchellDepartment of Exercise Sciences, Brigham Young University, Provo, UT, USAAbstract: Ekbom disease (EKD, formerly known as restless legs syndrome (RLS has affected and bothered many people over the centuries. It is one of the most prevalent neurological disorders in Europe and North-America, affecting about 10% of the population. The main characteristics are the strong urge to move, accompanied or caused by uncomfortable, sometimes even distressing, paresthesia of the legs, described as a "creeping, tugging, pulling" feeling. The symptoms often become worse as the day progresses, leading to sleep disturbances or sleep deprivation, which leads to decreased alertness and daytime functions. Numerous studies have been conducted assessing the efficacy of dopaminergic drugs, opioids, and other pharmacologic agents in alleviating EKD symptoms. However, there is also a growing body of evidence demonstrating the effectiveness of nonpharmacologic treatments including life style changes, physical activity programs, pneumatic compression, massage, near-infrared light therapy, and complementary therapies. The working mechanisms behind these alternatives are diverse. Some increase blood flow to the legs, therefore reducing tissue hypoxia; some introduce an afferent counter stimulus to the cortex and with that "close the gate" for aberrant nerve stimulations; some increase dopamine and nitric oxide and therefore augment bio-available neurotransmitters; and some generate endorphins producing an analgesic effect. The advantages of these treatments compared with pharmacologic agents include less or no side effects, no danger of augmentation, and less cost.Keywords: RLS, modalities, massage, intermittent compression, NIR

Influence of “J”-Curve Spring Stiffness on Running Speeds of Segmented Legs during High-Speed Locomotion

Directory of Open Access Journals (Sweden)

Runxiao Wang

2016-01-01

Full Text Available Both the linear leg spring model and the two-segment leg model with constant spring stiffness have been broadly used as template models to investigate bouncing gaits for legged robots with compliant legs. In addition to these two models, the other stiffness leg spring models developed using inspiration from biological characteristic have the potential to improve high-speed running capacity of spring-legged robots. In this paper, we investigate the effects of “J”-curve spring stiffness inspired by biological materials on running speeds of segmented legs during high-speed locomotion. Mathematical formulation of the relationship between the virtual leg force and the virtual leg compression is established. When the SLIP model and the two-segment leg model with constant spring stiffness and with “J”-curve spring stiffness have the same dimensionless reference stiffness, the two-segment leg model with “J”-curve spring stiffness reveals that (1 both the largest tolerated range of running speeds and the tolerated maximum running speed are found and (2 at fast running speed from 25 to 40/92 m s−1 both the tolerated range of landing angle and the stability region are the largest. It is suggested that the two-segment leg model with “J”-curve spring stiffness is more advantageous for high-speed running compared with the SLIP model and with constant spring stiffness.

Cervical cord compression presenting with sciatica-like leg pain

OpenAIRE

Chan, Chee Keong; Lee, Ho-Yeon; Choi, Won-Chul; Cho, Ji Young; Lee, Sang-Ho

2010-01-01

Sciatica-like leg pain can be the main presenting symptom in patients with cervical cord compression. It is a false localizing presentation, which may lead to missed or delayed diagnosis, resulting in the wrong plan of management, especially in the presence of concurrent lumbar lesions. Medical history, physical findings and the results of imaging studies were reviewed in two cases of cervical cord compressions, which presented with sciatica-like leg pain. There was multi-level cervical spond...

Why do arms extract less oxygen than legs during exercise?

DEFF Research Database (Denmark)

Calbet, J A L; Holmberg, H-C; Rosdahl, H

2005-01-01

To determine whether conditions for O2 utilization and O2 off-loading from the hemoglobin are different in exercising arms and legs, six cross-country skiers participated in this study. Femoral and subclavian vein blood flow and gases were determined during skiing on a treadmill at approximately 76...... exercise (diagonal stride), the corresponding mean values were 93 and 85% (n = 3; P hemoglobin to be 50% saturated (P50: r = 0.93, P ...Hg, respectively. Because conditions for O2 off-loading from the hemoglobin are similar in leg and arm muscles, the observed differences in maximal arm and leg O2 extraction should be attributed to other factors, such as a higher heterogeneity in blood flow distribution, shorter mean transit time, smaller...

Multi-Axis Prosthetic Knee Resembles Alpine Skiing Movements of an Intact Leg

Directory of Open Access Journals (Sweden)

Ivan Demšar, Jože Duhovnik, Blaž Lešnik, Matej Supej

2015-12-01

Full Text Available The purpose of the study was to analyse the flexion angles of the ski boot, ankle and knee joints of an above-knee prosthesis and to compare them with an intact leg and a control group of skiers. One subject with an above-knee amputation of the right leg and eight healthy subjects simulated the movement of a skiing turn by performing two-leg squats in laboratory conditions. By adding additional loads in proportion to body weight (BW; +1/3 BW, +2/3 BW, +3/3 BW, various skiing regimes were simulated. Change of Flexion Angle (CoFA and Range of Motion (RoM in the ski boot, ankle and knee joints were calculated and compared. An average RoM in the skiing boot on the side of prosthesis (4.4 ± 1.1° was significantly lower compared to an intact leg (5.9 ± 1.8° and the control group (6.5 ± 2.3°. In the ankle joint, the average RoM was determined to be 13.2±2.9° in the prosthesis, 12.7 ± 2.8° in an intact leg and 14.8±3.6 in the control group. However, the RoM of the knee joint in the prosthesis (42.2 ± 4.2° was significantly larger than that of the intact leg (34.7 ± 4.4°. The average RoM of the knee joint in the control group was 47.8 ± 5.4°. The influences of additional loads on the kinematics of the lower extremities were different on the side of the prosthesis and on the intact leg. In contrast, additional loads did not produce any significant differences in the control group. Although different CoFAs in the ski boot, ankle and knee joints were used, an above-knee prosthesis with a built-in multi-axis prosthetic knee enables comparable leg kinematics in simulated alpine skiing.

A review of the relationship between leg power and selected chronic disease in older adults

DEFF Research Database (Denmark)

Strollo, S. E.; Caserotti, Paolo; Ward, R. E.

2015-01-01

characterized. Importantly, individuals with these conditions have shown improved leg power with training. METHODS: A search was performed using PubMed to identify original studies published in English from January 1998 to August 2013. Leg power studies, among older adults ≥ 50 years of age, which assessed......OBJECTIVE: This review investigates the relationship between leg muscle power and the chronic conditions of osteoarthritis, diabetes mellitus, and cardiovascular disease among older adults. Current literature assessing the impact of chronic disease on leg power has not yet been comprehensively......), diabetes mellitus (n=5), and cardiovascular disease (n=6). Studies generally supported associations of lower leg power among older adults with chronic disease, although small sample sizes, cross-sectional data, homogenous populations, varied disease definitions, and inconsistent leg power methods limited...

Mechanical evidence that flamingos can support their body on one leg with little active muscular force.

Science.gov (United States)

Chang, Young-Hui; Ting, Lena H

2017-05-01

Flamingos (Phoenicopteridae) often stand and sleep on one leg for long periods, but it is unknown how much active muscle contractile force they use for the mechanical demands of standing on one leg: body weight support and maintaining balance. First, we demonstrated that flamingo cadavers could passively support body weight on one leg without any muscle activity while adopting a stable, unchanging, joint posture resembling that seen in live flamingos. By contrast, the cadaveric flamingo could not be stably held in a two-legged pose, suggesting a greater necessity for active muscle force to stabilize two-legged versus one-legged postures. Our results suggest that flamingos engage a passively engaged gravitational stay apparatus (proximally located) for weight support during one-legged standing. Second, we discovered that live flamingos standing on one leg have markedly reduced body sway during quiescent versus alert behaviours, with the point of force application directly under the distal joint, reducing the need for muscular joint torque. Taken together, our results highlight the possibility that flamingos stand for long durations on one leg without exacting high muscular forces and, thus, with little energetic expenditure. © 2017 The Author(s).

Supporting adherence and healthy lifestyles in leg ulcer patients: systematic development of the Lively Legs program for dermatology outpatient clinics.

Science.gov (United States)

Heinen, Maud M; Bartholomew, L Kay; Wensing, Michel; van de Kerkhof, Peter; van Achterberg, Theo

2006-05-01

The objective of our project was to develop a lifestyle program for leg ulcer patients at outpatient clinics for dermatology. We used the intervention-mapping (IM) framework for systematically developing theory and evidence based health promotion programs. We started with a needs-assessment. A multidisciplinary project group of health care workers and patients was involved in all five IM steps; formulating proximal program objectives, selecting methods and strategies, producing program components, planning for adoption and implementation and planning for evaluation. Several systematic literature reviews and original studies were performed to support this process. Social Cognitive Theory was selected as the main theory behind the program 'Lively Legs' and was combined with elements of Goal-Setting Theory, the precaution adoption model and motivational interviewing. The program is conducted through health counseling by dermatology nurses and was successfully pre-tested. Also, an implementation and evaluation plan were made. Intervention mapping helped us to succeed in developing a lifestyle program with clear goals and methods, operational strategies and materials and clear procedures. Coaching leg ulcer patients towards adherence with compression therapy and healthy lifestyles should be taken on without delay. Systematic development of lifestyle programs for other patient groups should be encouraged.

Recovery, work-life balance and work experiences important to self-rated health: A questionnaire study on salutogenic work factors among Swedish primary health care employees.

Science.gov (United States)

Ejlertsson, Lina; Heijbel, Bodil; Ejlertsson, Göran; Andersson, Ingemar

2018-01-01

There is a lack of information on positive work factors among health care workers. To explore salutogenic work-related factors among primary health care employees. Questionnaire to all employees (n = 599) from different professions in public and private primary health care centers in one health care district in Sweden. The questionnaire, which had a salutogenic perspective, included information on self-rated health from the previously validated SHIS (Salutogenic Health Indicator Scale), psychosocial work environment and experiences, recovery, leadership, social climate, reflection and work-life balance. The response rate was 84%. A multivariable linear regression model, with SHIS as the dependent variable, showed three significant predictors. Recovery had the highest relationship to SHIS (β= 0.34), followed by experience of work-life balance (β= 0.25) and work experiences (β= 0.20). Increased experience of recovery during working hours related to higher self-rated health independent of recovery outside work. Individual experiences of work, work-life balance and, most importantly, recovery seem to be essential areas for health promotion. Recovery outside the workplace has been studied previously, but since recovery during work was shown to be of great importance in relation to higher self-rated health, more research is needed to explore different recovery strategies in the workplace.

Pathogenicity of two recent Western Mediterranean West Nile virus isolates in a wild bird species indigenous to Southern Europe: the red-legged partridge

Directory of Open Access Journals (Sweden)

Sotelo Elena

2011-01-01

Full Text Available Abstract West Nile virus (WNV is an emerging zoonotic pathogen whose geographic spread and incidence in humans, horses and birds has increased significantly in recent years. WNV has long been considered a mild pathogen causing self-limiting outbreaks. This notion has changed as WNV is causing large epidemics with a high impact on human and animal health. This has been particularly noteworthy since its introduction into North America in 1999. There, native bird species have been shown to be highly susceptible to WNV infection and disease with high mortalities. For this reason, the effect of WNV infection in North American bird species has been thoroughly studied by means of experimental inoculations in controlled trials. To a lesser extent, European wild birds have been shown to be affected clinically by WNV infection. Yet experimental studies on European wild bird species are lacking. The red-legged partridge (Alectoris rufa is a gallinaceous bird indigenous to the Iberian Peninsula, widely distributed in South Western Europe. It plays a key role in the Mediterranean ecosystem and constitutes an economically important game species. As such it is raised intensively in outdoor facilities. In this work, red-legged partridges were experimentally infected with two recent WNV isolates from the Western Mediterranean area: Morocco/2003 and Spain/2007. All inoculated birds became viremic and showed clinical disease, with mortality rates of 70% and 30%, respectively. These results show that Western Mediterranean WNV variants can be pathogenic for some European bird species, such as the red-legged partridge.

Simulation and development of a multi-leg homogeniser concentrating assembly for concentrated photovoltaic (CPV) system with electrical rating analysis

KAUST Repository

Burhan, Muhammad

2016-03-09

Concentrated photovoltaic (CPV) system utilizing multi-junction solar cells, is the main focus for current research, offering highest efficiency among all photovoltaic systems. The main aspect of CPV system is the design and performance of concentrating assembly, as it determines the performance of whole CPV system. However, the conventional design of CPV concentrating assembly dedicates one concentrator for each solar cell, in which single concentrator is capable to concentrate solar radiation onto single solar cell. This paper proposes a novel concentrating assembly for CPV system, which is designed to concentrate solar radiation onto four multi-junction solar cells with a single set of concentrators. The proposed design not only can reduce the number of concentrators and assembly efforts for CPV systems, but also achieved an acceptance angle of 1°. In this paper, the proposed multi-leg homogeniser CPV concentrating assembly is designed, developed, experimentally tested and verified through ray tracing simulation. The paper also discuss the development of mini, precise and accurate but cost effective two axis solar tracker for CPV system, which can be installed at any location even at rooftop of residential buildings, unlike conventional large scale CPV systems. Moreover, through the electrical rating analysis of the developed CPV system, its performance can be accurately estimated in any region. © 2016 Elsevier Ltd. All rights reserved.

Simulation and development of a multi-leg homogeniser concentrating assembly for concentrated photovoltaic (CPV) system with electrical rating analysis

KAUST Repository

Burhan, Muhammad; Chua, Kian Jon Ernest; Ng, Kim Choon

2016-01-01

Concentrated photovoltaic (CPV) system utilizing multi-junction solar cells, is the main focus for current research, offering highest efficiency among all photovoltaic systems. The main aspect of CPV system is the design and performance of concentrating assembly, as it determines the performance of whole CPV system. However, the conventional design of CPV concentrating assembly dedicates one concentrator for each solar cell, in which single concentrator is capable to concentrate solar radiation onto single solar cell. This paper proposes a novel concentrating assembly for CPV system, which is designed to concentrate solar radiation onto four multi-junction solar cells with a single set of concentrators. The proposed design not only can reduce the number of concentrators and assembly efforts for CPV systems, but also achieved an acceptance angle of 1°. In this paper, the proposed multi-leg homogeniser CPV concentrating assembly is designed, developed, experimentally tested and verified through ray tracing simulation. The paper also discuss the development of mini, precise and accurate but cost effective two axis solar tracker for CPV system, which can be installed at any location even at rooftop of residential buildings, unlike conventional large scale CPV systems. Moreover, through the electrical rating analysis of the developed CPV system, its performance can be accurately estimated in any region. © 2016 Elsevier Ltd. All rights reserved.

Measurement of L-[1-14C]leucine kinetics in splanchnic and leg tissues in humans. Effect of amino acid infusion

International Nuclear Information System (INIS)

Gelfand, R.A.; Glickman, M.G.; Castellino, P.; Louard, R.J.; DeFronzo, R.A.

1988-01-01

Although whole-body leucine flux is widely measured to study body protein turnover in humans, the contribution of specific tissues to the total-body measurement remains unknown. By combining the organ-balance technique with the systemic infusion of L-[1-14C]leucine, we quantitated leucine production and disposal by splanchnic and leg tissues and by the whole body, simultaneously, in six normal men before and during amino acid infusion. At steady state, disposal of arterial leucine by splanchnic and leg tissues was calculated from the percent extraction (E) of L-[1-14C]leucine counts: uptake = E x [Leu]a x flow. Tissue release of cold leucine (from protein turnover) into vein was calculated as the difference between leucine uptake and the net tissue leucine balance. In the postabsorptive state, despite substantial (P less than .01) extraction of L-[1-14C]leucine by splanchnic (23 +/- 1%) and leg (18 +/- 2%) tissues, net leucine balance across both tissue beds was small, indicating active simultaneous disposal and production of leucine at nearly equivalent rates. Splanchnic tissues accounted for approximately 50% of the measured total-body leucine flux. During amino acid infusion, the net leucine balance across splanchnic and leg tissues became positive, reflecting not only an increase in leucine uptake but also a marked suppression (by approximately 50%, P less than .02) of cold leucine release. This reduction in splanchnic and leg leucine release was indicated by a sharp decline in whole-body endogenous leucine flux

The relationship with restless legs syndrome, fibromyalgia, and depressive symptoms in migraine patients.

