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Sample records for ofone leg stand

  1. Intra-observer and interobserver reliability ofOne Leg Stand Test as a measure of posturalbalance in low back pain patients

    DEFF Research Database (Denmark)

    Maribo, Thomas; Iversen, Elena; Andersen, Niels Trolle

    2009-01-01

    Objective: To determine the absolute and relative reliability of intra-observer and interobserver To determine the absolute and relative reliability of intra-observer and interobserver measurements of postural balance using the One Leg Stand Test in patients with low back pain. Patients and methods...... to stand for the maximum time, and no further analysis was done. Eyes closed: intra-observer reliability was tested in 21 patients; absolute reliability showed a standard error of the measurement (SEM) of 2.48 s and a minimal detectable change (MDC) of 6.88. The relative reliability was acceptable...... with an intra class correlation coefficient (ICC) of 0.86. Interobserver reliability was tested in 27 patients; absolute reliability showed a SEM of 1.42 s and a MDC of 3.95. The relative reliability was acceptable with an ICC of 0.91. Conclusions: The One Leg Stand Test can be used to test postural balance...

  2. 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...

  3. 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.

  4. Vibration transmission characteristics of the legs of freely standing honeybees

    DEFF Research Database (Denmark)

    Rohrseitz, Kristin; Kilpinen, Ole

    1997-01-01

    as the stimulator. This was also the case in freely standing honeybees, except around 400 Hz, where an average attenuation of approximately 6 dB was observed. In the fixed bee preparation, the vertical movements of the legs were also measured during horizontal stimulation. The vertical vibration amplitude...... of the legs was 15-20 dB lower than the horizontal stimulation amplitude. The electrophysiologically and behaviourally determined thresholds for vibration stimulation increased by approximately 10 dB, when the stimulus direction was changed from vertical to horizontal. These observations support the notion...

  5. 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

  6. Strategies for equilibrium maintenance during single leg standing on a wobble board

    DEFF Research Database (Denmark)

    Silva, Priscila de Brito; Oliveira, Anderson Souza; Mrachacz-Kersting, Natalie

    2016-01-01

    The aim of this study was to identify and compare movement strategies used to maintain balance while single leg standing on either a firm surface (FS) or on a wobble board (WB). In 17 healthy men, retroreflective markers were positioned on the xiphoid process and nondominant lateral malleolus...... requires movement beyond the ankle strategy as described for the FS task. WB standing likely demands different biomechanical and neuromuscular control strategies, which has immediate implications for the significance of WB tests in contrast to FS balance tests. Differences in control strategies will also...

  7. Steadiness of Spinal Regions during Single-Leg Standing in Older Adults with and without Chronic Low Back Pain.

    Directory of Open Access Journals (Sweden)

    Yi-Liang Kuo

    Full Text Available The aims of this study were to compare the steadiness index of spinal regions during single-leg standing in older adults with and without chronic low back pain (LBP and to correlate measurements of steadiness index with the performance of clinical balance tests. Thirteen community-dwelling older adults (aged 55 years or above with chronic LBP and 13 age- and gender-matched asymptomatic volunteers participated in this study. Data collection was conducted in a university research laboratory. Measurements were steadiness index of spinal regions (trunk, thoracic spine, lumbar spine, and pelvis during single-leg standing including relative holding time (RHT and relative standstill time (RST, and clinical balance tests (timed up and go test and 5-repetition sit to stand test. The LBP group had a statistically significantly smaller RHT than the control group, regardless of one leg stance on the painful or non-painful sides. The RSTs on the painful side leg in the LBP group were not statistically significantly different from the average RSTs of both legs in the control group; however, the RSTs on the non-painful side leg in the LBP group were statistically significantly smaller than those in the control group for the trunk, thoracic spine, and lumbar spine. No statistically significant intra-group differences were found in the RHTs and RSTs between the painful and non-painful side legs in the LBP group. Measurements of clinical balance tests also showed insignificant weak to moderate correlations with steadiness index. In conclusion, older adults with chronic LBP demonstrated decreased spinal steadiness not only in the symptomatic lumbar spine but also in the other spinal regions within the kinetic chain of the spine. When treating older adults with chronic LBP, clinicians may also need to examine their balance performance and spinal steadiness during balance challenging tests.

  8. So Why Would a Pigeon Stand on One Leg (or Limp without Hurting)?

    Science.gov (United States)

    Hrepic, Zdeslav

    2012-01-01

    While we still do not have a definitive answer about the reason(s) for which birds stand on one leg, a list of suggestions has been offered both by expert ornithologists and amateur birdwatchers. We offer a perspective grounded in statics and rotational dynamics that has not been suggested in the literature. The discussion has implications for…

  9. One- or Two-Legged Standing: What Is the More Suitable Protocol to Assess the Postural Effects of the Rigid Ankle Orthosis?

    Science.gov (United States)

    Rougier, Patrice; Genthon, Nicolas; Gallois-Montbrun, Thibault; Brugiere, Steve; Bouvat, Eric

    2009-01-01

    To highlight the capacity of one- and two-legged standing protocols when assessing postural behavior induced by a rigid ankle orthosis, 14 healthy individuals stood upright barefoot and wore either an elastic stocking on the preferred leg or a rigid orthosis with or without additional taping in one- or two-legged (TL) conditions. Traditional…

  10. 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.

  11. Short communication: experimentally induced mastitis reduces weight shifting between the rear legs while standing in dairy cows.

    Science.gov (United States)

    Chapinal, N; Fitzpatrick, C E; Leslie, K E; Wagner, S A

    2013-05-01

    The objectives of this study were to evaluate changes in weight shifting between legs while standing on a weighing platform in response to endotoxin-induced clinical mastitis, and to evaluate the effect of the nonsteroidal antiinflammatory drug flunixin meglumine on weight distribution between legs while standing in dairy cattle with endotoxin-induced clinical mastitis. Clinical mastitis was induced in 10 primiparous and 9 multiparous lactating dairy cows (days in milk=55 ± 12; mean ± standard deviation) by intramammary infusion of 100 µg of Escherichia coli lipopolysaccharide (LPS) into the right rear quarter. Four hours later, 10 animals were randomly assigned to receive flunixin meglumine intravenously (2.2mg/kg of body weight; treated group) and 9 received an equivalent volume of sterile isotonic saline solution (control group). Body temperature was monitored rectally 3d before LPS infusion, immediately before LPS infusion, and 4, 7, 10, 13, 16, and 28 h after LPS infusion. The weight applied to each leg was recorded while cows were standing on a weighing platform on the day before the challenge and 7, 10, 13, 16, and 28 h after LPS infusion. Two measures of weight shifting between the rear legs were calculated for each recording session: the standard deviation of the weight applied to the legs over time and the frequency of steps. The LPS infusion resulted in a consistent case of clinical mastitis approximately 4h after the LPS infusion, as assessed by the presence of visible swelling and elevated rectal temperature in all cows. However, control animals had a higher temperature 7h after LPS infusion compared with treated animals (40.8 vs. 39.0°C; standard error of the difference=0.2). Overall, weight shifting between the rear legs was decreased 7h after the LPS infusion compared with baseline, and this decrease was not affected by treatment with flunixin meglumine. It is likely that weight shifting increases friction between the swollen udder and the legs

  12. 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. ...