Science.gov (United States)

Akdag Uzun, Zehra; Kurt, Semiha; Karaer Unaldi, Hatice

2018-05-18

In this study, we aimed to investigate restless legs syndrome, depression, frequency of fibromyalgia and possible causes of its frequencies, and the relationships among these synergies and migraine's prodrome, aura, pain, and postdrome symptoms in patients with migraine. The study group included 200 patients previously or recently diagnosed with definite migraine and according to International Headache Society criteria and 200 healthy volunteers. All subjects underwent a medical interview to confirm restless legs syndrome and fibromyalgia, and they were asked to complete Beck Depression and Anxiety Inventory and "severity of restless legs syndrome inventory." The frequencies of depressive symptoms and fibromyalgia in the patients with migraine were higher than those of the control group. The mean age of the migraine patients with restless legs syndrome was also higher, and this group had migraine headache for a longer time. There was a statistically significant difference with regard to only generalized anxiety and traveler's distress, which were features of the migraine, between migraine patients with and without restless legs syndrome. Restless legs syndrome was more common in migraine patients with and without aura and in those with nonspecific white matter lesions in the cranial MRI. In our study, the greater frequency of restless legs syndrome, depressive symptoms, and fibromyalgia in the patients with migraine supports the role of dopamine, which is common to all three disorders. Interviews focused on these problems among migraine patients may help to decide on the best available treatment modality.

Biomechanical pole and leg characteristics during uphill diagonal roller skiing.

Science.gov (United States)

Lindinger, Stefan Josef; Göpfert, Caroline; Stöggl, Thomas; Müller, Erich; Holmberg, Hans-Christer

2009-11-01

Diagonal skiing as a major classical technique has hardly been investigated over the last two decades, although technique and racing velocities have developed substantially. The aims of the present study were to 1) analyse pole and leg kinetics and kinematics during submaximal uphill diagonal roller skiing and 2) identify biomechanical factors related to performance. Twelve elite skiers performed a time to exhaustion (performance) test on a treadmill. Joint kinematics and pole/plantar forces were recorded separately during diagonal roller skiing (9 degrees; 11 km/h). Performance was correlated to cycle length (r = 0.77; P Push-off demonstrated performance correlations for impulse of leg force (r = 0.84), relative duration (r= -0.76) and knee flexion (r = 0.73) and extension ROM (r = 0.74). Relative time to peak pole force was associated with performance (r = 0.73). In summary, diagonal roller skiing performance was linked to 1) longer cycle length, 2) greater impulse of force during a shorter push-off with larger flexion/extension ROMs in leg joints, 3) longer leg swing, and 4) later peak pole force, demonstrating the major key characteristics to be emphasised in training.

Study on improvement of energy efficiency of walking robots by spring -installed leg design

International Nuclear Information System (INIS)

Shin, Eung Soo; Song, Heuy Gap

1993-01-01

Although a walking robot is potentially useful in nuclear industry, its application has not been successful so far due to poor energy efficiency. In this paper, dynamic spring balancing of a swinging leg is proposed for improving energy efficiency. Since the fluctuation of internal energy is unavoidable due to leg oscillation, springs can be used for storing energy that is otherwise dissipated at the end of the return phase of the leg. Based of approximation to harmonic oscillation, an optimum trajectory and spring parameters are simultaneously synthesized for the leg in the return phase. (Author)

A new biarticular actuator design facilitates control of leg function in BioBiped3.

Science.gov (United States)

Sharbafi, Maziar Ahmad; Rode, Christian; Kurowski, Stefan; Scholz, Dorian; Möckel, Rico; Radkhah, Katayon; Zhao, Guoping; Rashty, Aida Mohammadinejad; Stryk, Oskar von; Seyfarth, Andre

2016-07-01

Bioinspired legged locomotion comprises different aspects, such as (i) benefiting from reduced complexity control approaches as observed in humans/animals, (ii) combining embodiment with the controllers and (iii) reflecting neural control mechanisms. One of the most important lessons learned from nature is the significant role of compliance in simplifying control, enhancing energy efficiency and robustness against perturbations for legged locomotion. In this research, we investigate how body morphology in combination with actuator design may facilitate motor control of leg function. Inspired by the human leg muscular system, we show that biarticular muscles have a key role in balancing the upper body, joint coordination and swing leg control. Appropriate adjustment of biarticular spring rest length and stiffness can simplify the control and also reduce energy consumption. In order to test these findings, the BioBiped3 robot was developed as a new version of BioBiped series of biologically inspired, compliant musculoskeletal robots. In this robot, three-segmented legs actuated by mono- and biarticular series elastic actuators mimic the nine major human leg muscle groups. With the new biarticular actuators in BioBiped3, novel simplified control concepts for postural balance and for joint coordination in rebounding movements (drop jumps) were demonstrated and approved.

The Influence of Bi Rate to the Distribution of Working Capital Loans

OpenAIRE

Dian Kurnianingrum

2015-01-01

This research “The influence of BI rate to the distribution of working capital loans" is conducted at Indonesian commercial bank during the month of January 2005 until May 2009. The purpose of this research is to determine the effect of BI rate toward the distribution of working capital loans. To test the research hypotheses, the data were analyzed by using Pearson correlate and simple linear regression. Based on research, BI rate significantly influence the distribution of working capital lo...

An MRI volumetric study for leg muscles in congenital clubfoot.

Science.gov (United States)

Ippolito, Ernesto; Dragoni, Massimiliano; Antonicoli, Marco; Farsetti, Pasquale; Simonetti, Giovanni; Masala, Salvatore

2012-10-01

To investigate both volume and length of the three muscle compartments of the normal and the affected leg in unilateral congenital clubfoot. Volumetric magnetic resonance imaging (VMRI) of the anterior, lateral and postero-medial muscular compartments of both the normal and the clubfoot leg was obtained in three groups of seven patients each, whose mean age was, respectively, 4.8 months, 11.1 months and 4.7 years. At diagnosis, all the unilateral congenital clubfeet had a Pirani score ranging from 4.5 to 5.5 points, and all of them had been treated according to a strict Ponseti protocol. All the feet had percutaneous lengthening of the Achilles tendon. A mean difference in both volume and length was found between the three muscular compartments of the leg, with the muscles of the clubfoot side being thinner and shorter than those of the normal side. The distal tendon of the tibialis anterior, peroneus longus and triceps surae (Achilles tendon) were longer than normal on the clubfoot side. Our study shows that the three muscle compartments of the clubfoot leg are thinner and shorter than normal in the patients of the three groups. The difference in the musculature volume of the postero-medial compartment between the normal and the affected side increased nine-fold from age group 2 to 3, while the difference in length increased by 20 %, thus, showing that the muscles of the postero-medial compartment tend to grow in both thickness and length much less than the muscles of the other leg compartments.

Leg tissue composition and physico-chemical parameters of sheep meat fed annatto coproduct

Directory of Open Access Journals (Sweden)

Dorgival Morais de Lima Júnior

2017-10-01

Full Text Available Our objective was to evaluate leg tissue composition and physico-chemical quality parameters of sheep meat fed with increasing levels of annatto coproduct. 32 male uncastrated animals without a defined breed were randomized in four treatments (0, 100, 200 and 300 g kg-1 of annatto coproduct in the DM diet. After 78 days of confinement, the animals were slaughtered and body components were recorded. Reconstituted leg weight, total muscle weight, biceps weight and semitendinosus weight showed a negative linear behavior (P 0.05 were found for leg tissue composition (%, muscle:bone ratio, relative fat or leg muscle. Meat physico-chemical parameters (color, shear force, water retention capacity and cooking losses were not affected by the inclusion of the annatto coproduct in the diet. The annatto coproduct can be included in up to 300 g kg-1 of dietary dry matter without negative effects to the leg tissue composition (% and physical parameters of confined sheep meat.

Analysis of hot leg natural circulation under station blackout severe accident

International Nuclear Information System (INIS)

Deng Jian; Cao Xuewu

2007-01-01

Under severe accidents, natural circulation flows are important to influence the accident progression and result in a pressurized water reactor (PWR). In a station blackout accident with no recovery of steam generator (SG) auxiliary feedwater (TMLB' severe accident scenario), the hot leg countercurrent natural circulation flow is analyzed by using a severe-accident code, to better understand its potential impacts on the creep-rupture timing among the surge line, the hot leg; and SG tubes. The results show that the natural circulation may delay the failure time of the hot leg. The recirculation ratio and the hot mixing factor are also calculated and discussed. (authors)

Biologically Inspired Modular Neural Control for a Leg-Wheel Hybrid Robot

DEFF Research Database (Denmark)

Manoonpong, Poramate; Wörgötter, Florentin; Laksanacharoen, Pudit

2014-01-01

In this article we present modular neural control for a leg-wheel hybrid robot consisting of three legs with omnidirectional wheels. This neural control has four main modules having their functional origin in biological neural systems. A minimal recurrent control (MRC) module is for sensory signal...... processing and state memorization. Its outputs drive two front wheels while the rear wheel is controlled through a velocity regulating network (VRN) module. In parallel, a neural oscillator network module serves as a central pattern generator (CPG) controls leg movements for sidestepping. Stepping directions...... or they can serve as useful modules for other module-based neural control applications....

Crossed Leg Sign Is Associated With Severity of Unilateral Spatial Neglect After Stroke

Directory of Open Access Journals (Sweden)

Gustavo José Luvizutto

2018-04-01

Full Text Available BackgroundThe crossed leg sign in patients with right hemisphere stroke is thought to be associated with perceptual disorders, such as unilateral spatial neglect (USN. The aim of this study was to compare the crossed leg sign with the severity of USN during the acute phase of stroke.Experimental proceduresThis was an observational and prospective clinical study of individuals with a diagnosis of right parietal stroke, as confirmed by neuroimaging. The occurrence of the crossed leg sign, the time at which this occurred after the stroke, and a clinical diagnosis of USN were measured and recorded. The patients’ age, sex, and lesion severity, as determined by the National Institutes of Health Stroke Scale and Glasgow coma scale, were included in the analyses as confounding variables. The outcome of interest was the degree of USN, as measured by the cancellation and bisection tests. Binary logistic regression was used to analyze the effect of crossed leg syndrome on the severity of USN. In the adjusted multiple regression model, a p-value of <0.05 was considered statistically significant.ResultsOverall, 60 patients were included in this study. There were no associations between patient demographics and the presence of the crossed leg sign. There was, however, an association between the crossed leg sign and the absolute value of the deviation in the line bisection test (B = −0.234; p = 0.039. The crossed leg sign was not associated with other measures of USN.ConclusionBased on the results of our study, we can conclude that a crossed leg sign in the acute phase of stroke is associated with USN severity, specifically the misinterpretation of the midline.

Magnetic field effects of tow-leg Heisenberg antiferromagnetic ladders: Thermodynamic properties

International Nuclear Information System (INIS)

Wang Xiaoqun; Yu Lu

2000-05-01

Using the recently developed transfer-matrix renormalization group method, we have studied the thermodynamic properties of two-leg antiferromagnetic ladders in the magnetic field. Based on different behavior of magnetization, we found disordered spin liquid, Luttinger liquid, spin-polarized phases and a classical regime depending on magnetic field and temperature. Our calculations in Luttinger liquid regime suggest that both the divergence of the NMR relaxation rate and the anomalous specific heat behavior observed on Cu 2 (C 5 H 12 N 2 ) 2 Cl 4 are due to quasi-one-dimensional effect rather than three-dimensional ordering. (author)

Leg Preference and Interlateral Asymmetry of Balance Stability in Soccer Players

Science.gov (United States)

Teixeira, Luis Augusto; de Oliveira, Dalton Lustosa; Romano, Rosangela Guimaraes; Correa, Sonia Cavalcanti

2011-01-01

To examine the effect of long lasting practice on pedal behavior in sport, we compared experienced adult soccer players and nonsoccer players on leg preference in motor tasks requiring general mobilization, soccer related mobilization, and body balance stabilization. We also evaluated performance asymmetry between the right and left legs in static…

Significance of rate of work hardening in tempered martensite embrittlement

International Nuclear Information System (INIS)

Pietikainen, J.

1995-01-01

The main explanations for tempered martensite embrittlement are based on the effects of impurities and cementite precipitation on the prior austenite grain boundaries. There are some studies where the rate of work hardening is proposed as a potential reason for the brittleness. One steel was studied by means of a specially developed precision torsional testing device. The test steel had a high Si and Ni content so ε carbide and Fe 3 C appear in quite different tempering temperature ranges. The M S temperature is low enough so that self tempering does not occur. With the testing device it was possible to obtain the true stress - true strain curves to very high deformations. The minimum toughness was always associated with the minimum of rate of work hardening. The change of deformed steel volume before the loss of mechanical stability is proposed as at least one reason for tempered martensite embrittlement. The reasons for the minimum of the rate of work hardening are considered. (orig.)

Does structural leg-length discrepancy affect postural control? Preliminary study.

Science.gov (United States)

Eliks, Małgorzata; Ostiak-Tomaszewska, Wioleta; Lisiński, Przemysław; Koczewski, Paweł

2017-08-09

Leg-length inequality results in an altered position of the spine and pelvis. Previous studies on the influence of leg asymmetry on postural control have been inconclusive. The purpose of this paper was to investigate the effect of structural leg-length discrepancy (LLD) on the control of posture. We studied 38 individuals (19 patients with structural LLD, 19 healthy subjects). The examination included measurement of the length of the lower limbs and weight distribution as well as a static posturography. All statistical analyses were performed with Statistica software version 10.0. Non-parametrical Kruskal-Wallis with Dunn's post test and Spearman test were used. Differences between the groups and correlation between mean COP sway velocity and the value of LLD as well as the value of LLD and weight distribution were assumed as statistically significant at p  0.05). Meaningful differences in mean COP velocity in mediolateral direction between tandem stance with eyes open and closed were detected in both groups (in controls p = 0.000134, in patients both with the shorter leg in a front and rear position, p = 0.029, p = 0.026 respectively). There was a positive moderate correlation between the value of LLD and the value of mean COP velocity in normal standing in mediolateral direction with eyes open (r = 0.47) and closed (r = 0.54) and in anterioposterior plane with eyes closed (r = 0.05). The fact that there were no significant differences in posturography between the groups might indicate compensations to the altered posture and neuromuscular adaptations in patients with structural leg-length inequality. LLD causes an increased asymmetry of weight distribution. This study confirmed a fundamental role of the sight in postural control, especially in unstable conditions. The analysis of mean COP sway velocity may suggest a proportional deterioration of postural control with the increase of the value of leg-length asymmetry. Trial registry: Clinical

Angiographic imaging of the branching of the popliteal artery into the arteries of the lower leg

International Nuclear Information System (INIS)

Prayer, L.; Karnel, F.; Schurawitzki, H.

1990-01-01

For the anatomic analysis of the branching of the popliteal artery into the lower leg arteries, 414 intra-arterial DSA images of the lower extremity (obtained in 223 patients) were available. In 90.1% of the material examined, a 'normal' branching was found. If one leg of a patient showed 'normal' branching, there was a probability of 6.9% to find a different branching of the artery in the other leg. In 9.9% of the examined legs deviations from standard branching were observed. If there was a deviation from standard observed in one leg, the probability of finding a variant of branching in the other leg as well was 4.4%. (orig./MG) [de

Impact of UK NICE clinical guidelines 168 on referrals to a specialist academic leg ulcer service.

Science.gov (United States)

Davies, Huw Ob; Popplewell, Matthew; Bate, Gareth; Kelly, Lisa; Darvall, Katy; Bradbury, Andrew W

2018-03-01

Background Leg ulcers are a common cause of morbidity and disability and result in significant health and social care expenditure. The UK National Institute for Health and Care Excellence (NICE) Clinical Guideline (CG)168, published in July 2013, sought to improve care of patients with leg ulcers, recommending that patients with a break in the skin below the knee that had not healed within two weeks be referred to a specialist vascular service for diagnosis and management. Aim Determine the impact of CG168 on referrals to a leg ulcer service. Methods Patients referred with leg ulceration during an 18-month period prior to CG168 (January 2012-June 2013) and an 18-month period commencing six months after (January 2014-June 2015) publication of CG168 were compared. Results There was a two-fold increase in referrals (181 patients, 220 legs vs. 385 patients, 453 legs) but no change in mean age, gender or median-duration of ulcer at referral (16.6 vs. 16.2 weeks). Mean-time from referral to specialist appointment increased (4.8 vs. 6 weeks, p = 0.0001), as did legs with superficial venous insufficiency (SVI) (36% vs. 44%, p = 0.05). There was a trend towards more SVI endovenous interventions (32% vs. 39%, p = 0.271) with an increase in endothermal (2 vs. 32 legs, p = 0.001) but no change in sclerotherapy (24 vs. 51 legs) treatments. In both groups, 62% legs had compression. There was a reduction in legs treated conservatively with simple dressings (26% vs. 15%, p = 0.0006). Conclusions Since CG168, there has been a considerable increase in leg ulcer referrals. However, patients are still not referred until ulceration has been present for many months. Although many ulcers are multi-factorial and the mainstay of treatment remains compression, there has been an increase in SVI endovenous intervention. Further efforts are required to persuade community practitioners to refer patients earlier, to educate patients and encourage further investment in

A Biological Micro Actuator: Graded and Closed-Loop Control of Insect Leg Motion by Electrical Stimulation of Muscles

Science.gov (United States)

Cao, Feng; Zhang, Chao; Vo Doan, Tat Thang; Li, Yao; Sangi, Daniyal Haider; Koh, Jie Sheng; Huynh, Ngoc Anh; Aziz, Mohamed Fareez Bin; Choo, Hao Yu; Ikeda, Kazuo; Abbeel, Pieter; Maharbiz, Michel M.; Sato, Hirotaka

2014-01-01

In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle) via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage) required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle) and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect–machine hybrid legged robot). PMID:25140875

A biological micro actuator: graded and closed-loop control of insect leg motion by electrical stimulation of muscles.

Directory of Open Access Journals (Sweden)

Feng Cao

Full Text Available In this study, a biological microactuator was demonstrated by closed-loop motion control of the front leg of an insect (Mecynorrhina torquata, beetle via electrical stimulation of the leg muscles. The three antagonistic pairs of muscle groups in the front leg enabled the actuator to have three degrees of freedom: protraction/retraction, levation/depression, and extension/flexion. We observed that the threshold amplitude (voltage required to elicit leg motions was approximately 1.0 V; thus, we fixed the stimulation amplitude at 1.5 V to ensure a muscle response. The leg motions were finely graded by alternation of the stimulation frequencies: higher stimulation frequencies elicited larger leg angular displacement. A closed-loop control system was then developed, where the stimulation frequency was the manipulated variable for leg-muscle stimulation (output from the final control element to the leg muscle and the angular displacement of the leg motion was the system response. This closed-loop control system, with an optimized proportional gain and update time, regulated the leg to set at predetermined angular positions. The average electrical stimulation power consumption per muscle group was 148 µW. These findings related to and demonstrations of the leg motion control offer promise for the future development of a reliable, low-power, biological legged machine (i.e., an insect-machine hybrid legged robot.

Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

Science.gov (United States)

Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

2012-04-01

Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

TRUNK LEAN DURING A SINGLE-LEG SQUAT IS ASSOCIATED WITH TRUNK LEAN DURING PITCHING.

Science.gov (United States)

Plummer, Hillary A; Oliver, Gretchen D; Powers, Christopher M; Michener, Lori A

2018-02-01

Impaired trunk motion during pitching may be a risk factor for upper extremity injuries. Specifically, increased forces about the shoulder and elbow have been observed in pitchers with excessive contralateral trunk lean during pitching. Because of the difficulty in identifying abnormal trunk motions during a high-speed task such as pitching, a clinical screening test is needed to identify pitchers who have impaired trunk motion during pitching. The purpose of this study was to determine the relationship between the degree of lateral trunk lean during the single-leg squat and amount of trunk lean during pitching and if trunk lean during pitching can be predicted from lean during the single-leg squat. Controlled Laboratory Study; Cross-sectional. Seventy-three young baseball pitchers (11.4 ± 1.7 years; 156.3 ± 11.9 cm; 50.5 ± 8.8 kg) participated. An electromagnetic tracking system was used to obtain trunk kinematic data during a single-leg squat task (lead leg) and at maximum shoulder external rotation of a fastball pitch. Pearson correlation coefficients for trunk lean during the single-leg squat and pitching were calculated. A linear regression analysis was performed to determine if trunk lean during pitching can be predicted from lean during the single-leg squat. There was a positive correlation between trunk lean during the single-leg squat and trunk lean during pitching (r = 0.53; plean during the single-leg squat predicted the amount of lateral trunk lean during pitching (R 2 = 0.28; p lean during an SLS and pitching. Trunk lean during the single-leg squat explained 28% of the variance in trunk lean during pitching. Diagnosis, level 3.

Postprandial triacylglycerol uptake in the legs is increased during exercise and post-exercise recovery

DEFF Research Database (Denmark)

Enevoldsen, L H; Simonsen, L; Bülow, J

2005-01-01

plasma triacylglycerol (TAG) uptake and clearance in the exercising legs immediately and for at least 4 h post-exercise, while food intake per se did not change leg plasma TAG uptake or clearance for up to 6 h. It is hypothesized that the effect of exercise on leg plasma TAG metabolism is a result...

Metabolic rate and gross efficiency at high work rates in world class and national level sprint skiers.

Science.gov (United States)

Sandbakk, Øyvind; Holmberg, Hans-Christer; Leirdal, Stig; Ettema, Gertjan

2010-06-01

The present study investigated metabolic rate (MR) and gross efficiency (GE) at moderate and high work rates, and the relationships to gross kinematics and physical characteristics in elite cross-country skiers. Eight world class (WC) and eight national level (NL) male sprint cross-country skiers performed three 5-min stages using the skating G3 technique, whilst roller skiing on a treadmill. GE was calculated by dividing work rate by MR. Work rate was calculated as the sum of power against gravity and frictional rolling forces. MR was calculated using gas exchange and blood lactate values. Gross kinematics, i.e. cycle length (CL) and cycle rate (CR) were measured by video analysis. Furthermore, the skiers were tested for time to exhaustion (TTE), peak oxygen uptake (VO(2peak)), and maximal speed (V(max)) on the treadmill, and maximal strength in the laboratory. Individual performance level in sprint skating was determined by FIS points. WC skiers did not differ in aerobic MR, but showed lower anaerobic MR and higher GE than NL skiers at a given speed (all P higher V(max) and TTE (all P better technique and to technique-specific power.

Immobilization increases interleukin-6, but not tumour necrosis factor-a, release from the leg during exercise in humans

DEFF Research Database (Denmark)

Reihmane, Dace; Hansen, Andreas Vigelsø; Jensen, Martin Gram

2013-01-01

have now studied the temporal relationship of leg IL-6 and TNF-a release before and during isolated two-legged exercise after 14 days of one-leg immobilization (IM) while the other leg served as the control (CON) leg. Fifteen healthy male subjects (mean ± SEM age, 23 ± 1 years; body mass index, 23.......6 ± 0.7 kg m; and maximal oxygen uptake, 46.8 ± 1.4 ml kg min) performed 45 min of two-legged dynamic knee-extensor exercise at 19.6 ± 0.8 W. Arterial and femoral venous blood samples from the CON and the IM leg were collected every 15 min during exercise, and leg blood flow was measured with Doppler...

Transcutaneous laser treatment of leg veins

NARCIS (Netherlands)

Meesters, Arne A.; Pitassi, Luiza H. U.; Campos, Valeria; Wolkerstorfer, Albert; Dierickx, Christine C.

2014-01-01

Leg telangiectasias and reticular veins are a common complaint affecting more than 80% of the population to some extent. To date, the gold standard remains sclerotherapy for most patients. However, there may be some specific situations, where sclerotherapy is contraindicated such as needle phobia,

Replacing of live food with artificial diet on growth and survival rates of white leg shrimp (Litopenaeus vannamei) larvae

OpenAIRE

Ghorbani Vagheie, R.; Matinfar, A.; Aeinjamshid, Kh.; Hafezieh, M.; Ghorbani, R.

2011-01-01

Replacing live food with artificial diets in aquatic larviculture, especially in shrimp larvae not only is caused convenience feeding, but also in economical view is very important. With this object, in this survey, a density of 100.L -1 white leg shrimp larvae in 9 nutritional treatments each with three replicates were cultured in 20L tanks each one was held with 10L of 30% salty water using one air stone. The larvae were fed 4 times.day-1 with different diets, including live foods (Cheatoce...

Influence of the cognitive workload on bicycle safety at four-legged intersections

DEFF Research Database (Denmark)

Kveladze, Irma; Agerholm, Niels

2018-01-01

is the influence of workload capacity on bicyclists spatial behaviour in a natural environment of four-legged intersections. Method: Due to the traffic safety of test participants, the study is divided in two phases. In the first phase, the actual physical environment of the four-legged intersection and bicyclists......-legged intersection. The eye tracking glasses will be used to make video and audio recording of visible field of where or how long bicyclists are allocating their visual attention while riding a bicycle and facing obstacles when crossing the four-legged intersection. On the second phase, a bicycle riding simulator...... riding task. This will allow to understand the allocation of bicyclists attention between primary and secondary tasks, to reveal the limit of the information processing capacity during biking. Results expected: Two experimental results will be incorporated to gain in-depth knowledge on bicycle accidents...

RELAP5 simulation of a large break Loss of Coolant Accident (LOCA) in the hot leg of the primary system in Angra 2 nuclear power plant

International Nuclear Information System (INIS)

Andrade, Delvonei Alves de; Sabundjian, Gaiane

2004-01-01

The objective of this work is to present the simulation of a large break loss of coolant accident - LBLOCA in the hot leg of the primary loop in Angra 2, with RELAP5/MOD3.2.2g code. This accident is described in the Final Safety Report Analysis of Angra 2 - FSAR and consists basically of the hot leg total break, in loop 20 of the plant. The area considered for the rupture is 4480 cm 2 , which corresponds to 100% of the pipe flow area. Besides, this work also has the objective of verifying the efficiency of the emergency core coolant system - ECCS in case of accidents and transients. The thermal-hydraulic processes inherent to the accident phenomenology, such as hot leg vaporization and consequently core vaporization causing an inappropriate flow distribution in the reactor core, can lead to a reduction in the liquid level, until the ECCS is capable to reflood it

Automated Management of Exercise Intervention at the Point of Care: Application of a Web-Based Leg Training System.

Science.gov (United States)

Dedov, Vadim N; Dedova, Irina V

2015-11-23

Recent advances in information and communication technology have prompted development of Web-based health tools to promote physical activity, the key component of cardiac rehabilitation and chronic disease management. Mobile apps can facilitate behavioral changes and help in exercise monitoring, although actual training usually takes place away from the point of care in specialized gyms or outdoors. Daily participation in conventional physical activities is expensive, time consuming, and mostly relies on self-management abilities of patients who are typically aged, overweight, and unfit. Facilitation of sustained exercise training at the point of care might improve patient engagement in cardiac rehabilitation. In this study we aimed to test the feasibility of execution and automatic monitoring of several exercise regimens on-site using a Web-enabled leg training system. The MedExercise leg rehabilitation machine was equipped with wireless temperature sensors in order to monitor its usage by the rise of temperature in the resistance unit (Δt°). Personal electronic devices such as laptop computers were fitted with wireless gateways and relevant software was installed to monitor the usage of training machines. Cloud-based software allowed monitoring of participant training over the Internet. Seven healthy participants applied the system at various locations with training protocols typically used in cardiac rehabilitation. The heart rates were measured by fingertip pulse oximeters. Exercising in home chairs, in bed, and under an office desk was made feasible and resulted in an intensity-dependent increase of participants' heart rates and Δt° in training machine temperatures. Participants self-controlled their activities on smart devices, while a supervisor monitored them over the Internet. Individual Δt° reached during 30 minutes of moderate-intensity continuous training averaged 7.8°C (SD 1.6). These Δt° were used as personalized daily doses of exercise with

Role of lymphoscintigraphy in diagnosis and management of patients with leg swelling of unclear etiology

International Nuclear Information System (INIS)

Kalawat, Tek Chand; Chittoria, Ravi Kumar; Reddy, Praveen Kumar; Suneetha, Batchu; Narayan, Ravishwar; Ravi, Parthsarthi

2012-01-01

To study the utility of lymphoscintigraphy in detection of lymphatic obstruction in patients with leg swelling of unclear etiology, selection of site for nodo venous shunt procedure, and follow-up lymphoscintigraphic documentation of improved lymph flow in surgically treated limb. Twenty four consecutive patients with leg swelling, 10 male, 14 female with mean age 47 years, range from 13 years to 74 years underwent lymphoscintigraphy. All patients were referred from Department of Plastic Surgery, after initial work-up, and routine investigations to rule out the other causes of leg swelling. Both clinical and scintigraphic staging performed for all patients. All clinically and scintigraphically positive patients treated with decongestive lymphatic therapy (DLT). In addition to the DLT, those patients positive for unilateral or bilateral lymphedema, consented for surgical intervention, nodo venous shunt (NVS) in their only affected or one of the two affected lower limbs. Follow-up lymphoscintigraphy performed in operated cases after 3 months to 6 months of surgery, lymphoscintigraphy images of each patient in pre and post-surgery compared. In 20/24 cases (83%) of clinically positive leg swelling were found to be positive for lymphedema on lymphoscintigraphy and remaining, 4/24 were scintigraphically normal. Based on the clinical and lymphoscintigraphy staging, 03/20 cases (15%) had Grade I lymphedema, 01/20 (5%) Grade II lymphedema, 06/20 (30%) Grade III and remaining 10/20 (50%) had Grade IV lymphedema. 11/20 cases of Lymphedema (55%) were managed conservatively by only DLT and in remaining 09/20 cases (45%), who were case of Grade IV, lymphedema (five patients with unilateral and four patients with bilateral disease) initially treated with DLT, and on completion of DLT, undergone for NVS procedure, in their unilaterally affected lower limb or one of the two diseased lower limbs. All nine patients showed remarkable clinical improvement in leg swelling and their

Muscle Activity in Single- vs. Double-Leg Squats.

Science.gov (United States)

DeFOREST, Bradley A; Cantrell, Gregory S; Schilling, Brian K

Muscular activity, vertical displacement and ground reaction forces of back squats (BS), rear-leg elevated split squats (RLESS) and split squats (SS) were examined. Nine resistance-trained men reported for two sessions. The first session consisted of the consent process, practice, and BS 1-repetition maximum testing. In the second session, participants performed the three exercises while EMG, displacment and ground reaction force data (one leg on plate) were collected. EMG data were collected from the gluteus maximus (GMX), biceps femoris (BF), semitendinosus (ST), rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), and medial gastrocnemius (MGas) of the left leg (non-dominant, front leg for unilateral squats). Load for BS was 85% one repetition maximum, and RLESS and SS were performed at 50% of BS load. Repeated measures ANOVA was used to compare all variables for the three exercises, with Bonferroni adjustments for post hoc multiple comparisons, in addition to calculation of standardized mean differences (ES). Muscle activity was similar between exercises except for biceps femoris, which was significantly higher during RLESS than SS during both concentric and eccentric phases (ES = 2.11; p=0.012 and ES= 2.19; p=0.008), and significantly higher during BS than the SS during the concentric phase (ES = 1.78; p=0.029). Vertical displacement was similar between all exercises. Peak vertical force was similar between BS and RLESS and significantly greater during RLESS than SS (ES = 3.03; p=0.001). These findings may be helpful in designing resistance training programs by using RLESS if greater biceps femoris activity is desired.