  13. Postural adjustments associated with voluntary contraction of leg muscles in standing man.

    Science.gov (United States)

    Nardone, A; Schieppati, M

    1988-01-01

    The postural adjustments associated with a voluntary contraction of the postural muscles themselves have been studied in the legs of normal standing men. We focussed on the following questions. Do postural adjustments precede the focal movement as in the case of movements of the upper limb? Which muscle(s) are involved in the task of stabilizing posture? Can the same postural muscle be activated in postural stabilization and in voluntary movement at the same time, in spite of the opposite changes in activity possibly required by these conditions? Six subjects standing on a dynamometric platform were asked to rise onto the tips their toes by contracting their soleus muscles, or to rock on their heels by contracting their tibialis anterior muscles. The tasks were made in a reaction time (RT) situation or in a self-paced mode, standing either freely or holding onto a stable structure. Surface EMGs of leg and thigh muscles, and the foot-floor reaction forces were recorded. The following results were obtained in the RT mode, standing freely. 1. Rising onto toe tips: a striking silent period in soleus preceded its voluntary activation; during this silent period, a tibialis anterior burst could be observed in three subjects; these anticipatory activities induced a forward sway, as monitored by a change in the force exerted along the x axis of the platform. 2. Rocking on heels: an enhancement in tonic EMG of soleus was observed before tibialis anterior voluntary burst, at a mean latency from the go-signal similar to that of the silent period; this anticipatory activity induced a backward body sway. 3. Choice RT conditions showed that the above anticipatory patterns in muscle activity were pre-programmed, specific for the intended tasks, and closely associated with the focal movement. When both tasks were performed in a self-paced mode, all the above EMG and mechanical features were more pronounced and unfolded in time. If the subjects held onto the frame, the early

  14. Lateral radiography of the knee with single-leg standing

    International Nuclear Information System (INIS)

    Ohmori, Kan; Sugawara, Tsuyoshi; Murakami, Katsuyoshi; Kirinai, Mikio; Fujiwara, Junichi; Oikawa, Takumi; Matsumura, Yutaka; Sugawara, Tsukasa

    2002-01-01

    The purpose of this investigation was to accomplish reproducible radiography of single-leg standing lateral radiography of the knee by adjusting lateral rotation using a ruler to measure foot position. After preliminary assessment of three-dimensional CT of the knees of normal volunteers, the best adjustment of external rotation was estimated. A ruler was made for use in adjusting the angle of knee rotation by measuring foot rotation. Based on the foot rotation measured by this ruler, the positioning of radiography was adjusted to correct rotation. Rotation was estimated by the distance between the posterior edges of the lateral and medial femoral condyles. Fifteen-degree and 17.5-degree rotations were used for correction. Correction of rotation was 17 degrees on average. This helped not only to correct external rotation in the initial radiography but also to correct rotation for repeat radiography. Our method is quantitative and highly reproducible, and it increases the success rate of lateral knee radiography. (author)

  15. Calculations of mechanisms for balance control during narrow and single-leg standing in fit older adults: A reliability study.

    Science.gov (United States)

    Aberg, A C; Thorstensson, A; Tarassova, O; Halvorsen, K

    2011-07-01

    For older people balance control in standing is critical for performance of activities of daily living without falling. The aims were to investigate reliability of quantification of the usage of the two balance mechanisms M(1) 'moving the centre of pressure' and M(2) 'segment acceleration' and also to compare calculation methods based on a combination of kinetic (K) and kinematic (Km) data, (K-Km), or Km data only concerning M(2). For this purpose nine physically fit persons aged 70-78 years were tested in narrow and single-leg standing. Data were collected by a 7-camera motion capture system and two force plates. Repeated measure ANOVA and Tukey's post hoc tests were used to detect differences between the standing tasks. Reliability was estimated by ICCs, standard error of measurement including its 95% CI, and minimal detectable change, whereas Pearson's correlation coefficient was used to investigate agreement between the two calculation methods. The results indicated that for the tasks investigated, M(1) and M(2) can be measured with acceptable inter- and intrasession reliability, and that both Km and K-Km based calculations may be useful for M(2), although Km data may give slightly lower values. The proportional M(1):M(2) usage was approximately 9:1, in both anterio-posterior (AP) and medio-lateral (ML) directions for narrow standing, and about 2:1 in the AP and of 1:2 in the ML direction in single-leg standing, respectively. In conclusion, the tested measurements and calculations appear to constitute a reliable way of quantifying one important aspect of balance capacity in fit older people. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. The minimum sit-to-stand height test: reliability, responsiveness and relationship to leg muscle strength.

    Science.gov (United States)

    Schurr, Karl; Sherrington, Catherine; Wallbank, Geraldine; Pamphlett, Patricia; Olivetti, Lynette

    2012-07-01

    To determine the reliability of the minimum sit-to-stand height test, its responsiveness and its relationship to leg muscle strength among rehabilitation unit inpatients and outpatients. Reliability study using two measurers and two test occasions. Secondary analysis of data from two clinical trials. Inpatient and outpatient rehabilitation services in three public hospitals. Eighteen hospital patients and five others participated in the reliability study. Seventy-two rehabilitation unit inpatients and 80 outpatients participated in the clinical trials. The minimum sit-to-stand height test was assessed using a standard procedure. For the reliability study, a second tester repeated the minimum sit-to-stand height test on the same day. In the inpatient clinical trial the measures were repeated two weeks later. In the outpatient trial the measures were repeated five weeks later. Knee extensor muscle strength was assessed in the clinical trials using a hand-held dynamometer. The reliability for the minimum sit-to-stand height test was excellent (intraclass correlation coefficient (ICC) 0.91, 95% confidence interval (CI) 0.81-0.96). The standard error of measurement was 34 mm. Responsiveness was moderate in the inpatient trial (effect size: 0.53) but small in the outpatient trial (effect size: 0.16). A small proportion (8-17%) of variability in minimum sit-to-stand height test was explained by knee extensor muscle strength. The minimum sit-to-stand height test has excellent reliability and moderate responsiveness in an inpatient rehabilitation setting. Responsiveness in an outpatient rehabilitation setting requires further investigation. Performance is influenced by factors other than knee extensor muscle strength.

  17. 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).

  18. 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...

  19. Steadiness of Spinal Regions during Single-Leg Standing in Older Adults with and without Chronic Low Back Pain

    OpenAIRE

    Kuo, Yi-Liang; Huang, Kuo-Yuan; Chiang, Pei-Tzu; Lee, Pei-Yun; Tsai, Yi-Ju

    2015-01-01

    The aims of this study were to compare the steadiness index of spinal regions during single-leg standing in older adults with and without chronic low back pain (LBP) and to correlate measurements of steadiness index with the performance of clinical balance tests. Thirteen community-dwelling older adults (aged 55 years or above) with chronic LBP and 13 age- and gender-matched asymptomatic volunteers participated in this study. Data collection was conducted in a university research laboratory. ...