Embodiment of Legged Robots Emerged in Evolutionary Design: Pseudo Passive Dynamic Walkers

OpenAIRE

Matsushita, Kojiro; Yokoi, Hiroshi

2008-01-01

An objective of this paper is to illustrate a physical representation of the embodiment on legged locomotion. Embodiment is here defined as physical features that reduce control complexity and energy consumption of legged robots. In this method, the embodiment of

[Dry immersion effects on the mechanisms of metabolic-reflex regulation of hemodynamics during muscular work].

Science.gov (United States)

Bravyĭ, Ia R; Bersenev, E Iu; Missina, S S; Borovik, A S; Sharova, A P; Vinogradova, O L

2008-01-01

Effects of 4-d dry immersion on metabolic-reflex regulation of hemodynamics were evaluated during local static work (30% of maximum voluntary effort) of the talocrural extensors. One group of immersed test-subjects received low-frequency electrostimulation of leg muscles to offset the immersion effect on EMG of working muscles. Metabolic-reflex regulation was evaluated through comparison of cardiovascular responses to physical tests with and w/o post-exercise vascular occlusion. Immersion vaguely increased heart rate and reduced systolic arterial pressure in resting subjects; however, it did not have a distinct effect on arterial pressure and HR during muscular work or metabolic-reflex potentiation of hemodynamic shifts.

Necrotizing cellulitis with multiple abscesses on the leg caused by Serratia marcescens.

Science.gov (United States)

Hau, Estelle; Bouaziz, Jean-David; Lafaurie, Matthieu; Saussine, Anne; Masson, Vincent; Rausky, Jonathan; Bagot, Martine; Guibal, Fabien

2016-03-01

Serratia marcescens is an unusual cause of severe skin infection initially described in immunocompromised patients. We report a case of necrotizing cellulitis of the leg caused by S marcescens in a 68-year-old woman with diabetes mellitus and a history of chronic lymphoedema of the leg. We reviewed the literature and found 49 cases of severe skin infections from S marcescens that included 20 cases of necrotizing fasciitis (NF) as well as 29 cases of severe skin infections without NF (non-NF cases). Patients were immunocompromised in 59% to 70% of cases. The mortality rate was high in NF cases (60%) versus non-NF cases (3%). Surgery was required in 95% of NF cases and in 24% of non-NF cases. The other clinical manifestations of S marcescens skin infection reported in the literature included disseminated papular eruptions in patients infected with human immunodeficiency virus with folliculitis on the trunk. Serratia marcescens is naturally resistant to amoxicillin alone and amoxicillin associated with clavulanic acid. Broad-spectrum antibiotics are indicated to treat S marcescens skin infections, and surgery should be promptly considered in cases of severe skin infections if appropriate antibiotic therapy does not lead to rapid improvement.

Quantitation of stress/rest 201TI SPECT of the legs in the diagnosis of compartment-NT syndromes (CPS)

International Nuclear Information System (INIS)

Hayes, A.A.; Bower, G.D.; Pitstock, K.L.; Maguire, K.F.

1998-01-01

Full text: Compartment-NT syndrom (CPS) of the legs is considered to have an ischaemic basis related to muscle swelling and pressure increase in a muscle compartment (MC) during isotonic work. We decided to study selected patients where CPS was suspected with exercise 201 TI SPECT of the legs to better define their diagnoses. Eighteen patients with probable CPS reproduced their leg pain(s) during isotonic work, and 100 MBq of 201 TI was given i.v. during continued work and pain. Anterior 300 sec. planar and 360 degree, elliptical SPECT studies were acquired five minutes after stress and again four hours later. Quantitation of whole calf and regional MC uptake was attempted after the first five patients were assessed qualitatively. Ten patients were men and eight were women. The mean age was 30.8 y. Four had localised posterior and three had anterior pain with 11 having mixed and bilateral symptoms. Five patients had had a bone scan in the past and nine had MC pressure studies done within a month of study. Six patients had had previous decompressive surgery and seven patients had surgery after stress/rest studies. Four asymptomatic cardiac patients (''controls'') were imaged after their cardiac 201 TI studies and data used for comparison. Mean age of controls was 33 years. Generally even muscle uptake was seen on stress images with mean washout of 201 TI of 12% (7-23%) being calculated on delayed images of controls. Painful MCs with qualitative reduction in uptake after stress showed a mean increase in 201 TI of 25.7% (6-39%) on delayed imaging. Three patients with dramatic improvement in symptoms after surgery had shown a mean increase of 25.2% in delayed uptake in MCs on pre-operative studies. One patient showed washout of 11 and 15% from posterior MCs and had a poor response to subsequent surgery. Further clinical follow up in a large group of patients will be required to fully identify the place of Stress 201 TI imaging of the legs in this difficult group of

99mTc-HSA lymphoscintigraphy and leg edema after arterial reconstruction

International Nuclear Information System (INIS)

O-hara, Masaki; Seyama, Atsushi; Akimoto, Fumikazu; Nakamura, Takashi; Wakamatsu, Takahumi; Zempo, Nobuya; Esato, Kensuke

1992-01-01

To investigate the etiology of lower limb edema after arterial reconstruction, 12 patients (16 limbs) who underwent arterial reconstruction due to atherosclerosis obliterans were observed. There was no relationship between the severity of limb edema and serum factors (serum total proteins, albumin, BUN, and creatinine), ankle/brachial arterial pressure ratio, peripheral venous pressure or RI lymphoscintigraphy in the supine position. The lymphatic flow in RI lymphoscintigraphy at 3∼4 weeks after operation increased with statistically significant difference compared to the preoperative flow whether the patient was in the supine or upright position. Though there was no significant relationship between the severity of leg edema and postoperative lymphatic flow in the supine position, postoperative lymphatic flow in the upright position decreased as the severity of leg edema increased. Increased lymphatic flow in the follow-up period was associated with increased severity of leg edema in the upright position. It is concluded that postoperative leg edema is due to the damage to the lymphatic vessels during operation, and then the lymphatic channels cannot adapt to the increased lymphatic flow after the arterial reconstruction. (author)

Biomechanical study on axillary crutches during single-leg swing-through gait.

Science.gov (United States)

Goh, J C; Toh, S L; Bose, K

1986-08-01

This paper describes a kinetic and kinematic study on axillary crutches during one-leg swing-through gait. The primary objective is to evaluate the interplay of forces at the crutch and body interfaces and to relate them in the understanding of problems associated with the use of axillary crutches. Ten normal adult male subjects with simulated left leg impairment participated in the study. For data acquisition, the VICON kinematic system, a Kistler force plate and an instrumented crutch (with force transducers at the two upper struts close to the axillary bar and one near the crutch tip) were used. Results showed that the peak ground reaction force on the weight-bearing leg during lower limb stance increased by 21.6 percent bodyweight. The peak reaction force transmitted to the arm during crutch stance was 44.4 percent bodyweight. These increased loadings could be detrimental to patients with unsound weight-bearing leg and upper extremities respectively. When the crutches were used incorrectly, 34 percent bodyweight was carried by the underarm. This could cause undue pressure over the neurovascular structures at the axillary region.

High performance p-type segmented leg of misfit-layered cobaltite and half-Heusler alloy

International Nuclear Information System (INIS)

Hung, Le Thanh; Van Nong, Ngo; Snyder, G. Jeffrey; Viet, Man Hoang; Balke, Benjamin; Han, Li; Stamate, Eugen; Linderoth, Søren; Pryds, Nini

2015-01-01

Highlights: • p-type segmented leg of oxide and half-Heusler was for the first time demonstrated. • The maximum conversion efficiency reached a value of about 5%. • The results are among the highest reported values so far for oxide-based legs. • Oxide-based segmented leg is very promising for generating electricity. - Abstract: In this study, a segmented p-type leg of doped misfit-layered cobaltite Ca 2.8 Lu 0.15 Ag 0.05 Co 4 O 9+δ and half-Heusler Ti 0.3 Zr 0.35 Hf 0.35 CoSb 0.8 Sn 0.2 alloy was fabricated and characterized. The thermoelectric properties of single components, segmented leg, and the electrical contact resistance of the joint part were measured as a function of temperature. The output power generation characteristics of segmented legs were characterized in air under various temperature gradients, ΔT, with the hot side temperature up to 1153 K. At ΔT ≈ 756 K, the maximum conversion efficiency reached a value of ∼5%, which is about 65% of that expected from the materials without parasitic losses. The long-term stability investigation for two weeks at the hot and cold side temperatures of 1153/397 K shows that the segmented leg has good durability as a result of stable and low electrical resistance contacts

Mesenchymal stem cell in venous leg ulcer: An intoxicating therapy.

Science.gov (United States)

Athanerey, Anjali; Patra, Pradeep Kumar; Kumar, Awanish

2017-08-01

Venous leg ulcers (VLU) are a prevalent and reoccurring type of complicated wound, turning as a considerable public healthcare issue, with critical social and economic concern. There are both medical and surgical therapies to treat venous leg ulcers; however, a cure does not yet exist. Mesenchymal stem cells (MSC) are capable and proved of accelerating wound healing in vivo and their study with human chronic wounds is currently awaited. MSCs are a promising source of adult progenitor cells for cellular therapy and have been demonstrated to differentiate into various mesenchymal cell lineages. They have a crucial and integral role in native wound healing by regulating immune response and inflammation. Improved understanding of the cellular and molecular mechanisms at work in delayed wound healing compels to the development of cellular therapy in VLU. This review focuses on the current treatment option of VLU and further emphasizing the role of MSCs in accelerating the healing process. With further understanding of the mechanism of action of these cells in wound improvement and, the involvement of cytokines can also be revealed that could be used for the therapeutic purpose for VLU healing. Clinical uses of MSCs have been started already, and induced MSCs are surely a promising tool or compelling therapy for VLU. Copyright © 2017 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.

Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia) commercialized in France

OpenAIRE

Ohler, Annemarie; Nicolas, Violaine

2017-01-01

International audience; Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya ca...

Leg 201Tl-SPECT in chronic exertional compartment syndrome

International Nuclear Information System (INIS)

Elkadri, N.; Slim, I.; Blondet, C.; Choquet, Ph.; Constantinesco, A.; Lecocq, J.

2004-01-01

Leg 201 Tl-SPECT in chronic exertional compartment syndrome Background: The chronic exertional compartment syndrome is one of the most frequent origins regarding leg pain due to sport training. The diagnosis can be established by invasive compartment pressure measurement. The aim of this study is to evaluate the role that could have 201 Tl-SPECT for patients with suspicion of compartment syndrome. Patients and methods: 51 leg 201 Tl-SPECT exams were performed (exercise - and rest without reinjection) in 49 patients; 28 had compartment syndrome confirmed by pressure measurement. About 100 MBq of 201 Tl were injected during exercise, when pain appeared or at least after 25 minutes exercise. We studied mean percentages of level uptake for each compartment, referred to the maximal uptake of both legs. Results: 47 compartments were concerned by compartment syndrome and 361 compartments were not. Scintigraphic patterns in compartments are reversible ischaemia (45%), uptake stability (36%) or reverse redistribution (19%); these patterns are not linked to compartment syndrome. However, there is a significant difference of rest 201 Tl level uptake between compartments with and without compartment syndrome and a significant correlation between muscular pressure measurement and rest level uptake. Conclusion: 201 Tl-SPECT shows that only ischaemia does not explain compartment syndrome. Moreover, it allows to predict pressure variation during exercise but it does not offer any interest in order to select patients for muscular invasive pressure measurement. (author)

Limb symmetry during double-leg squats and single-leg squats on land and in water in adults with long-standing unilateral anterior knee pain; a cross sectional study.

Science.gov (United States)

Severin, Anna C; Burkett, Brendan J; McKean, Mark R; Wiegand, Aaron N; Sayers, Mark G L

2017-01-01

The presence of pain during movement typically results in changes in technique. However, the physical properties of water, such as flotation, means that water-based exercise may not only reduce compensatory movement patterns but also allow pain sufferers to complete exercises that they are unable to perform on land. The purpose of this study was to assess bilateral kinematics during double-leg squats and single-leg squats on land and in water in individuals with unilateral anterior knee pain. A secondary aim was to quantify bilateral asymmetry in both environments in affected and unaffected individuals using a symmetry index. Twenty individuals with unilateral knee pain and twenty healthy, matched controls performed body weight double- and single-leg squats in both environments while inertial sensors (100 Hz) recorded trunk and lower body kinematics. Repeated-measures statistics tested for environmental effects on movement depths and peak angles within the anterior knee pain group. Differences in their inter-limb symmetry in each environments was compared to the control group using analysis of variance tests. Water immersion allowed for greater movement depths during both exercises (double-leg squat: +7 cm, p  = 0.032, single-leg squat: +9 cm, p  = 0.002) for the knee pain group. The double-leg squat was symmetrical on land but water immersion revealed asymmetries in the lower body frontal plane movements. The single-leg squat revealed decreased hip flexion and frontal plane shank motions on the affected limb in both environments. Water immersion also affected the degree of lower limb asymmetry in both groups, with differences also showing between groups. Individuals with anterior knee pain achieved increased squat depth during both exercises whilst in water. Kinematic differences between the affected and unaffected limbs were often increased in water. Individuals with unilateral anterior knee pain appear to utilise different kinematics in the affected

Radiating leg pain and positive straight leg raising in spondylolysis in children.

Science.gov (United States)

Halperin, N; Copeliovitch, L; Schachner, E

1983-09-01

Three children presented with low back pain radiating to the leg and with spasm of the hamstring and paravertebral muscles. Since the pain could not be ascribed to trauma, it was necessary to exclude the presence of infection or tumors. All the signs--localization of the pain, tenderness on one side of the back, X-ray film findings of unilateral or bilateral spondylolysis, and localized positive bone scan--pointed to spondylolysis as the cause of pain. All three children exhibited symptoms resembling those found in the facet syndrome described by Mooney and Robertson.

Effects of wearing lower leg compression sleeves on locomotion economy.

Science.gov (United States)

Kurz, Eduard; Anders, Christoph

2018-09-01

The purpose of this investigation was to assess the effect of compression sleeves on muscle activation cost during locomotion. Twenty-two recreationally active men (age: 25 ± 3 years) ran on a treadmill at four different speeds (ordered sequence of 2.8, 3.3, 2.2, and 3.9 m/s). The tests were performed without (control situation, CON) and while wearing specially designed lower leg compression sleeves (SL). Myoelectric activity of five lower leg muscles (tibialis anterior, fibularis longus, lateral and medial head of gastrocnemius, and soleus) was captured using Surface EMG. To assess muscle activation cost, the cumulative muscle activity per distance travelled (CMAPD) of the CON and SL situations was determined. Repeated measures analyses of variance were performed separately for each muscle. The analyses revealed a reduced lower leg muscle activation cost with respect to test situation for SL for all muscles (p  0.18). The respective significant reductions of CMAPD values during SL ranged between 4% and 16% and were largest at 2.8 m/s. The findings presented point towards an improved muscle activation cost while wearing lower leg compression sleeves during locomotion that have potential to postpone muscle fatigue.

Neuro-Mechanics of Recumbent Leg Cycling in Post-Acute Stroke Patients.

Science.gov (United States)

Ambrosini, Emilia; De Marchis, Cristiano; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Monticone, Marco; Schmid, Maurizio; D'Alessio, Tommaso; Conforto, Silvia; Ferrante, Simona

2016-11-01

Cycling training is strongly applied in post-stroke rehabilitation, but how its modular control is altered soon after stroke has been not analyzed yet. EMG signals from 9 leg muscles and pedal forces were measured bilaterally during recumbent pedaling in 16 post-acute stroke patients and 12 age-matched healthy controls. Patients were asked to walk over a GaitRite mat and standard gait parameters were computed. Four muscle synergies were extracted through nonnegative matrix factorization in healthy subjects and patients unaffected legs. Two to four synergies were identified in the affected sides and the number of synergies significantly correlated with the Motricity Index (Spearman's coefficient = 0.521). The reduced coordination complexity resulted in a reduced biomechanical performance, with the two-module sub-group showing the lowest work production and mechanical effectiveness in the affected side. These patients also exhibited locomotor impairments (reduced gait speed, asymmetrical stance time, prolonged double support time). Significant correlations were found between cycling-based metrics and gait parameters, suggesting that neuro-mechanical quantities of pedaling can inform on walking dysfunctions. Our findings support the use of pedaling as a rehabilitation method and an assessment tool after stroke, mainly in the early phase, when patients can be unable to perform a safe and active gait training.

Principal component structure and sport-specific differences in the running one-leg vertical jump.

Science.gov (United States)

Laffaye, G; Bardy, B G; Durey, A

2007-05-01

The aim of this study is to identify the kinetic principal components involved in one-leg running vertical jumps, as well as the potential differences between specialists from different sports. The sample was composed of 25 regional skilled athletes who play different jumping sports (volleyball players, handball players, basketball players, high jumpers and novices), who performed a running one-leg jump. A principal component analysis was performed on the data obtained from the 200 tested jumps in order to identify the principal components summarizing the six variables extracted from the force-time curve. Two principal components including six variables accounted for 78 % of the variance in jump height. Running one-leg vertical jump performance was predicted by a temporal component (that brings together impulse time, eccentric time and vertical displacement of the center of mass) and a force component (who brings together relative peak of force and power, and rate of force development). A comparison made among athletes revealed a temporal-prevailing profile for volleyball players, and a force-dominant profile for Fosbury high jumpers. Novices showed an ineffective utilization of the force component, while handball and basketball players showed heterogeneous and neutral component profiles. Participants will use a jumping strategy in which variables related to either the magnitude or timing of force production will be closely coupled; athletes from different sporting backgrounds will use a jumping strategy that reflects the inherent demands of their chosen sport.

Prediction of Counter-Current Flow Limitation at Hot Leg Pipe During a Small-Break Loca

Energy Technology Data Exchange (ETDEWEB)

Jeong, H.Y. [Korea Electric Power Research Institute, Taejeon (Korea)

2001-07-01

The possibility of hot leg flooding during reflux condensation cooling after a small-break loss-of-coolant accident in a nuclear power plant is evaluated. The vapor and liquid velocities in hot leg and steam generator tubes are calculated during reflux condensation cooling with the accident scenarios of three typical break sizes, 0.13 %, 1.02 % and 10.19 % cold leg break. The effect of initial water level to counter-current flow limitation is taken into account. It is predicted that the hot leg flooding is precluded when all steam generators are available for heat removal. It is also shown the both hot leg flooding and SG flooding are possible under the operation of one steam generators. Therefore, it can be said that the occurrence of hot leg flooding under reflux condensation cooling is possible when the number of steam generators available for heat removal is limited. (author). 15 refs., 15 figs., 3 tabs.

Effects of music on work-rate distribution during a cycling time trial.

Science.gov (United States)

Atkinson, G; Wilson, D; Eubank, M

2004-11-01

Previous research work on the ergogenic effects of music has mainly involved constant power tests to exhaustion as dependent variables. Time trials are more externally valid than constant power tests, may be more reliable and allow the distribution of self-selected work-rate to be explored. We examined whether music improved starting, finishing and/or overall power during a 10-km cycling time trial, and whether heart rate and subjective responses to this time trial were altered by music. Sixteen participants performed two 10-km time trials on a Cybex cycle ergometer with, and without, the presence of a form of dance music known as "trance" (tempo = 142 beats x min (-1), volume at ear = 87 dB). Participants also completed the Brunel music rating inventory (BMRI) after each time trial in the music condition. The mean +/- SD time to complete the time trial was 1030 +/- 79 s in the music condition compared to 1052 +/- 77 s without music (95 % CI of difference = 10 to 34 s, p = 0.001). Nevertheless, ratings of perceived exertion were consistently (0.8 units) higher throughout the time trial with music (p music-induced increases in cycling speed and heart rate were observed in the first 3 km of the time trial. After completion of the BMRI, participants rated the "tempo" and "rhythm" of the music as more motivating than the "harmony" and "melody" aspects. These results suggest that music improves cycling speed mostly in the first few minutes of a 10-km time trial. In contrast to the findings of previous research, which suggested that music lowers perceived exertion at a constant work-rate, the participants in our time trials selected higher work-rates with music, whilst at the same time perceived these work-rates as being harder than without music.

Omnidirectional Wheel-Legged Hybrid Mobile Robot

Directory of Open Access Journals (Sweden)

István Vilikó

2015-06-01

Full Text Available The purpose of developing hybrid locomotion systems is to merge the advantages and to eliminate the disadvantages of different type of locomotion. The proposed solution combines wheeled and legged locomotion methods. This paper presents the mechatronic design approach and the development stages of the prototype.

Increased Leg Bone Mineral Density and Content During the Initial Years of College Sport.

Science.gov (United States)

Scerpella, John J; Buehring, Bjoern; Hetzel, Scott J; Heiderscheit, Bryan C

2018-04-01

Scerpella, JJ, Buehring, B, Hetzel, SJ, and Heiderscheit, BC. Increased leg bone mineral density and content during the initial years of college sport. J Strength Cond Res 32(4): 1123-1130, 2018-Bone mineral density (BMD) and bone mineral content (BMC) data are useful parameters for evaluating how training practices promote bone health. We used dual-energy X-ray absorptiometry (DXA) to longitudinally assess sport-specific growth in leg and total body BMD/BMC over the initial 2 years of collegiate training. Eighty-five Division 1 collegiate basketball, hockey, and soccer athletes (50 males and 35 females; age 19.0 [0.8] years) underwent annual DXA scans. Leg and total body BMD/BMC were compared within and across two 1-year intervals (periods 1 and 2) using repeated-measures analysis of variance, adjusting for age, sex, race, and sport. Leg BMD, leg BMC, and total body BMC all increased over period 1 (0.05 g·cm [p = 0.001], 0.07 kg [p = 0.002], and 0.19 kg [p BMC (p BMC (p = 0.005). Leg lean mass increased more during period 2 than period 1 (p = 0.018). Sports participation was the only significant predictor of change in leg BMD. Significant increases in both leg BMD and BMC were demonstrated over both 2-year periods, with greater gains during period 1. These gains highlight the importance of attentive training procedures, capitalizing on attendant physical benefits of increased BMD/BMC. Additional research in young adults, evaluating bone mass acquisition, will optimize performance and decrease risk of bone stress injury among collegiate athletes.

Painless Legs and Moving Toes as an Initial Presentation of Ischemic Stroke

Directory of Open Access Journals (Sweden)

Se Mi Oh

2009-05-01

Full Text Available Painless legs and moving toes is an unusual syndrome, which has not previously been reported as an initial presentation of ischemic stroke. We encountered a 78-year-old woman who developed dysarthria and involuntary movement of her left toes that was clinically regarded as painless legs and moving toes. These symptoms appeared abruptly and simultaneously as the initial symptoms of stroke, and improved gradually with conservative management by intravenous hydration for a month. We suggest that, in our case, a cortical brain lesion caused by ischemic stroke might be associated with the development of painless legs and moving toes.

A Powered Lower Limb Orthosis for Providing Legged Mobility in Paraplegic Individuals.

Science.gov (United States)

Quintero, Hugo A; Farris, Ryan J; Hartigan, Clare; Clesson, Ismari; Goldfarb, Michael

2011-01-01

This paper presents preliminary results on the development of a powered lower limb orthosis intended to provide legged mobility (with the use of a stability aid, such as forearm crutches) to paraplegic individuals. The orthosis contains electric motors at both hip and both knee joints, which in conjunction with ankle-foot orthoses, provides appropriate joint kinematics for legged locomotion. The paper describes the orthosis and the nature of the controller that enables the SCI patient to command the device, and presents data from preliminary trials that indicate the efficacy of the orthosis and controller in providing legged mobility.

Strength, body composition, and functional outcomes in the squat versus leg press exercises.

Science.gov (United States)

Rossi, Fabrício E; Schoenfeld, Brad J; Ocetnik, Skyler; Young, Jonathan; Vigotsky, Andrew; Contreras, Bret; Krieger, James W; Miller, Michael G; Cholewa, Jason

2018-03-01

The purpose of this study was to compare strength, body composition, and functional outcome measures following performance of the back squat, leg press, or a combination of the two exercises. Subjects were pair-matched based on initial strength levels and then randomly assigned to 1 of 3 groups: a squat-only group (SQ) that solely performed squats for the lower body; a leg press-only group (LP) that solely performed leg presses for the lower body, or a combined squat and leg press group (SQ-LP) that performed both squats and leg presses for the lower body. All other RT variables were held constant. The study period lasted 10 weeks with subjects performing 2 lower body workouts per week comprising 6 sets per session at loads corresponding to 8-12 RM with 90- to 120-second rest intervals. Results showed that SQ had greater transfer to maximal squat strength compared to the leg press. Effect sizes favored SQ and SQ-LP versus LP with respect to countermovement jump while greater effect sizes for dynamic balance were noted for SQ-LP and LP compared to SQ, although no statistical differences were noted between conditions. These findings suggest that both free weights and machines can improve functional outcomes, and that the extent of transfer may be specific to the given task.

One-leg balance is an important predictor of injurious falls in older persons.

Science.gov (United States)

Vellas, B J; Wayne, S J; Romero, L; Baumgartner, R N; Rubenstein, L Z; Garry, P J

1997-06-01

To test the hypothesis that one-leg balance is a significant predictor of falls and injurious falls. Analysis of data from a longitudinal cohort study. Healthy, community-living volunteers older than age 60 enrolled in the Albuquerque Falls Study and followed for 3 years (N = 316; mean age 73 years). Falls and injurious falls detected via reports every other month. Baseline measures of demographics, history, physical examination, Iowa Self Assessment Inventory, balance and gait assessment, and one-leg balance (ability to stand unassisted for 5 seconds on one leg). At baseline, 84.5% of subjects could perform one-leg balance. (Impairment was associated with older age and gait abnormalities.) Over the 3-year follow-up, 71% experienced a fall and 22% an injurious fall. The only independent significant predictor of all falls using logistic regression was age greater than 73. However, impaired one-leg balance was the only significant independent predictor of injurious falls (relative risk: 2.13; 95% CI: 1.04, 4.34; P = .03). One-leg balance appears to be a significant and easy-to-administer predictor of injurious falls, but not of all falls. In our study, it was the strongest individual predictor. However, no single factor seems to be accurate enough to be relied on as a sole predictor of fall risk or fall injury risk because so many diverse factors are involved in falling.

Ehlers-Danlos Syndrome Type VIII: A Rare Cause of Leg Ulcers in Young Patients

Directory of Open Access Journals (Sweden)

Sophie Ronceray

2013-01-01

Full Text Available Ehlers-Danlos syndrome type VIII (EDS-VIII is a very rare autosomal dominant disease characterized by early-onset periodontitis associated with features of Ehlers-Danlos syndrome. We report a 32-year-old man whose chronic leg ulcer led to the diagnosis of EDS-VIII. He had severe periodontitis with complete loss of permanent teeth and skin fragility with thin skin, atrophic scars, and brownish atrophic pretibial plaques. Leg ulcer is not a prominent feature of EDS-VIII. We suggest adding EDS-VIII to the list of rare diseases accounting for chronic leg ulcers, if this case report prompts others to report leg ulcers associated with EDS-VIII.

Cryoelectron Tomography of HIV-1 Envelope Spikes: Further Evidence for Tripod-Like Legs

Science.gov (United States)

Zhu, Ping; Winkler, Hanspeter; Chertova, Elena; Taylor, Kenneth A.; Roux, Kenneth H.

2008-01-01

A detailed understanding of the morphology of the HIV-1 envelope (Env) spike is key to understanding viral pathogenesis and for informed vaccine design. We have previously presented a cryoelectron microscopic tomogram (cryoET) of the Env spikes on SIV virions. Several structural features were noted in the gp120 head and gp41 stalk regions. Perhaps most notable was the presence of three splayed legs projecting obliquely from the base of the spike head toward the viral membrane. Subsequently, a second 3D image of SIV spikes, also obtained by cryoET, was published by another group which featured a compact vertical stalk. We now report the cryoET analysis of HIV-1 virion-associated Env spikes using enhanced analytical cryoET procedures. More than 2,000 Env spike volumes were initially selected, aligned, and sorted into structural classes using algorithms that compensate for the “missing wedge” and do not impose any symmetry. The results show varying morphologies between structural classes: some classes showed trimers in the head domains; nearly all showed two or three legs, though unambiguous three-fold symmetry was not observed either in the heads or the legs. Subsequently, clearer evidence of trimeric head domains and three splayed legs emerged when head and leg volumes were independently aligned and classified. These data show that HIV-1, like SIV, also displays the tripod-like leg configuration, and, unexpectedly, shows considerable gp41 leg flexibility/heteromorphology. The tripod-like model for gp41 is consistent with, and helps explain, many of the unique biophysical and immunological features of this region. PMID:19008954

Temperature and blood flow distribution in the human leg during passive heat stress.

Science.gov (United States)

Chiesa, Scott T; Trangmar, Steven J; González-Alonso, José

2016-05-01

The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. Copyright © 2016 the American Physiological Society.

Leg Length, Body Proportion, and Health: A Review with a Note on Beauty

Science.gov (United States)

Bogin, Barry; Varela-Silva, Maria Inês

2010-01-01

Decomposing stature into its major components is proving to be a useful strategy to assess the antecedents of disease, morbidity and death in adulthood. Human leg length (femur + tibia), sitting height (trunk length + head length) and their proportions, for example, (leg length/stature), or the sitting height ratio (sitting height/stature × 100), among others) are associated with epidemiological risk for overweight (fatness), coronary heart disease, diabetes, liver dysfunction and certain cancers. There is also wide support for the use of relative leg length as an indicator of the quality of the environment for growth during infancy, childhood and the juvenile years of development. Human beings follow a cephalo-caudal gradient of growth, the pattern of growth common to all mammals. A special feature of the human pattern is that between birth and puberty the legs grow relatively faster than other post-cranial body segments. For groups of children and youth, short stature due to relatively short legs (i.e., a high sitting height ratio) is generally a marker of an adverse environment. The development of human body proportions is the product of environmental x genomic interactions, although few if any specific genes are known. The HOXd and the short stature homeobox-containing gene (SHOX) are genomic regions that may be relevant to human body proportions. For example, one of the SHOX related disorders is Turner syndrome. However, research with non-pathological populations indicates that the environment is a more powerful force influencing leg length and body proportions than genes. Leg length and proportion are important in the perception of human beauty, which is often considered a sign of health and fertility. PMID:20617018

Similar acute physiological responses from effort and duration matched leg press and recumbent cycling tasks

Directory of Open Access Journals (Sweden)

James Steele

2018-02-01

Full Text Available The present study examined the effects of exercise utilising traditional resistance training (leg press or ‘cardio’ exercise (recumbent cycle ergometry modalities upon acute physiological responses. Nine healthy males underwent a within session randomised crossover design where they completed both the leg press and recumbent cycle ergometer conditions. Conditions were approximately matched for effort and duration (leg press: 4 × 12RM using a 2 s concentric and 3 s eccentric repetition duration controlled with a metronome, thus each set lasted  60 s; recumbent cycle ergometer: 4 × 60 s bouts using a resistance level permitting 80–100 rpm but culminating with being unable to sustain the minimum cadence for the final 5–10 s. Measurements included VO2, respiratory exchange ratio (RER, blood lactate, energy expenditure, muscle swelling, and electromyography. Perceived effort was similar between conditions and thus both were well matched with respect to effort. There were no significant effects by ‘condition’ in any of the physiological responses examined (all p > 0.05. The present study shows that, when both effort and duration are matched, resistance training (leg press and ‘cardio’ exercise (recumbent cycle ergometry may produce largely similar responses in VO2, RER, blood lactate, energy expenditure, muscle swelling, and electromyography. It therefore seems reasonable to suggest that both may offer a similar stimulus to produce chronic physiological adaptations in outcomes such as cardiorespiratory fitness, strength, and hypertrophy. Future work should look to both replicate the study conducted here with respect to the same, and additional physiological measures, and rigorously test the comparative efficacy of effort and duration matched exercise of differing modalities with respect to chronic improvements in physiological fitness.