  20. Number of test trials needed for performance stability and interrater reliability of the one leg stand test in patients with a major non-traumatic lower limb amputation

    DEFF Research Database (Denmark)

    Kristensen, Morten Tange; Nielsen, Anni Østergaard; Madsen Topp, Ulla

    2014-01-01

    Balance is beneficial for daily functioning of patients with a lower limb amputation and sometimes assessed by the one-leg stand test (OLST). The aims of the study were to examine (1) the number of trials needed to achieve performance stability, (2) the interrater reliability of the OLST in patie......Balance is beneficial for daily functioning of patients with a lower limb amputation and sometimes assessed by the one-leg stand test (OLST). The aims of the study were to examine (1) the number of trials needed to achieve performance stability, (2) the interrater reliability of the OLST...... in patients with a major non-traumatic lower limb amputation, and (3) to provide a test procedure....

  1. 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.

  2. Test-retest reliability and minimal detectable change scores for sit-to-stand-to-sit tests, the six-minute walk test, the one-leg heel-rise test, and handgrip strength in people undergoing hemodialysis.

    Science.gov (United States)

    Segura-Ortí, Eva; Martínez-Olmos, Francisco José

    2011-08-01

    Determining the relative and absolute reliability of outcomes of physical performance tests for people undergoing hemodialysis is necessary to discriminate between the true effects of exercise interventions and the inherent variability of this cohort. The aims of this study were to assess the relative reliability of sit-to-stand-to-sit tests (the STS-10, which measures the time [in seconds] required to complete 10 full stands from a sitting position, and the STS-60, which measures the number of repetitions achieved in 60 seconds), the Six-Minute Walk Test (6MWT), the one-leg heel-rise test, and the handgrip strength test and to calculate minimal detectable change (MDC) scores in people undergoing hemodialysis. This study was a prospective, nonexperimental investigation. Thirty-nine people undergoing hemodialysis at 2 clinics in Spain were contacted. Study participants performed the STS-10 (n=37), the STS-60 (n=37), and the 6MWT (n=36). At one of the settings, the participants also performed the one-leg heel-rise test (n=21) and the handgrip strength test (n=12) on both the right and the left sides. Participants attended 2 testing sessions 1 to 2 weeks apart. High intraclass correlation coefficients (≥.88) were found for all tests, suggesting good relative reliability. The MDC scores at 90% confidence intervals were as follows: 8.4 seconds for the STS-10, 4 repetitions for the STS-60, 66.3 m for the 6MWT, 3.4 kg for handgrip strength (force-generating capacity), 3.7 repetitions for the one-leg heel-rise test with the right leg, and 5.2 repetitions for the one-leg heel-rise test with the left leg. Limitations A limited sample of patients was used in this study. The STS-16, STS-60, 6MWT, one-leg heel rise test, and handgrip strength test are reliable outcome measures. The MDC scores at 90% confidence intervals for these tests will help to determine whether a change is due to error or to an intervention.

  3. A comparison of ballet dancers with different level of experience in performing single-leg stance on retiré position.

    Science.gov (United States)

    Lin, Chia-Wei; Lin, Cheng-Feng; Hsue, Bih-Jen; Su, Fong-Chin

    2014-04-01

    The purpose of the current study was to evaluate the postural stability of single-leg standing on the retiré position in ballet dancers having three different levels of skill. Nine superior experienced female ballet dancers, 9 experienced, and 12 novice dancers performed single-leg standing in the retiré position. The parameters of center of pressure (COP) in the anterior-posterior and medial-lateral directions and the maximum distance between COP and the center of mass (COM) were measured. The inclination angles of body segments (head, torso, and supporting leg) in the frontal plane were also calculated. The findings showed that the novice dancers had a trend of greater torso inclination angles than the experienced dancers but that the superior experienced dancers had greater maximum COM-COP distance in the anterior-posterior direction. Furthermore, both experienced and novice dancers had better balance when standing on the nondominant leg, whereas the superior experienced dancers had similar postural stability between legs. Based on the findings, ballet training should put equal focus on both legs and frontal plane control (medial-lateral direction) should be integrated to ballet training program.

  4. Development of prolonged standing strain index to quantify risk levels of standing jobs.

    Science.gov (United States)

    Halim, Isa; Omar, Abdul Rahman

    2012-01-01

    Many occupations in industry such as metal stamping workers, electronics parts assembly operators, automotive industry welders, and lathe operators require working in a standing posture for a long time. Prolonged standing can contribute to discomfort and muscle fatigue particularly in the back and legs. This study developed the prolonged standing strain index (PSSI) to quantify the risk levels caused by standing jobs, and proposed recommendations to minimize the risk levels. Risk factors associated with standing jobs, such as working posture, muscles activity, standing duration, holding time, whole-body vibration, and indoor air quality, were the basis for developing the PSSI. All risk factors were assigned multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness. multipliers, and the PSSI was the product of those multipliers. Recommendations for improvement are based on the PSSI; however, extensive studies are required to validate their effectiveness.

  5. Two Pilot Studies of the Effect of Bicycling on Balance and Leg Strength among Older Adults

    Directory of Open Access Journals (Sweden)

    Chris Rissel

    2013-01-01

    Full Text Available 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 into a 12-week cycling program. The same pre- and postmeasures as used in Study 1 were collected. Results. Study 1: participants who had cycled in the last month performed significantly better on measures of decision time and response time. Study 2: cycling at least one hour a week was associated with significant improvements in balance (decision time and response time and timed single leg standing. Conclusions. Cycling by healthy older adults appears promising for improving risk factors for falls.

  6. Two Pilot Studies of the Effect of Bicycling on Balance and Leg Strength among Older Adults

    Science.gov (United States)

    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 into a 12-week cycling program. The same pre- and postmeasures as used in Study 1 were collected. Results. Study 1: participants who had cycled in the last month performed significantly better on measures of decision time and response time. Study 2: cycling at least one hour a week was associated with significant improvements in balance (decision time and response time) and timed single leg standing. Conclusions. Cycling by healthy older adults appears promising for improving risk factors for falls. PMID:23690805

  7. The effect of different unstable footwear constructions on centre of pressure motion during standing.

    Science.gov (United States)

    Plom, W; Strike, S C; Taylor, M J D

    2014-06-01

    The aim of this study was to test the effect different unstable footwear constructions have on centre of pressure motion when standing. Sixteen young female volunteers were tested in five conditions, three unstable footwear (Reebok Easy-Tone, FitFlop and Skechers Shape-Ups), a standard shoe and barefoot in a randomised order. Double and single leg balance on a force plate was assessed via centre of pressure excursions and displacements in each condition. For double leg and single leg standing centre of pressure excursions in the anterior-posterior direction were significantly increased wearing Skechers Shape-Ups compared to barefoot and the standard shoe. For the Reebok Easy Tone during single leg standing excursions in the anterior-posterior direction were significantly greater compared to the barefoot condition. Cumulative displacement of the centre of pressure in medial-lateral direction increased significantly during single leg standing when wearing Skechers Shape-Ups compared to barefoot and standard shoe as well as for Reebok Easy Tone vs. barefoot. It would appear from these quiet standing results that the manner of the construction of instability shoes effects the CoP movement which is associated with induced instability. Greater CoP excursion occurred in the A-P direction while the cumulative displacements were greater in the M-L direction for those shoes with the rounded sole and soft foam and those with airpods. The shoe construction with altered density foam did not induce any change in the CoP movement, during quite standing, which tends to suggest that it is not effective at inducing balance. Not all instability shoes are effective in altering the overall instability of the wearer. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Relationship between foot sensation and standing balance in patients with multiple sclerosis.