Analysis of the Relationship between Elite Wrestlers’ Leg Strength and Balance Performance, and Injury History

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Sezen Çimen Polat

2018-04-01

Full Text Available The purpose of this study is to examine the correlation between leg power and balance performance in elite wrestlers and injury history. In the research group, there are 18 elite freestyle male wrestlers at the ages of 24.27 ± 3.18 years, with a height of 171.86 ± 5.44 cm and a body weight of 79.27 ± 11.16 kg. Information on the injury history of the athletes’ upper legs for the past year was collected via interviews with the club’s physiotherapist. Laboratory tests to measure performance assessed height, body weight, Y balance and isokinetic leg strength. Data obtained from the study are presented as mean and standard deviation. The test of normality was carried out by the Shapiro-Wilk test. The Pearson Correlation Test was performed for all parameters with normal distribution, and significance level was accepted as p < 0.05. It was found that there is a relationship between the wrestlers’ right leg ratio and hamstring strength and injury history. However, there is no statistically significant relationship between left leg hamstring, quadriceps, ratio, right leg quadriceps, or right and left leg balance performance, and injury history. The resulting data shows that the proportioning between hamstring and quadriceps muscles in freestyle wrestlers’ upper leg strength values is not ideal. This finding provides evidence that injury risk increases with the additional impact of loss of strength.

Leg coordination during turning on an extremely narrow substrate in a bug, Mesocerus marginatus (Heteroptera, Coreidae).

Science.gov (United States)

Frantsevich, Leonid I; Cruse, Holk

2005-10-01

The turning movement of a bug, Mesocerus marginatus, is observed when it walks upside-down below a horizontal beam and, at the end of the beam, performs a sharp turn by 180 degrees . The turn at the end of the beam is accomplished in three to five steps, without strong temporal coordination among legs. During the stance, leg endpoints (tarsi) run through rounded trajectories, rotating to the same side in all legs. During certain phases of the turn, a leg is strongly depressed and the tarsus crosses the midline. Swing movements rotate to the same side as do leg endpoints in stance, in strong contrast to the typical swing movements found in turns or straight walk on a flat surface. Terminal location is found after the search through a trajectory that first moves away from the body and then loops back to find substrate. When a leg during stance has crossed the midline, in the following swing movement the leg may move even stronger on the contralateral side, i.e. is stronger depressed, in contrast to swing movements in normal walking, where the leg is elevated. These results suggest that the animals apply a different control strategy compared to walking and turning on a flat surface.

The Effect of Rehearsal Rate and Memory Load on Verbal Working Memory

OpenAIRE

Fegen, David; Buchsbaum, Bradley R.; D’Esposito, Mark

2014-01-01

While many neuroimaging studies have investigated verbal working memory (WM) by manipulating memory load, the subvocal rehearsal rate at these various memory loads has generally been left uncontrolled. Therefore, the goal of this study was to investigate how mnemonic load and the rate of subvocal rehearsal modulate patterns of activity in the core neural circuits underlying verbal working memory. Using fMRI in healthy subjects, we orthogonally manipulated subvocal rehearsal rate and memory lo...

Counter-current flow limitation at hot leg pipe during reflux condensation cooling after small-break LOCA

International Nuclear Information System (INIS)

Jeong, Hae Yong; Ha, Sang Jun; Jo, Yung Jo; Jun, Hwang Yong

1999-01-01

The possibility of hot leg flooding is evaluated in case of a small-break loss-of-coolant accident in Korean Next Generation Reactor (KNGR) operating at the core power of 3983 MW normally. The vapor and liquid velocities in hot leg and steam generator tubes are calculated during reflux condensation cooling with the accident scenarios of three typical break sizes, 0.13 %, 1.02 % and 10.19 % cold leg break. The calculated results are compared with the existing flooding correlations. It is predicted that the hot leg flooding is excluded when two steam generators are available. It is also shown that the possibility of hot leg flooding under the operation with one steam generator is very low. Therefore, it can be said that the occurrence of hot leg flooding is unexpected when the reflux condensation cooling is maintained in steam generator tubes

Dynamic stability of running: The effects of speed and leg amputations on the maximal Lyapunov exponent

International Nuclear Information System (INIS)

Look, Nicole; Arellano, Christopher J.; Grabowski, Alena M.; Kram, Rodger; McDermott, William J.; Bradley, Elizabeth

2013-01-01

In this paper, we study dynamic stability during running, focusing on the effects of speed, and the use of a leg prosthesis. We compute and compare the maximal Lyapunov exponents of kinematic time-series data from subjects with and without unilateral transtibial amputations running at a wide range of speeds. We find that the dynamics of the affected leg with the running-specific prosthesis are less stable than the dynamics of the unaffected leg and also less stable than the biological legs of the non-amputee runners. Surprisingly, we find that the center-of-mass dynamics of runners with two intact biological legs are slightly less stable than those of runners with amputations. Our results suggest that while leg asymmetries may be associated with instability, runners may compensate for this effect by increased control of their center-of-mass dynamics

Analysis of Foot Slippage Effects on an Actuated Spring-Mass Model of Dynamic Legged Locomotion

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Yizhar Or

2016-04-01

Full Text Available The classical model of spring-loaded inverted pendulum (SLIP and its extensions have been widely accepted as a simple description of dynamic legged locomotion at various scales in humans, legged robots and animals. Similar to the majority of models in the literature, the SLIP model assumes ideal sticking contact of the foot. However, there are practical scenarios of low ground friction that causes foot slippage, which can have a significant influence on dynamic behaviour. In this work, an extension of the SLIP model with two masses and torque actuation is considered, which accounts for possible slippage under Coulomb's friction law. The hybrid dynamics of this model is formulated and numerical simulations under representative parameter values reveal several types of stable periodic solutions with stick-slip transitions. Remarkably, it is found that slippage due to low friction can sometimes increase average speed and improve energetic efficiency by significantly reducing the mechanical cost of transport.

Effects of respiratory muscle work on respiratory and locomotor blood flow during exercise.

Science.gov (United States)

Dominelli, Paolo B; Archiza, Bruno; Ramsook, Andrew H; Mitchell, Reid A; Peters, Carli M; Molgat-Seon, Yannick; Henderson, William R; Koehle, Michael S; Boushel, Robert; Sheel, A William

2017-11-01

What is the central question of this study? Does manipulation of the work of breathing during high-intensity exercise alter respiratory and locomotor muscle blood flow? What is the main finding and its importance? We found that when the work of breathing was reduced during exercise, respiratory muscle blood flow decreased, while locomotor muscle blood flow increased. Conversely, when the work of breathing was increased, respiratory muscle blood flow increased, while locomotor muscle blood flow decreased. Our findings support the theory of a competitive relationship between locomotor and respiratory muscles during intense exercise. Manipulation of the work of breathing (WOB) during near-maximal exercise influences leg blood flow, but the effects on respiratory muscle blood flow are equivocal. We sought to assess leg and respiratory muscle blood flow simultaneously during intense exercise while manipulating WOB. Our hypotheses were as follows: (i) increasing the WOB would increase respiratory muscle blood flow and decrease leg blood flow; and (ii) decreasing the WOB would decrease respiratory muscle blood flow and increase leg blood flow. Eight healthy subjects (n = 5 men, n = 3 women) performed a maximal cycle test (day 1) and a series of constant-load exercise trials at 90% of peak work rate (day 2). On day 2, WOB was assessed with oesophageal balloon catheters and was increased (via resistors), decreased (via proportional assist ventilation) or unchanged (control) during the trials. Blood flow was assessed using near-infrared spectroscopy optodes placed over quadriceps and the sternocleidomastoid muscles, coupled with a venous Indocyanine Green dye injection. Changes in WOB were significantly and positively related to changes in respiratory muscle blood flow (r = 0.73), whereby increasing the WOB increased blood flow. Conversely, changes in WOB were significantly and inversely related to changes in locomotor blood flow (r = 0.57), whereby decreasing the

VenUS I: a randomised controlled trial of two types of bandage for treating venous leg ulcers.

Science.gov (United States)

Iglesias, C; Nelson, E A; Cullum, N A; Torgerson, D J

2004-07-01

To compare the clinical and cost-effectiveness of two different compression bandages for the healing of venous leg ulcers. A pragmatic, randomised controlled trial with an economic evaluation. Community, district nurse-led services; community leg ulcer clinics; hospital leg ulcer clinics with community outreach. A range of urban and rural settings in England and Scotland. Patients with a venous leg ulcer of at least 1-week's duration, at least 1 cm in length or width and an ankle:brachial pressure index of at least 0.8. The four-layer bandage (4LB) (which is multilayer elastic compression) compared with the short-stretch bandage (SSB) (multilayer, inelastic compression). The primary end-point was complete healing of all the ulcers on the trial leg. Secondary outcomes were the proportion of patients healed at 12 and 24 weeks, rate of recurrence, costs of leg ulcer treatment and quality of life. Between April 1999 and December 2000 the trial recruited 387 people aged from 23 to 97 years at trial entry. The majority of patients in this trial (82%; 316/387) had a reference ulcer of area bandage groups, the distribution of the cumulative times to healing of individuals in the two trial groups was compared using the log-rank test. The difference in the distribution of cumulative healing times between the individuals in the two groups was not statistically significant at the 5% level. Adjusting for the effects of variables which may influence healing (centre, baseline ulcer area, duration, episodes, ankle mobility, weight) in a Cox proportional hazards model, a statistically significant treatment effect in favour of the 4LB was identified. At any point in time, the probability of healing for individuals in the SSB treatment arm is significantly lower than that for people treated with the 4LB. Our base case economic analysis showed that the 4LB is the dominant strategy, that is, it is associated with a greater health benefit and lower costs than the SSB, although the

How to determine leg dominance: The agreement between self-reported and observed performance in healthy adults

OpenAIRE

van Melick, Nicky; Meddeler, Bart M.; Hoogeboom, Thomas J.; Nijhuis-van der Sanden, Maria W. G.; van Cingel, Robert E. H.

2017-01-01

CONTEXT: Since decades leg dominance is suggested to be important in rehabilitation and return to play in athletes with anterior cruciate ligament injuries. However, an ideal method to determine leg dominance in relation to task performance is still lacking. OBJECTIVE: To test the agreement between self-reported and observed leg dominance in bilateral mobilizing and unilateral stabilizing tasks, and to assess whether the dominant leg switches between bilateral mobilizing tasks and unilateral ...

Proprioceptive Actuation Design for Dynamic Legged locomotion

Science.gov (United States)

Kim, Sangbae; Wensing, Patrick; Biomimetic Robotics Lab Team

Designing an actuator system for highly-dynamic legged locomotion exhibited by animals has been one of the grand challenges in robotics research. Conventional actuators designed for manufacturing applications have difficulty satisfying challenging requirements for high-speed locomotion, such as the need for high torque density and the ability to manage dynamic physical interactions. It is critical to introduce a new actuator design paradigm and provide guidelines for its incorporation in future mobile robots for research and industry. To this end, we suggest a paradigm called proprioceptive actuation, which enables highly- dynamic operation in legged machines. Proprioceptive actuation uses collocated force control at the joints to effectively control contact interactions at the feet under dynamic conditions. In the realm of legged machines, this paradigm provides a unique combination of high torque density, high-bandwidth force control, and the ability to mitigate impacts through backdrivability. Results show that the proposed design provides an impact mitigation factor that is comparable to other quadruped designs with series springs to handle impact. The paradigm is shown to enable the MIT Cheetah to manage the application of contact forces during dynamic bounding, with results given down to contact times of 85ms and peak forces over 450N. As a result, the MIT Cheetah achieves high-speed 3D running up to 13mph and jumping over an 18-inch high obstacle. The project is sponsored by DARPA M3 program.

Asterixis in the leg induced by anterior cerebral artery infarction.

Science.gov (United States)

Sunwoo, Mun Kyung; Jang, Hyun-Soon; Roh, Sook Young; Yoo, Hyun Jung; Jeong, Eun Hye; Kim, Byung-Su; Choe, Yeo Reum; Lee, Ko-Eun

2016-06-01

Asterixis commonly occurs in a patient with metabolic encephalopathy, whereas focal brain lesions such as thalamus, cerebellum, or frontal area also cause focal or unilateral asterixis in the arms. We report a novel case of asterixis in the leg after unilateral anterior cerebral artery territory infarction. A 76-year-old man was admitted with sudden-onset mild right leg weakness and postural instability due to knee buckling. He was diagnosed with ischemic stroke in the left prefrontal area and cingulated gyrus by brain magnetic imaging. Needle electromyography of the right vastus lateralis muscle while standing showed intermittent periods of EMG silence, consistent with asterixis. There were no abnormal involuntary movements in the upper extremities. This case suggests that gait disturbance or postural instability after structural lesions in the prefrontal area may be directly related to asterixis in the leg, not in the arm associated with postural failure.

Leg Movement Activity During Sleep in Adults With Attention-Deficit/Hyperactivity Disorder

Directory of Open Access Journals (Sweden)

Corrado Garbazza

2018-05-01

Full Text Available Objectives: To conduct a first detailed analysis of the pattern of leg movement (LM activity during sleep in adult subjects with Attention-Deficit/Hyperactivity Disorder (ADHD compared to healthy controls.Methods: Fifteen ADHD patients and 18 control subjects underwent an in-lab polysomnographic sleep study. The periodic character of LMs was evaluated with established markers of “periodicity,” i.e., the periodicity index, intermovement intervals, and time distribution of LM during sleep, in addition to standard parameters such as the periodic leg movement during sleep index (PLMSI and the periodic leg movement during sleep arousal index (PLMSAI. Subjective sleep and psychiatric symptoms were assessed using several, self-administered, screening questionnaires.Results: Objective sleep parameters from the baseline night did not significantly differ between ADHD and control subjects, except for a longer sleep latency (SL, a longer duration of the periodic leg movements during sleep (PLMS in REM sleep and a higher PLMSI also in REM sleep. Data from the sleep questionnaires showed perception of poor sleep quality in ADHD patients.Conclusions: Leg movements during sleep in ADHD adults are not significantly more frequent than in healthy controls and the nocturnal motor events do not show an increased periodicity in these patients. The non-periodic character of LMs in ADHD has already been shown in children and seems to differentiate ADHD from other pathophysiological related conditions like restless legs syndrome (RLS or periodic limb movement disorder (PLMD. The reduced subjective sleep quality reported by ADHD adults contrasted with the normal objective polysomnographic parameters, which could suggest a sleep-state misperception in these individuals or more subtle sleep abnormalities not picked up by the traditional sleep staging.

Mechatronics by Analogy and Application to Legged Locomotion

Science.gov (United States)

Ragusila, Victor

A new design methodology for mechatronic systems, dubbed as Mechatronics by Analogy (MbA), is introduced and applied to designing a leg mechanism. The new methodology argues that by establishing a similarity relation between a complex system and a number of simpler models it is possible to design the former using the analysis and synthesis means developed for the latter. The methodology provides a framework for concurrent engineering of complex systems while maintaining the transparency of the system behaviour through making formal analogies between the system and those with more tractable dynamics. The application of the MbA methodology to the design of a monopod robot leg, called the Linkage Leg, is also studied. A series of simulations show that the dynamic behaviour of the Linkage Leg is similar to that of a combination of a double pendulum and a spring-loaded inverted pendulum, based on which the system kinematic, dynamic, and control parameters can be designed concurrently. The first stage of Mechatronics by Analogy is a method of extracting significant features of system dynamics through simpler models. The goal is to determine a set of simpler mechanisms with similar dynamic behaviour to that of the original system in various phases of its motion. A modular bond-graph representation of the system is determined, and subsequently simplified using two simplification algorithms. The first algorithm determines the relevant dynamic elements of the system for each phase of motion, and the second algorithm finds the simple mechanism described by the remaining dynamic elements. In addition to greatly simplifying the controller for the system, using simpler mechanisms with similar behaviour provides a greater insight into the dynamics of the system. This is seen in the second stage of the new methodology, which concurrently optimizes the simpler mechanisms together with a control system based on their dynamics. Once the optimal configuration of the simpler system is

The RiSE climbing robot: body and leg design

Science.gov (United States)

Saunders, A.; Goldman, D. I.; Full, R. J.; Buehler, M.