    Science.gov (United States)

    Citaker, Seyit; Gunduz, Arzu Guclu; Guclu, Meral Bosnak; Nazliel, Bijen; Irkec, Ceyla; Kaya, Defne

    2011-06-01

    The aims of the present study were to investigate the relationship between the foot sensations and standing balance in patients with Multiple Sclerosis (MS) and find out the sensation, which best predicts balance. Twenty-seven patients with MS (Expanded Disability Status Scale 1-3.5) and 10 healthy volunteers were included. Threshold of light touch-pressure, duration of vibration, and distance of two-point discrimination of the foot sole were assessed. Duration of static one-leg standing balance was measured. Light touch-pressure, vibration, two-point discrimination sensations of the foot sole, and duration of one-leg standing balance were decreased in patients with MS compared with controls (pbalance in patients with MS. In the multiple regression analysis conducted in the 27 MS patients, 47.6% of the variance in the duration of one-leg standing balance was explained by two-point discrimination sensation of the heel (R(2)=0.359, p=0.001) and vibration sensation of the first metatarsal head (R(2)=0.118, p=0.029). As the cutaneous receptors sensitivity decreases in the foot sole the standing balance impairs in patients with MS. Two-point discrimination sensation of the heel and vibration sensation of the first metatarsal head region are the best predictors of the static standing balance in patients with MS. Other factors which could be possible to predict balance and effects of sensorial training of foot on balance should be investigated. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. 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...

  10. 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...

  11. LAB3 Cosmic Ray Test Stand Analysis of Steel Stack Supports

    International Nuclear Information System (INIS)

    Cease, H.

    1998-01-01

    A cosmic ray test stand is being constructed at Lab 3. The stand consists of two stacks of steel plates one resting on top of the other. The top stack is composed of 6 plates of steel making an overall stack size of 34.5-inch x 40-inch x 99-inch. The bottom stack also has 6 layers of plate making an overall size of approximately 49.5-inch x 82-inch x 99-inch. The bottom stack is supported with three support legs. See drawing 3823.000ME-900428 for the individual plate orientation. The minimum support leg size and necessary welds between plates are determined.

  12. The Comparing the Leg Muscles Electromyography during Single Leg Drop Landing in Pesplanus and Normal Men

    Directory of Open Access Journals (Sweden)

    mostafa bazvand

    2016-03-01

    Full Text Available Objective: pesplanus is one of the changes that brings about changes in muscle activation patterns. Being aware of muscles activity changes in various standing positions among pesplanus patients provides insights into preventing lower extremity injuries in this population. The aim of this study was to compare leg muscles electromyography during various standing positions in pesplanus and normal subjects. Methods: 60 healthy male university students, 30 subjects with pesplanus deformity (with average age 23/54±3/57 year, average height 175/34±7/62 cm, average weight 74/87±10/72 kg and 30 normal subjects (with average age 22/97±2/38 year, average height 176/6±5/59 cm, average weight 73/58±8/36 kg participated in this comparative study. Deformity of pesplanus was assessed with navicular drop test. Each subject performed single-leg landing dropping from 30cm height onto a force platform where muscles activity was recorded with EMG device. For data analysis, Matlab and Spss softwares were used and independent sample t-test was used to compare the dependent variables at a significance level of P &le 0/05. Results: Significant differences were observed between the two groups for the activities of the longus peroneus and anterior tibialis muscles ( p&le0/05 while no significant differences were observed in other muscles. Conclusion: The changes in the normal structure of the foot might affect muscle activities during standing, which can cause changes in the injury patterns. Therefore, it is proposed that focusing on corrective exercises and therapy plan can reduce these risks.

  13. AORN Ergonomic Tool 4: Solutions for Prolonged Standing in Perioperative Settings.

    Science.gov (United States)

    Hughes, Nancy L; Nelson, Audrey; Matz, Mary W; Lloyd, John

    2011-06-01

    Prolonged standing during surgical procedures poses a high risk of causing musculoskeletal disorders, including back, leg, and foot pain, which can be chronic or acute in nature. Ergonomic Tool 4: Solutions for Prolonged Standing in Perioperative Settings provides recommendations for relieving the strain of prolonged standing, including the use of antifatigue mats, supportive footwear, and sit/stand stools, that are based on well-accepted ergonomic safety concepts, current research, and access to new and emerging technology. Published by Elsevier Inc.

  14. Leg extension power asymmetry and mobility limitation in healthy older women

    NARCIS (Netherlands)

    Portegijs, Erja; Sipilä, Sarianna; Alen, Markku; Kaprio, Jaakko; Koskenvuo, Markku; Tiainen, Kristina; Rantanen, Taina

    2005-01-01

    OBJECTIVE: To investigate the association of asymmetry in leg extension power (LEP) with walking and standing balance. DESIGN: Cross-sectional analysis. SETTING: Research laboratory. PARTICIPANTS: Healthy female twins (N=419), ages 63 to 75 years. INTERVENTIONS: Not applicable. MAIN OUTCOME

  15. The development and evaluation of a program for leg-strengthening exercises and balance assessment using Kinect

    OpenAIRE

    Choi, Jin-Seung; Kang, Dong-Won; Seo, Jeong-Woo; Kim, Dae-Hyeok; Yang, Seung-Tae; Tack, Gye-Rae

    2016-01-01

    [Purpose] In this study, a program was developed for leg-strengthening exercises and balance assessment using Microsoft Kinect. [Subjects and Methods] The program consists of three leg-strengthening exercises (knee flexion, hip flexion, and hip extension) and the one-leg standing test (OLST). The program recognizes the correct exercise posture by comparison with the range of motion of the hip and knee joints and provides a number of correct action examples to improve training. The program mea...

  16. Does a 'tight' hamstring predict low back pain reporting during prolonged standing?

    Science.gov (United States)

    Raftry, Sean M; Marshall, Paul W M

    2012-06-01

    The purpose of this study was to investigate the relationship between hamstring passive stiffness and extensibility in asymptomatic individuals with the reporting of low back pain during 2-h prolonged standing. Twenty healthy participants with no history of low back pain (mean±SD, age 22.6±2.7 years, height 1.74±0.09 m, weight 76.2±14.8 kg). Low back pain (VAS score; mm) was continuously monitored during 2-h prolonged standing. Hamstring extensibility, passive stiffness, and stretch tolerance were measured before and after prolonged standing using an instrumented straight leg raise (iSLR). Ten participants reported a clinically relevant increase (Δ VAS>10mm) in low back pain during prolonged standing. Hamstring extensiblity (leg°(max)), passive stiffness (Nm.°(-1)), and stretch tolerance (VAS; mm) were no different between pain developers and non-pain developers. No changes in hamstring measures were observed following 2-h prolonged standing. No relationship was observed in this study between measures of hamstring extensibility and the reporting of low back pain during prolonged standing. There is no evidence to recommend hamstring extensibility interventions (i.e. passive stretching) as a means of reducing pain reporting in occupations requiring prolonged standing. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Relationship between lower extremity isometric muscle strength and standing balance in patients with multiple sclerosis.

    Science.gov (United States)

    Citaker, Seyit; Guclu-Gunduz, Arzu; Yazici, Gokhan; Bayraktar, Deniz; Nazliel, Bijen; Irkec, Ceyla

    2013-01-01

    Muscle strength and standing balance decrease in patients with Multiple Sclerosis (MS). The aim of the present study was to investigate the relationship between the lower extremity isometric muscle strength and standing balance in patients with MS. Forty-seven patients with MS and 10 healthy volunteers were included. Neurological disability level was assessed using Expanded Disability Status Scale (EDSS). Isometric strength of seven lower extremity muscles (hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor) was assessed using hand-held dynamometer. Duration of static one-leg standing balance was measured using digital chronometer. Hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor isometric muscle strength, and duration of one-leg standing balance were decreased in patients with MS when compared with controls (p isometric muscle strength and EDSS level was related duration of one-leg standing balance in patients with MS. All assessed lower extremity isometric muscle strength (except ankle dorsal flexor) was related with EDSS. Hip flexor-extensor-abductor-adductor, knee flexor-extensor, and ankle dorsal flexor isometric muscle strength decreases in ambulatory MS patients. Lower extremity muscle weakness and neurological disability level are related with imbalance in MS population. Hip and knee region muscles weakness increases the neurological disability level. For the better balance and decrease neurological disability level whole lower extremity muscle strengthening should be included in rehabilitation programs.

  18. Acute effects of rearfoot manipulation on dynamic standing balance in healthy individuals.

    Science.gov (United States)

    Wassinger, Craig A; Rockett, Ariel; Pitman, Lucas; Murphy, Matthew Matt; Peters, Charles

    2014-06-01

    Dynamic standing balance is essential to perform functional activities and is included in the treatment of many lower extremity injuries. Physiotherapists utilize many methods to restore standing balance including stability exercises, functional retraining, and manual therapy. The purpose of this study was to investigate the effects of a rearfoot distraction manipulation on dynamic standing balance. Twenty healthy participants (age: 24.4 ± 2.8 years; height: 162.9 ± 37.7 cm; mass: 68.0 ± 4.8 kg; right leg dominant = 20) completed this study. Following familiarization, dynamic standing balance was assessed during: (1) an experimental condition immediately following a rearfoot distraction manipulation, and (2) a control condition. Dominant leg balance was quantified using the Y-balance test which measures lower extremity reach distances. Reach distances were normalized to leg length and measured in the anterior, posteromedial and posterolateral directions. Overall balance was calculated through the summing of all normalized directions. Paired t-tests and Wilcoxon rank tests were used to compare balance scores for parametric and non-parametric data as appropriate. Significance was set at 0.05 a priori. Effect size (ES) was calculated to determine the clinical impact of the manipulation. Increased reach distances (indicating improved balance) were noted following manipulation for overall balance (p = 0.03, ES = 0.26) and in the posteromedial direction (p = 0.01, ES = 0.42). Reach distances did not differ for the anterior (p = 0.11, ES = 0.16) or posterolateral (p = 0.11, ES = 0.25) components. Dynamic standing balance improved after a rearfoot distraction manipulation in healthy participants. It is hypothesized that manual therapy applied to the foot and ankle may be beneficial to augment other therapeutic modalities when working with patients to improve dynamic standing balance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Radiosteriometric analysis of movement in the sacroiliac joint during a single-leg stance in patients with long-lasting pelvic girdle pain.

    Science.gov (United States)

    Kibsgård, Thomas J; Røise, Olav; Sturesson, Bengt; Röhrl, Stephan M; Stuge, Britt

    2014-04-01

    Chamberlain's projections (anterior-posterior X-ray of the pubic symphysis) have been used to diagnose sacroiliac joint mobility during the single-leg stance test. This study examined the movement in the sacroiliac joint during the single-leg stance test with precise radiostereometric analysis. Under general anesthesia, tantalum markers were inserted into the dorsal sacrum and the ilium of 11 patients with long-lasting and severe pelvic girdle pain. After two to three weeks, a radiostereometric analysis was conducted while the subjects performed a single-leg stance. Small movements were detected in the sacroiliac joint during the single-leg stance. In both the standing- and hanging-leg sacroiliac join, a total of 0.5 degree rotation was observed; however, no translations were detected. There were no differences in total movement between the standing- and hanging-leg sacroiliac joint. The movement in the sacroiliac joint during the single-leg stance is small and almost undetectable by the precise radiostereometric analysis. A complex movement pattern was seen during the test, with a combination of movements in the two joints. The interpretation of the results of this study is that, the Chamberlain examination likely is inadequate in the examination of sacroiliac joint movement in patients with pelvic girdle pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. 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.

  1. 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.

  2. Investigating the Impact of Dual Task Condition and Visual Manipulation on Healthy Young Old During Non-Dominant Leg Stance

    Directory of Open Access Journals (Sweden)

    Bahareh Zeynalzadeh Ghoochani

    2017-06-01

    Discussion: Standing on non-dominant leg is a challenging task that requires a well-balanced system to survive the primary decreased somatosensory input. Therefore, the examinee had to have the requisite capabilities to cope with the changes caused when extra manipulation was included. During the course of the study, the most challenging situation was encountered when the subjects were standing on their non-dominant leg with eyes shut, which should be exactingly checked not to create a risky point as an Achilles’ heel of balance system. It was observed that the non-dominant leg was more susceptible to be affected when an aging adult did not have access to the visual input or during performing dual tasks with eyes shut. It is thus recommended that such conditions should be included in balance assessment tests or interventions.

  3. 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.

  4. Malignant Transformation of Nodular Hidradenoma in the Lower Leg

    Directory of Open Access Journals (Sweden)

    Nhuan Ngo

    2018-05-01

    Full Text Available Nodular hidradenoma (NH is a benign adnexal tumor that arises from either eccrine or apocrine sweat glands. NH can originate from any cutaneous site, but the most common sites are the head and anterior surface of the trunk, with very rare cases in the extremities. Long-standing NH has been reported to undergo malignant transformation to malignant NH (MNH; however, its occurrence in the lower leg is extremely rare with only one other case reported to date. In this report, we present a rare case of MNH occurring in the lower leg which was resected with the intent to make a diagnosis. At the final follow-up after 11 months, no local recurrence or metastasis has been observed.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

    OpenAIRE

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

    2017-01-01

    Background 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...