2006-05-01

The RiSE robot is a biologically inspired, six legged climbing robot, designed for general mobility in scansorial (vertical walls, horizontal ledges, ground level) environments. It exhibits ground reaction forces that are similar to animal climbers and does not rely on suction, magnets or other surface-dependent specializations to achieve adhesion and shear force. We describe RiSE's body and leg design as well as its electromechanical, communications and computational infrastructure. We review design iterations that enable RiSE to climb 90° carpeted, cork covered and (a growing range of) stucco surfaces in the quasi-static regime.

Water striders adjust leg movement speed to optimize takeoff velocity for their morphology

Science.gov (United States)

Yang, Eunjin; Son, Jae Hak; Lee, Sang-Im; Jablonski, Piotr G.; Kim, Ho-Young

2016-12-01

Water striders are water-walking insects that can jump upwards from the water surface. Quick jumps allow striders to avoid sudden dangers such as predators' attacks, and therefore their jumping is expected to be shaped by natural selection for optimal performance. Related species with different morphological constraints could require different jumping mechanics to successfully avoid predation. Here we show that jumping striders tune their leg rotation speed to reach the maximum jumping speed that water surface allows. We find that the leg stroke speeds of water strider species with different leg morphologies correspond to mathematically calculated morphology-specific optima that maximize vertical takeoff velocity by fully exploiting the capillary force of water. These results improve the understanding of correlated evolution between morphology and leg movements in small jumping insects, and provide a theoretical basis to develop biomimetic technology in semi-aquatic environments.

Multiple Chaotic Central Pattern Generators with Learning for Legged Locomotion and Malfunction Compensation

DEFF Research Database (Denmark)

Ren, Guanjiao; Chen, Weihai; Dasgupta, Sakyasingha

2015-01-01

on a simulated annealing algorithm. In a normal situation, the CPGs synchronize and their dynamics are identical. With leg malfunction or disability, the CPGs lose synchronization leading to independent dynamics. In this case, the learning mechanism is applied to automatically adjust the remaining legs...... in a physical simulation of a quadruped as well as a hexapod robot and finally in a real six-legged walking machine called AMOSII. The experimental results presented here reveal that using multiple CPGs with learning is an effective approach for adaptive locomotion generation where, for instance, different body...... chaotic CPG controller has difficulties dealing with leg malfunction. Specifically, in the scenarios presented here, its movement permanently deviates from the desired trajectory. To address this problem, we extend the single chaotic CPG to multiple CPGs with learning. The learning mechanism is based...

Prevalence of restless legs symptoms according to depressive symptoms and depression type: a cross-sectional study.

Science.gov (United States)

Auvinen, Piritta; Mäntyselkä, Pekka; Koponen, Hannu; Kautiainen, Hannu; Korniloff, Katariina; Ahonen, Tiina; Vanhala, Mauno

2018-01-01

Restless legs syndrome is a sensorimotor disorder and it is associated with several other diseases especially mental illnesses. To analyze the relationship between the symptoms of restless legs syndrome and the severity of depressive symptoms and the prevalence of restless legs symptoms in depression subtypes. A cross-sectional study of primary care patients in the Central Finland Hospital District. The prevalence of restless legs symptoms was studied in 706 patients with increased depressive symptoms and 426 controls without a psychiatric diagnosis by using a structured questionnaire. The depressive symptoms were evaluated with the Beck Depression Inventory (BDI) and the psychiatric diagnosis was confirmed by means of a diagnostic interview (Mini-International Neuropsychiatric Interview). The subjects with increased depressive symptoms were divided into three groups (subjects with depressive symptoms without a depression diagnosis, melancholic depression and non-melancholic depression). In the whole study population, the prevalence of restless legs symptoms increased with the severity of depressive symptoms. The prevalence of restless legs symptoms was highest in the melancholic and non-melancholic depressive patients (52 and 46%, respectively) and then in subjects with depressive symptoms without a depression diagnosis (43.4%), but the prevalence was also substantial (24.6%) in subjects without a psychiatric diagnosis. Restless legs symptoms are very common in primary care among subjects with depression, regardless of the depression type. The prevalence of restless legs symptoms increased with increasing severity of depressive symptoms, regardless of the diagnosis. These findings should be considered in clinical evaluation and treatment of patients visiting their physician due to restless legs or depressive symptoms.

Association between Thigh Muscle Volume and Leg Muscle Power in Older Women.

Directory of Open Access Journals (Sweden)

Ulrich Lindemann

Full Text Available The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628, leg push power (r = 0.550, isometric quadriceps strength (r = 0.442, hand grip strength (r = 0.367, fast gait speed (r = 0.291, habitual gait speed (r = 0.256, body mass index (r = 0.411 and age (r = -0.392. Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

Template model inspired leg force feedback based control can assist human walking.

Science.gov (United States)

Zhao, Guoping; Sharbafi, Maziar; Vlutters, Mark; van Asseldonk, Edwin; Seyfarth, Andre

2017-07-01

We present a novel control approach for assistive lower-extremity exoskeletons. In particular, we implement a virtual pivot point (VPP) template model inspired leg force feedback based controller on a lower-extremity powered exoskeleton (LOPES II) and demonstrate that it can effectively assist humans during walking. It has been shown that the VPP template model is capable of stabilizing the trunk and reproduce a human-like hip torque during the stance phase of walking. With leg force and joint angle feedback inspired by the VPP template model, our controller provides hip and knee torque assistance during the stance phase. A pilot experiment was conducted with four healthy subjects. Joint kinematics, leg muscle electromyography (EMG), and metabolic cost were measured during walking with and without assistance. Results show that, for 0.6 m/s walking, our controller can reduce leg muscle activations, especially for the medial gastrocnemius (about 16.0%), while hip and knee joint kinematics remain similar to the condition without the controller. Besides, the controller also reduces 10% of the net metabolic cost during walking. This paper demonstrates walking assistance benefits of the VPP template model for the first time. The support of human walking is achieved by a force feedback of leg force applied to the control of hip and knee joints. It can help us to provide a framework for investigating walking assistance control in the future.

Pelvic movement strategies and leg extension power in patients with end-stage medial compartment knee osteoarthritis

DEFF Research Database (Denmark)

Kierkegaard, Signe; Jørgensen, Peter Bo; Dalgas, Ulrik

2015-01-01

advancing functional tasks, and how these strategies are associated with leg extension power. The aim of the study was to investigate pelvic movement strategies and leg extension power in patients with end-stage medial compartment knee osteoarthritis compared with controls. MATERIALS AND METHODS: 57...... patients (mean age 65.6 years) scheduled for medial uni-compartmental knee arthroplasty, and 29 age and gender matched controls were included in this cross-sectional study. Leg extension power was tested with the Nottingham Leg Extension Power-Rig. Pelvic range of motion was derived from an inertia......-based measurement unit placed over the sacrum bone during walking, stair climbing and stepping. RESULTS: Patients had lower leg extension power than controls (20-39 %, P

Comparison of kinematic and dynamic leg trajectory optimization techniques for biped robot locomotion

Science.gov (United States)

Khusainov, R.; Klimchik, A.; Magid, E.

2017-01-01

The paper presents comparison analysis of two approaches in defining leg trajectories for biped locomotion. The first one operates only with kinematic limitations of leg joints and finds the maximum possible locomotion speed for given limits. The second approach defines leg trajectories from the dynamic stability point of view and utilizes ZMP criteria. We show that two methods give different trajectories and demonstrate that trajectories based on pure dynamic optimization cannot be realized due to joint limits. Kinematic optimization provides unstable solution which can be balanced by upper body movement.

Reconstruction of core inlet temperature distribution by cold leg temperature measurements

International Nuclear Information System (INIS)

Saarinen, S.; Antila, M.

2010-01-01

The reduced core of Loviisa NPP contains 33 thermocouple measurements measuring the core inlet temperature. Currently, these thermocouple measurements are not used in determining the inlet temperature distribution. The average of cold leg temperature measurements is used as inlet temperature for each fuel assembly. In practice, the inlet temperature distribution is not constant. Thus, using a constant inlet temperature distribution induces asymmetries in the measured core power distribution. Using a more realistic inlet temperature distribution would help us to reduce virtual asymmetries of the core power distribution and increase the thermal margins of the core. The thermocouples at the inlet cannot be used directly to measure the inlet temperature accurately because the calibration of the thermocouples that is done at hot zero power conditions is no longer valid at full power, when there is temperature change across the core region. This is due to the effect of neutron irradiation on the Seebeck coefficient of the thermocouple wires. Therefore, we investigate in this paper a method to determine the inlet temperature distribution based on the cold leg temperature measurements. With this method we rely on the assumption that although the core inlet thermocouple measurements do not measure the absolute temperature accurately they do measure temperature changes with sufficient accuracy particularly in big disturbances. During the yearly testing of steam generator safety valves we observe a large temperature increase up to 12 degrees in the cold leg temperature. The change in the temperature of one of the cold legs causes a local disturbance in the core inlet temperature distribution. Using the temperature changes observed in the inlet thermocouple measurements we are able to fit six core inlet temperature response functions, one for each cold leg. The value of a function at an assembly inlet is determined only by the corresponding cold leg temperature disturbance

Stiffness characteristics of compliant three segment leg with the self-stable region in slow and fast running

Energy Technology Data Exchange (ETDEWEB)

Kwak, Oh Seok; Ha, Sung Mok; Lee, Dong Ha [Convergence Research Center for WellnessDaegu Gyeongbuk Institute of Science and TechnologyDaegu (Korea, Republic of)

2016-12-15

In this paper, we propose the stiffness characteristics of compliant three segment leg that can have a self-stable region in slow and fast running. This proposition can contribute to reducing the control effort and enhancing the locomotion energy efficiency for the compliant three segment legged robot in slow and fast running. Previous research indicated that the running self-stable region of the spring-mass system is located in a relatively fast running region and that of the two segment leg is located in a relatively slow running region. In this paper, we analyze the stiffness characteristics of the spring-mass system and the two segment leg to explain the previous research results. From this analysis, we propose the stiffness characteristics of the compliant three segment leg with a self-stable region in slow and fast running. We further design the compliant three segment leg based on this proposition and check its structural stability. We examine the running self-stable region of this compliant three segment leg to determine whether it has a self-stable region in slow and fast running. We also examine the walking self-stable region of this compliant three segment leg.

EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of Americium in a USTUR leg phantom

International Nuclear Information System (INIS)

Lopez, M. A.; Broggio, D.; Capello, K.; Cardenas-Mendez, E.; El-Faramawy, N.; Franck, D.; James, A. C.; Kramer, G. H.; Lacerenza, G.; Lynch, T. P.; Navarro, J. F.; Navarro, T.; Perez, B.; Ruehm, W.; Tolmachev, S. Y.; Weitzenegger, E.

2011-01-01

A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here. (authors)

Applying a pelvic corrective force induces forced use of the paretic leg and improves paretic leg EMG activities of individuals post-stroke during treadmill walking.

Science.gov (United States)

Hsu, Chao-Jung; Kim, Janis; Tang, Rongnian; Roth, Elliot J; Rymer, William Z; Wu, Ming

2017-10-01

To determine whether applying a mediolateral corrective force to the pelvis during treadmill walking would enhance muscle activity of the paretic leg and improve gait symmetry in individuals with post-stroke hemiparesis. Fifteen subjects with post-stroke hemiparesis participated in this study. A customized cable-driven robotic system based over a treadmill generated a mediolateral corrective force to the pelvis toward the paretic side during early stance phase. Three different amounts of corrective force were applied. Electromyographic (EMG) activity of the paretic leg, spatiotemporal gait parameters and pelvis lateral displacement were collected. Significant increases in integrated EMG of hip abductor, medial hamstrings, soleus, rectus femoris, vastus medialis and tibialis anterior were observed when pelvic corrective force was applied, with pelvic corrective force at 9% of body weight inducing greater muscle activity than 3% or 6% of body weight. Pelvis lateral displacement was more symmetric with pelvic corrective force at 9% of body weight. Applying a mediolateral pelvic corrective force toward the paretic side may enhance muscle activity of the paretic leg and improve pelvis displacement symmetry in individuals post-stroke. Forceful weight shift to the paretic side could potentially force additional use of the paretic leg and improve the walking pattern. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

ODP Leg 210 Drills the Newfoundland Margin in the Newfoundland-Iberia Non-Volcanic Rift

Science.gov (United States)

Tucholke, B. E.; Sibuet, J.

2003-12-01

The final leg of the Ocean Drilling Project (Leg 210, July-September 2003) was devoted to studying the history of rifting and post-rift sedimentation in the Newfoundland-Iberia rift. For the first time, drilling was conducted in the Newfoundland Basin along a transect conjugate to previous drill sites on the Iberia margin (Legs 149 and 173) to obtain data on a complete `non-volcanic' rift system. The prime site during this leg (Site 1276) was drilled in the transition zone between known continental crust and known oceanic crust at chrons M3 and younger. Extensive geophysical work and deep-sea drilling have shown that this transition-zone crust on the conjugate Iberia margin is exhumed continental mantle that is strongly serpentinized in its upper part. Transition-zone crust on the Newfoundland side, however, is typically a kilometer or more shallower and has much smoother topography, and seismic refraction data suggest that the crust may be thin (about 4 km) oceanic crust. A major goal of Site 1276 was to investigate these differences by sampling basement and a strong, basinwide reflection (U) overlying basement. Site 1276 was cored from 800 to 1737 m below seafloor with excellent recovery (avg. 85%), bottoming in two alkaline diabase sills >10 m thick that are estimated to be 100-200 meters above basement. The sills have sedimentary contacts that show extensive hydrothermal metamorphism. Associated sediment structural features indicate that the sills were intruded at shallow levels within highly porous sediments. The upper sill likely is at the level of the U reflection, which correlates with lower Albian - uppermost Aptian(?) fine- to coarse-grained gravity-flow deposits. Overlying lower Albian to lower Oligocene sediments record paleoceanographic conditions similar to those on the Iberia margin and in the main North Atlantic basin, including deposition of `black shales'; however, they show an extensive component of gravity-flow deposits throughout.

An Ultralightweight and Living Legged Robot.

Science.gov (United States)

Vo Doan, Tat Thang; Tan, Melvin Y W; Bui, Xuan Hien; Sato, Hirotaka

2018-02-01

In this study, we describe the most ultralightweight living legged robot to date that makes it a strong candidate for a search and rescue mission. The robot is a living beetle with a wireless electronic backpack stimulator mounted on its thorax. Inheriting from the living insect, the robot employs a compliant body made of soft actuators, rigid exoskeletons, and flexure hinges. Such structure would allow the robot to easily adapt to any complex terrain due to the benefit of soft interface, self-balance, and self-adaptation of the insect without any complex controller. The antenna stimulation enables the robot to perform not only left/right turning but also backward walking and even cessation of walking. We were also able to grade the turning and backward walking speeds by changing the stimulation frequency. The power required to drive the robot is low as the power consumption of the antenna stimulation is in the order of hundreds of microwatts. In contrast to the traditional legged robots, this robot is of low cost, easy to construct, simple to control, and has ultralow power consumption.

Restless legs syndrome in hemodialysis patients

Directory of Open Access Journals (Sweden)

Shahram Rafie

2016-01-01

Full Text Available Restless legs syndrome (RLS is a neurological disorder characterized by uncomfortable sensation of paresthesia in legs that subsequently causes involuntary and continuous movement of the lower limbs, especially at rest. Its prevalence in hemodialysis is more than that in the general population. Different risk factors have been suggested for RLS. We studied the prevalence and risk factors of RLS in 137 hemodialysis patients followed up at our center. The patients completed at least three months on dialysis and fulfilled four criteria for the diagnosis of RLS. We compared the patients with and without RLS, and the odds ratios (ORs were estimated by the logistic regression models. The prevalence of RLS was 36.5% in the study patients. Among the variables, diabetes was the only predicting factor for the development of RLS. The diabetic patients may be afflicted with RLS 2.25 times more than the non-diabetics. Women developed severe RLS 5.23 times more than men. Neurodegeneration, decrease in dopamine level, higher total oxidant status, and neuropathy in diabetic patients may explain the RLS symptoms.