  11. 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.

  12. 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.

  13. Validity of linear encoder measurement of sit-to-stand performance power in older people.

    Science.gov (United States)

    Lindemann, U; Farahmand, P; Klenk, J; Blatzonis, K; Becker, C

    2015-09-01

    To investigate construct validity of linear encoder measurement of sit-to-stand performance power in older people by showing associations with relevant functional performance and physiological parameters. Cross-sectional study. Movement laboratory of a geriatric rehabilitation clinic. Eighty-eight community-dwelling, cognitively unimpaired older women (mean age 78 years). Sit-to-stand performance power and leg power were assessed using a linear encoder and the Nottingham Power Rig, respectively. Gait speed was measured on an instrumented walkway. Maximum quadriceps and hand grip strength were assessed using dynamometers. Mid-thigh muscle cross-sectional area of both legs was measured using magnetic resonance imaging. Associations of sit-to-stand performance power with power assessed by the Nottingham Power Rig, maximum gait speed and muscle cross-sectional area were r=0.646, r=0.536 and r=0.514, respectively. A linear regression model explained 50% of the variance in sit-to-stand performance power including muscle cross-sectional area (p=0.001), maximum gait speed (p=0.002), and power assessed by the Nottingham Power Rig (p=0.006). Construct validity of linear encoder measurement of sit-to-stand power was shown at functional level and morphological level for older women. This measure could be used in routine clinical practice as well as in large-scale studies. DRKS00003622. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  14. The effect of three different foot interventions on standing balance in healthy adults

    DEFF Research Database (Denmark)

    Koblauch, Henrik; Samuelsen, Jona A. S.; Sporsheim, Susanne B.

    2018-01-01

    Study Design: Experimental, randomised crossover study.  Objectives: To investigate if three different interventions that provided plantar proprioceptive input were able to make acute improvements to the one-legged standing balance.  Background: Improved balance reduces the risk of falling. There...

  15. Standing economy: does the heterogeneity in the energy cost of posture maintenance reside in differential patterns of spontaneous weight-shifting?

    Science.gov (United States)

    Miles-Chan, Jennifer L; Fares, Elie-Jacques; Berkachy, Redina; Jacquet, Philippe; Isacco, Laurie; Schutz, Yves; Montani, Jean-Pierre; Dulloo, Abdul G

    2017-04-01

    Due to sedentarity-associated disease risks, there is much interest in methods to increase low-intensity physical activity. In this context, it is widely assumed that altering posture allocation can modify energy expenditure (EE) to impact body-weight regulation and health. However, we have recently shown the existence of two distinct phenotypes pertaining to the energy cost of standing-with most individuals having no sustained increase in EE during steady-state standing relative to sitting comfortably. Here, we investigated whether these distinct phenotypes are related to the presence/absence of spontaneous "weight-shifting", i.e. the redistribution of body-weight from one foot to the other. Using indirect calorimetry to measure EE in young adults during sitting and 10 min of steady-state standing, we examined: (i) heterogeneity in EE during standing (n = 36); (ii) EE and spontaneous weight-shifting patterns (n = 18); (iii) EE during spontaneous weight-shifting versus experimentally induced weight-shifting (n = 7), and; (iv) EE during spontaneous weight-shifting versus intermittent leg/body displacement (n = 6). Despite heterogeneity in EE response to steady-state standing, no differences were found in the amount or pattern of spontaneous weight-shifting between the two phenotypes. Whilst experimentally induced weight-shifting resulted in a mean EE increase of only 11% (range: 0-25%), intermittent leg/body displacement increased EE to >1.5 METs in all participants. Although the variability in spontaneous weight-shifting signatures between individuals does not appear to underlie heterogeneity in the energy cost of standing posture maintenance, these studies underscore the fact that leg/body displacement, rather than standing posture alone, is needed to increase EE above the currently defined sedentary threshold.

  16. Task driven optimal leg trajectories in insect-scale legged microrobots

    Science.gov (United States)

    Doshi, Neel; Goldberg, Benjamin; Jayaram, Kaushik; Wood, Robert

    Origami inspired layered manufacturing techniques and 3D-printing have enabled the development of highly articulated legged robots at the insect-scale, including the 1.43g Harvard Ambulatory MicroRobot (HAMR). Research on these platforms has expanded its focus from manufacturing aspects to include design optimization and control for application-driven tasks. Consequently, the choice of gait selection, body morphology, leg trajectory, foot design, etc. have become areas of active research. HAMR has two controlled degrees-of-freedom per leg, making it an ideal candidate for exploring leg trajectory. We will discuss our work towards optimizing HAMR's leg trajectories for two different tasks: climbing using electroadhesives and level ground running (5-10 BL/s). These tasks demonstrate the ability of single platform to adapt to vastly different locomotive scenarios: quasi-static climbing with controlled ground contact, and dynamic running with un-controlled ground contact. We will utilize trajectory optimization methods informed by existing models and experimental studies to determine leg trajectories for each task. We also plan to discuss how task specifications and choice of objective function have contributed to the shape of these optimal leg trajectories.

  17. The effect of a hybrid assistive limb® on sit-to-stand and standing patterns of stroke patients

    Science.gov (United States)

    Kasai, Rie; Takeda, Sunao

    2016-01-01

    [Purpose] The Hybrid Assistive Limb® (HAL®) robot suit is a powered exoskeleton that can assist a user’s lower limb movement. The purpose of this study was to assess the effectiveness of HAL® in stroke rehabilitation, focusing on the change of the sit-to-stand (STS) movement pattern and standing posture. [Subjects and Methods] Five stroke patients participated in this study. Single leg HAL® was attached to each subject’s paretic lower limb. The subjects performed STS three times both with and without HAL® use. A tri-axial accelerometer was used to assess the STS movement pattern. Forward-tilt angle (FTA) and the time required for STS were measured with and without HAL® use. Surface electromyography (EMG) of STS and standing were recorded to assess the vastus medialis muscle activities of the paretic limb. [Results] The average FTA without HAL® use was 35° and it improved to 43° with HAL® use. The time required for STS was longer for all subjects with HAL® use (without HAL® use: 3.42 s, with HAL® use: 5.11 s). The integrated EMGs of HAL® use compared to those without HAL®, were 83.6% and 66.3% for STS and standing, respectively. [Conclusion] HAL® may be effective in improving STS and standing patterns of stroke patients. PMID:27390416

  18. 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.

  19. Differences in Lower Extremity and Trunk Kinematics between Single Leg Squat and Step Down Tasks.

    Directory of Open Access Journals (Sweden)

    Cara L Lewis

    Full Text Available The single leg squat and single leg step down are two commonly used functional tasks to assess movement patterns. It is unknown how kinematics compare between these tasks. The purpose of this study was to identify kinematic differences in the lower extremity, pelvis and trunk between the single leg squat and the step down. Fourteen healthy individuals participated in this research and performed the functional tasks while kinematic data were collected for the trunk, pelvis, and lower extremities using a motion capture system. For the single leg squat task, the participant was instructed to squat as low as possible. For the step down task, the participant was instructed to stand on top of a box, slowly lower him/herself until the non-stance heel touched the ground, and return to standing. This was done from two different heights (16 cm and 24 cm. The kinematics were evaluated at peak knee flexion as well as at 60° of knee flexion. Pearson correlation coefficients (r between the angles at those two time points were also calculated to better understand the relationship between each task. The tasks resulted in kinematics differences at the knee, hip, pelvis, and trunk at both time points. The single leg squat was performed with less hip adduction (p ≤ 0.003, but more hip external rotation and knee abduction (p ≤ 0.030, than the step down tasks at 60° of knee flexion. These differences were maintained at peak knee flexion except hip external rotation was only significant in the 24 cm step down task (p ≤ 0.029. While there were multiple differences between the two step heights at peak knee flexion, the only difference at 60° of knee flexion was in trunk flexion (p < 0.001. Angles at the knee and hip had a moderate to excellent correlation (r = 0.51-0.98, but less consistently so at the pelvis and trunk (r = 0.21-0.96. The differences in movement patterns between the single leg squat and the step down should be considered when selecting a

  20. Combination of activity and lying/standing data for detection of oestrus in cows

    DEFF Research Database (Denmark)

    Jónsson, Ragnar Ingi; Blanke, Mogens; Poulsen, Niels Kjølstad

    2009-01-01

    is measured by a sensor attached to the hind leg of the cow. Activity and lying/standing behaviour are modelled as a discrete event system, constructed using automata theory. In an attempt to estimate a biologically relevant lying balance, a lying balance indicator is constructed and is influencing transition...

  1. The effect of medial arch support over the plantar pressure and triceps surae muscle strength after prolonged standing

    OpenAIRE

    Hindun Saadah; Deswaty Furqonita; Angela Tulaar

    2015-01-01

    Background: The activity with prolonged standing position is one of the causes of abnormalities in the lower leg and foot. The aim of this study is to discover the effect of medial arch support over the distribution of plantar pressure when standing and walking.Methods: This was an experimental study with pre- and post-design the strength of triceps surae muscle after prolonged standing, was also evaluated in an experimental study with pre- and post-design. Variables of plantar pressure measu...

  2. 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

  3. Role of the Frontal Cortex in Standing Postural Sway Tasks While Dual-Tasking: A Functional Near-Infrared Spectroscopy Study Examining Working Memory Capacity

    Directory of Open Access Journals (Sweden)

    Hiroyuki Fujita

    2016-01-01

    Full Text Available Posture control during a dual-task involves changing the distribution of attention resources between the cognitive and motor tasks and involves the frontal cortex working memory (WM. The present study aimed to better understand the impact of frontal lobe activity and WM capacity in postural control during a dual-task. High and low WM-span groups were compared using their reading span test scores. High and low WM capacity were compared based on cognitive and balance performance and hemoglobin oxygenation (oxyHb levels during standing during single (S-S, standing during dual (S-D, one leg standing during single (O-S, and one leg standing during dual (O-D tasks. For sway pass length, significant difference in only the O-D task was observed between both groups. oxyHb levels were markedly increased in the right dorsolateral prefrontal cortex and supplementary motor area in the high-span group during a dual-task. Therefore, WM capacity influenced the allocation of attentional resources and motor performance.

  4. 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…

  5. Association between leg strength and muscle cross-sectional area of the quadriceps femoris with the physical activity level in octogenarians.

    Science.gov (United States)

    Latorre-Román, Pedro Á; Arévalo-Arévalo, Juan Manuel; García-Pinillos, Felipe

    2016-06-03

    Aging is a complex physiological process whose main feature is the progressive loss of functionality, which may be delayed or attenuated by improving physical fitness.  To determine the association between leg strength and the muscle cross-sectional area of the quadriceps femoris in relation to physical activity level in the elderly.  Thirty-two functionally autonomous people over 80 years (men: 82.80±2.09 years; women: 83.77±4.09 years) participated in this study. The Barthel Index, the Yale Physical Activity Survey and the Chair Stand Test were the instruments used.  There were significant differences between sexes in muscle area (pmen. The muscle area and the Chair Stand Test correlated significantly with the walk index (r=0.445, pactivity index (r=0.430, pactivity index, muscle area and the Chair Stand Test, only the latter behaved as a predictor variable.  Muscle strength and muscle mass of quadriceps showed a significant association with the physical activity level in older people. Leg muscle strength was useful to reveal muscle mass and physical activity level in older people, which is relevant as a clinical practice indicator.

  6. Postural Control Characteristics during Single Leg Standing of Individuals with a History of Ankle Sprain: Measurements Obtained Using a Gravicorder and Head and Foot Accelerometry.

    Science.gov (United States)

    Abe, Yota; Sugaya, Tomoaki; Sakamoto, Masaaki

    2014-03-01

    [Purpose] This study aimed to validate the postural control characteristics of individuals with a history of ankle sprain during single leg standing by using a gravicorder and head and foot accelerometry. [Subjects] Twenty subjects with and 23 subjects without a history of ankle sprain (sprain and control groups, respectively) participated. [Methods] The anteroposterior, mediolateral, and total path lengths, as well as root mean square (RMS) of each length, were calculated using the gravicorder. The anteroposterior, mediolateral, and resultant acceleration of the head and foot were measured using accelerometers and were evaluated as the ratio of the acceleration of the head to the foot. [Results] There was no significant difference between the two groups in path length or RMS acceleration of the head and foot. However, the ratios of the mediolateral and resultant components were significantly higher in the sprain group than in the control group. [Conclusion] Our findings suggest that individuals with a history of ankle sprain have a higher head-to-foot acceleration ratio and different postural control characteristics than those of control subjects.

  7. Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

    Science.gov (United States)

    Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

    2016-09-01

    Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002adults for the trunk (0.001older adults for the ankle (0.009Older adults had higher electrophysiological costs for all stance conditions. Muscle coordination showed inverse activity patterns at the ankle and trunk. Optimal balance and strength training programs should take into account age-specific alterations in muscle activity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Single-leg squats can predict leg alignment in dancers performing ballet movements in "turnout".

    Science.gov (United States)

    Hopper, Luke S; Sato, Nahoko; Weidemann, Andries L

    2016-01-01

    The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve "turning out" or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in "turned out" postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat.

  9. Maintenance of Segmental Lordosis and Disk Height in Stand-alone and Instrumented Extreme Lateral Interbody Fusion (XLIF).