Skeletal muscle signaling and the heart rate and blood pressure response to exercise

DEFF Research Database (Denmark)

Mortensen, Stefan P; Svendsen, Jesper H; Ersbøll, Mads

2013-01-01

Endurance training lowers heart rate and blood pressure responses to exercise, but the mechanisms and consequences remain unclear. To determine the role of skeletal muscle for the cardioventilatory response to exercise, 8 healthy young men were studied before and after 5 weeks of 1-legged knee-ex...... was ≈ 15 bpm lower during exercise with the trained leg (P...

Two Pilot Studies of the Effect of Bicycling on Balance and Leg Strength among Older Adults

OpenAIRE

Rissel, Chris; Passmore, Erin; Mason, Chloe; Merom, Dafna

2013-01-01

Objectives. Study 1 examines whether age-related declines in balance are moderated by bicycling. Study 2 tests whether regular cycling can increase leg strength and improve balance. Methods. Study 1: a cross-sectional survey of 43 adults aged 44–79 was conducted. Leg strength was measured, and Balance was measured using the choice stepping reaction time (CSRT) test (decision time and response time), leg strength and timed single leg standing. Study 2: 18 older adults aged 49–72 were recruited...

A study on the strength of leg extention and leg curl exercise measured with the "Tremax System" and the "ADR" (Aero Dynamic Resistance System)

OpenAIRE

安藤, 勝英

1995-01-01

This is a study on the nature of the extensor and flexor muscles by the leg extention and leg curl exercise. The strength of the static muscles were measured with the "Tremax system" and for the strength of the dynamic muscles the "ADR" was used. Measuring the strength of the extensor muscles at bar no.1 to 4 of the Tremax System，it comes to a maximum at bar no.2 (extention 60°) but it declines radically when approaching extention 0°. Compared to the extensor muscles, the flexor muscules show...

Clinical aspects of lower leg compartment syndrome

NARCIS (Netherlands)

Brand, Johan Gerard Henric van den

2004-01-01

A compartment syndrome is a condition in which increased pressure within a limited space compromises the circulation and function of tissues within that space. Although pathofysiology is roughly similar in chronic exertional and acute compartment syndrome of the lower leg, the clinical

Parallel kinematics robot with five legs

NARCIS (Netherlands)

Lambert, P.

2011-01-01

Robot with multiple degrees of freedom comprising five legs (2) linked at a first of their ends to a base ( 3), and at a second of their ends opposite to the first ends to a mobile platform (4), which platform carries at least one tool (5, 6, 121, 12 "), and wherein the robot further comprises an

THE EFFECTS OF DIFFERENT WORK-LOADING APPLIED TO THE WORKERS THAT WORK PRODUCING OF SHIRT TO THE SEAM FAULT RATES

Directory of Open Access Journals (Sweden)

Önder YÜCEL

2001-03-01

Full Text Available Human efficiency is of big importance in the clothing industry. So as to provide high quality and productivity stabilized work –loading must be given to the workers that work in the cloth production lines. In addition to it, the kind of work must be paid attention in the studies to be done on stabilized work-loading. The aim of this study is to determine the effects of different work-loading to the seam fault rates. For this purpose, four different work-loading had been applied to the workers and determined seam faults on the clothes had been recorded. As a result of this study, seam fault rates in the different work-loading had been evaluated.

Leg Lengthening as a Means of Improving Ambulation Following an Internal Hemipelvectomy

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Wakyo Sato

2016-01-01

Full Text Available Reconstructive surgery following an internal hemipelvectomy for a malignant pelvic tumor is difficult due to the structural complexity of the pelvis and the massive extension of the tumor. While high complication rates have been encountered in various types of reconstructive surgery, resection without reconstruction reportedly involved fewer complications. However, this method often results in limb shortening with resultant instability during walking. We reported herein leg lengthening performed to correct lower limb shortening after an internal hemipelvectomy, which improved ambulatory stability and overall QOL. An 18-year-old male patient came to our hospital to correct a lower limb discrepancy resulting from a left internal hemipelvectomy. His left pelvis and proximal femur had been resected, and the femur remained without an acetabular roof. His left lower limb was about 8 centimeters shorter. The left tibia was lengthened 8 centimeters with an external fixator. After the lengthening, the patient was able to walk without support and his gait remarkably improved. Additionally he no longer required placing a wallet in his back pocket as a pad as a means of raising the left side of his torso while sitting. Leg lengthening was a useful method of improving ambulation after an internal hemipelvectomy.

COMPARISON OF UNILATERAL SQUAT STRENGTH BETWEEN THE DOMINANT AND NON-DOMINANT LEG IN MEN AND WOMEN

Directory of Open Access Journals (Sweden)

Kevin McCurdy

2005-06-01

Full Text Available The purpose of this study was to compare unilateral squat strength of the dominant and non-dominant leg in young adult men and women. Seventeen apparently healthy men (mean mass 90.5 ± 20.9 kg and age 21.7 ± 1.8 yrs and 25 women (mean mass 62.2 ± 14.5 kg and age 21.9 ± 1.3 yrs completed the study. To determine unilateral strength, the subjects completed a one repetition maximum (1RM modified unilateral squat (MUS on the dominant and non-dominant leg. The subjects completed the squat to a depth that attained a 90º angle at the knee. This exercise was executed by placing the top of the metatarsophalangeal area of the foot of the uninvolved leg on a support bar behind the subject to isolate the use of the lead leg. Paired samples t-test revealed no significant difference between the men's 1RM mean strength on the dominant (107.0 ± 21.4 kg and non-dominant (106.0 ± 21.4 kg leg with a mean side-to-side difference (comparing the stronger to the weaker leg of 2.8 %. Leg strength symmetry was also found between the women's 1RM mean strength on the dominant (45.3 ± 12.5 kg and non-dominant (45.0 ± 12.4 kg leg with a mean side-to-side difference of 5.0 %. The data indicate that unilateral squat strength, measured in a weight bearing stance, is similar in the dominant and non-dominant leg in apparently healthy young adult men and women

The work-related fatal injury study: numbers, rates and trends of work-related fatal injuries in New Zealand 1985-1994.

Science.gov (United States)

Feyer, A M; Langley, J; Howard, M; Horsburgh, S; Wright, C; Alsop, J; Cryer, C

2001-01-26

To determine the number and rates of work-related fatal injuries by employment status, occupation, industry, age and gender in New Zealand 1985-1994. Potential cases of work-related injury deaths of persons aged 15-84 years were identified from the national electronic mortality data files. Main exclusions were deaths due to suicide and deaths due to motor vehicle crashes. The circumstances of the deaths of each fatal incident meeting inclusion criteria were then reviewed directly from coronial files to determine work-relatedness. The rate of work-related fatal injury in New Zealand was 5.03/100000 workers per year for the study period. There was a significant decline in crude rate over the study period. However, this was in substantial part accounted for by changes in occupation and industry mix. Older workers, male workers, self-employed workers, and particular occupational groups, all had substantially elevated rates. Agricultural and helicopter pilots, forestry workers and fishery workers had the highest rates. Farmers, forestry workers, and fishery workers also had high numbers of deaths, together accounting for nearly 40% of all deaths. This study has demonstrated that work-related fatal injury remains a pressing problem for New Zealand. Several areas in urgent need of prevention efforts were highlighted.

Association of Serum Uric Acid Levels with Leg Ischemia in Patients with Peripheral Arterial Disease after Treatment.

Science.gov (United States)

Sotoda, Yoko; Hirooka, Shigeki; Orita, Hiroyuki; Wakabayashi, Ichiro

2017-07-01

We investigated the relationships of serum uric acid levels with the progression of atherosclerosis in patients with peripheral arterial disease (PAD) after treatment. Subjects were male patients diagnosed with PAD. Atherosclerosis at the common carotid artery was evaluated based on its intima-media thickness (IMT). Leg arterial flow was evaluated by measuring ankle-brachial index (ABI) and exercise-induced decrease in ABI. Among various risk factors including age, blood pressure, adiposity, estimated glomerular filtration rate, and blood lipid, blood glucose, uric acid, fibrinogen and C-reactive protein levels, only uric acid levels showed significant correlations with ABI [Pearson's correlation coefficient, -0.292 (p＜0.01)] and leg exercise-induced decrease in ABI [Pearson's correlation coefficient, 0.236 (p＜ 0.05)]. However, there was no significant correlation between uric acid levels and maximum or mean IMT. Odds ratios of subjects with the 3rd tertile versus subjects with the 1st tertile for uric acid levels were significantly higher than the reference level of 1.00 for low ABI [4.44 (95% confidence interval, 1.45-13.65, p＜0.01)] and for high % decrease in ABI after exercise [4.31 (95% confidence interval, 1.34-13.82, p＜0.05)]. The associations of uric acid levels with the indicators of leg ischemia were also found after adjustment for age, history of revascularization therapy, diabetes, smoking, alcohol consumption, body mass index, triglyceride levels, and renal function. Uric acid levels are associated with the degree of leg ischemia in patients with PAD. Further interventional studies are needed to determine whether the correction of uric acid levels is effective in preventing the progression of PAD.

Data report for ROSA-IV LSTF 10% hot leg break experiment Run SB-HL-04

International Nuclear Information System (INIS)

Kukita, Yutaka; Nakamura, Hideo; Saeki, Hiroyuki

1991-03-01

Experimental data for the 10% hot leg break test, Run SB-HL-04, conducted on March 29, 1988 at the ROSA-IV Large Scale Test Facility (LSTF), are presented. This test was conducted as part of test series which studied the effect of break orientation on 10% hot leg break transient, and represented a vertical upward break. Other two tests in this test series represented horizontal break and vertical downward break, respectively. The results of these tests were characterized by asymmetric loop responses, flashing in the cold legs as well as upper downcomer, and condensation depressurization in the cold legs following injection of emergency core coolant (ECC) from accumulators. (author)

The relationship between leg preference and knee mechanics during sidestepping in collegiate female footballers.

Science.gov (United States)

Brown, Scott R; Wang, Henry; Dickin, D Clark; Weiss, Kaitlyn J

2014-11-01

This study examined the relationship between leg preference and knee mechanics in females during sidestepping. Three-dimensional data were recorded on 16 female collegiate footballers during a planned 45° sidestep manoeuvre with their preferred and non-preferred kicking leg. Knee kinematics and kinetics during initial contact, weight acceptance, peak push-off, and final push-off phases of sidestepping were analysed in both legs. The preferred leg showed trivial to small increases (ES = 0.19-0.36) in knee flexion angle at initial contact, weight acceptance, and peak push-off, and small increases (ES = 0.21-0.34) in peak power production and peak knee extension velocity. The non-preferred leg showed a trivial increase (ES = 0.10) in knee abduction angle during weight acceptance; small to moderate increases (ES = 0.22-0.64) in knee internal rotation angle at weight acceptance, peak push-off, and final push-off; a small increase (ES = 0.22) in knee abductor moment; and trivial increases (ES = 0.09-0.14) in peak power absorption and peak knee flexion velocity. The results of this study show that differences do exist between the preferred and non-preferred leg in females. The findings of this study will increase the knowledge base of anterior cruciate ligament injury in females and can aid in the design of more appropriate neuromuscular, plyometric, and strength training protocols for injury prevention.

Compression stockings for treating venous leg ulcers: measurement of interface pressure under a new ulcer kit.

Science.gov (United States)

Partsch, B; Partsch, H

2008-01-01

The aim of this study was to measure the interface pressure of a newly designed two-layer compression stocking (Mediven ulcer kit Medi QMBH, Bayreuth, Germany) in different body positions and to compare the values with those obtained with another two-layer product. Interface pressure was measured on the distal medial leg in 16 legs of volunteers, with the basic layer alone and with the whole stocking kit in the supine, sitting and standing position for both stocking systems. The literature concerning ulcer-healing rates is reviewed. Mediven ulcerkit produced statistically significant higher pressure values than the ulcer stocking with a median resting value of 35.5 mmHg in the supine and 42.5 mmHg in the standing position. The pressure while standing comes close to values exerted by bandages. The basic layer alone applies a pressure of 20.5 mmHg. Especially designed compression stockings exerting sufficient interface pressure may be indicated in patients with small ulcers of short duration.

Parametric study on the behavior of an innovative subsurface tension leg platform in ultra-deep water

Science.gov (United States)

Zhen, Xing-wei; Huang, Yi

2017-10-01

This study focuses on a new technology of Subsurface Tension Leg Platform (STLP), which utilizes the shallowwater rated well completion equipment and technology for the development of large oil and gas fields in ultra-deep water (UDW). Thus, the STLP concept offers attractive advantages over conventional field development concepts. STLP is basically a pre-installed Subsurface Sea-star Platform (SSP), which supports rigid risers and shallow-water rated well completion equipment. The paper details the results of the parametric study on the behavior of STLP at a water depth of 3000 m. At first, a general description of the STLP configuration and working principle is introduced. Then, the numerical models for the global analysis of the STLP in waves and current are presented. After that, extensive parametric studies are carried out with regarding to SSP/tethers system analysis, global dynamic analysis and riser interference analysis. Critical points are addressed on the mooring pattern and riser arrangement under the influence of ocean current, to ensure that the requirements on SSP stability and riser interference are well satisfied. Finally, conclusions and discussions are made. The results indicate that STLP is a competitive well and riser solution in up to 3000 m water depth for offshore petroleum production.

Improved Leg Tracking Considering Gait Phase and Spline-Based Interpolation during Turning Motion in Walk Tests

Directory of Open Access Journals (Sweden)

Ayanori Yorozu

2015-09-01

Full Text Available Falling is a common problem in the growing elderly population, and fall-risk assessment systems are needed for community-based fall prevention programs. In particular, the timed up and go test (TUG is the clinical test most often used to evaluate elderly individual ambulatory ability in many clinical institutions or local communities. This study presents an improved leg tracking method using a laser range sensor (LRS for a gait measurement system to evaluate the motor function in walk tests, such as the TUG. The system tracks both legs and measures the trajectory of both legs. However, both legs might be close to each other, and one leg might be hidden from the sensor. This is especially the case during the turning motion in the TUG, where the time that a leg is hidden from the LRS is longer than that during straight walking and the moving direction rapidly changes. These situations are likely to lead to false tracking and deteriorate the measurement accuracy of the leg positions. To solve these problems, a novel data association considering gait phase and a Catmull–Rom spline-based interpolation during the occlusion are proposed. From the experimental results with young people, we confirm   that the proposed methods can reduce the chances of false tracking. In addition, we verify the measurement accuracy of the leg trajectory compared to a three-dimensional motion analysis system (VICON.

The bacteriology of chronic venous leg ulcer examined by culture-independent molecular methods

DEFF Research Database (Denmark)

Thomsen, Trine R; Aasholm, Martin S; Rudkjøbing, Vibeke B

2010-01-01

The bacterial microbiota plays an important role in the prolonged healing of chronic venous leg ulcers. The present study compared the bacterial diversity within ulcer material from 14 skin graft operations of chronic venous leg ulcers using culture-based methods and molecular biological methods...

Neuro fuzzy control of the FES assisted freely swinging leg of paraplegic subjects

NARCIS (Netherlands)

van der Spek, J.H.; Velthuis, W.J.R.; Veltink, Petrus H.; de Vries, Theodorus J.A.

1996-01-01

The authors designed a neuro fuzzy control strategy for control of cyclical leg movements of paraplegic subjects. The cyclical leg movements were specified by three `swing phase objectives', characteristic of natural human gait. The neuro fuzzy controller is a combination of a fuzzy logic controller

An automatic hinge system for leg orthoses

NARCIS (Netherlands)

Rietman, J.S.; Goudsmit, J.; Meulemans, D.; Halbertsma, J.P.K.; Geertzen, J.H.B.

This paper describes a new, automatic hinge system for leg orthoses, which provides knee stability in stance, and allows knee-flexion during swing. Indications for the hinge system are a paresis or paralysis of the quadriceps muscles. Instrumented gait analysis was performed in three patients,