    Science.gov (United States)

    Malham, Gregory M; Ellis, Ngaire J; Parker, Rhiannon M; Blecher, Carl M; White, Rohan; Goss, Ben; Seex, Kevin A

    2017-03-01

    A prospective single-surgeon nonrandomized clinical study. To evaluate the radiographic and clinical outcomes, by fixation type, in extreme lateral interbody fusion (XLIF) patients and provide an algorithm for determining patients suitable for stand-alone XLIF. XLIF may be supplemented with pedicle screw fixation, however, since stabilizing structures remain intact, it is suggested that stand-alone XLIF can be used for certain indications. This eliminates the associated morbidity, though subsidence rates may be elevated, potentially minimizing the clinical benefits. A fixation algorithm was developed after evaluation of patient outcomes from the surgeon's first 30 cases. This algorithm was used prospectively for 40 subsequent patients to determine the requirement for supplemental fixation. Preoperative, postoperative, and 12-month follow-up computed tomography scans were measured for segmental and global lumbar lordosis and posterior disk height. Clinical outcome measures included back and leg pain (visual analogue scale), Oswestry Disability Index (ODI), and SF-36 physical and mental component scores (PCS and MCS). Preoperatively to 12-month follow-up there were increases in segmental lordosis (7.9-9.4 degrees, P=0.0497), lumbar lordosis (48.8-55.2 degrees, P=0.0328), and disk height (3.7-5.5 mm, P=0.0018); there were also improvements in back (58.6%) and leg pain (60.0%), ODI (44.4%), PCS (56.7%), and MCS (16.1%) for stand-alone XLIF. For instrumented XLIF, segmental lordosis (7.6-10.5 degrees, P=0.0120) and disk height (3.5-5.6 mm, Plordosis decreased (51.1-45.8 degrees, P=0.2560). Back (49.8%) and leg pain (30.8%), ODI (32.3%), PCS (37.4%), and MCS (2.0%) were all improved. Subsidence occurred in 3 (7.5%) stand-alone patients. The XLIF treatment fixation algorithm provided a clinical pathway to select suitable patients for stand-alone XLIF. These patients achieved positive clinical outcomes, satisfactory fusion rates, with sustained correction of lordosis and

  10. 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 ...

  11. Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

    Science.gov (United States)

    Hopper, Luke S; Sato, Nahoko; Weidemann, Andries L

    2016-01-01

    The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. PMID:27895518

  12. 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...

  13. 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.

  14. The effect of neoprene shorts on leg proprioception in Australian football players.

    Science.gov (United States)

    Cameron, Matthew L; Adams, Roger D; Maher, Chris G

    2008-06-01

    Our purpose was to assess the effect of wearing close-fitting neoprene shorts on swinging leg movement discrimination (MD) scores in elite level Australian Football players. Twenty players had their swinging leg MD assessed using the active movement extent discrimination apparatus (AMEDA), once wearing close-fitting neoprene and once wearing loose-fitting running shorts. Subjects were randomly allocated to one of the shorts conditions prior to repeating the test in the other condition. The AMEDA was used to assess the accuracy at which subjects judge the extent of a standing backward swinging leg movement corresponding to the late swing early stance phase of running. Each subject performed 40 movements made to one of five randomly set physical limits, and without the aid of vision made a judgment as to the perceived limit position. From the accuracy of these judgments, a movement discrimination (MD) score was calculated for each subject under each condition. Subjects were grouped as having low or high neuromuscular control, or ability to use proprioception when controlling active movements without vision, based on their loose-shorts MD score. Analysis was performed on the MD scores obtained for each limb from subjects in the two groups, under the two shorts-wearing conditions. There was no main effect of wearing close-fitting shorts when the cohort was treated as a whole. A significant interaction effect was obtained (F=17.027, p=0.0006) whereby the mean MD score of the low neuromuscular control ability group was improved when wearing neoprene shorts but was reduced for the high ability group. Wearing close-fitting neoprene shorts has a beneficial effect on leg swing judgment accuracy in subjects with low neuromuscular control ability. Conversely, leg swing judgment accuracy for subjects with high ability was reduced by wearing neoprene shorts.

  15. 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

  16. 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....

  17. Assessment of the underlying systems involved in standing balance: the additional value of electromyography in system identification and parameter estimation

    NARCIS (Netherlands)

    Pasma, J.H.; Kordelaar, J. van; Kam, D. de; Weerdesteyn, V.G.M.; Schouten, A.C.; Kooij, H. van der

    2017-01-01

    BACKGROUND: Closed loop system identification (CLSIT) is a method to disentangle the contribution of underlying systems in standing balance. We investigated whether taking into account lower leg muscle activation in CLSIT could improve the reliability and accuracy of estimated parameters identifying

  18. Assessment of the underlying systems involved in standing balance : the additional value of electromyography in system identification and parameter estimation

    NARCIS (Netherlands)

    Pasma, J. H.; Van Kordelaar, J.; de Kam, D.; Weerdesteyn, V.; Schouten, A. C.; Van Der Kooij, H.

    2017-01-01

    Background: Closed loop system identification (CLSIT) is a method to disentangle the contribution of underlying systems in standing balance. We investigated whether taking into account lower leg muscle activation in CLSIT could improve the reliability and accuracy of estimated parameters identifying

  19. Assessment of the underlying systems involved in standing balance : The additional value of electromyography in system identification and parameter estimation

    NARCIS (Netherlands)

    Pasma, J.H.; van Kordelaar, J.; de Kam, D.; Weerdesteyn, V.; Schouten, A.C.; van der Kooij, H.

    2017-01-01

    Background: Closed loop system identification (CLSIT) is a method to disentangle the contribution of underlying systems in standing balance. We investigated whether taking into account lower leg muscle activation in CLSIT could improve the reliability and accuracy of estimated parameters

  20. 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.

  1. Single-leg squats can predict leg alignment in dancers performing ballet movements in “turnout”

    Directory of Open Access Journals (Sweden)

    Hopper LS

    2016-11-01

    Full Text Available Luke S Hopper,1 Nahoko Sato,2 Andries L Weidemann1 1Western Australian Academy of Performing Arts, Edith Cowan University, Mt Lawley, WA, Australia; 2Department of Physical Therapy, Nagoya Gakuin University, Seto, Japan Abstract: The physical assessments used in dance injury surveillance programs are often adapted from the sports and exercise domain. Bespoke physical assessments may be required for dance, particularly when ballet movements involve “turning out” or external rotation of the legs beyond that typically used in sports. This study evaluated the ability of the traditional single-leg squat to predict the leg alignment of dancers performing ballet movements with turnout. Three-dimensional kinematic data of dancers performing the single-leg squat and five ballet movements were recorded and analyzed. Reduction of the three-dimensional data into a one-dimensional variable incorporating the ankle, knee, and hip joint center positions provided the strongest predictive model between the single-leg squat and the ballet movements. The single-leg squat can predict leg alignment in dancers performing ballet movements, even in “turned out” postures. Clinicians should pay careful attention to observational positioning and rating criteria when assessing dancers performing the single-leg squat. Keywords: injury, motion capture, clinical assessment

  2. DIFFERENCES IN EXPLOSIVE STRENGTH OF LEGS OF FOOTBALLERS OF CADET CATEGORIES

    Directory of Open Access Journals (Sweden)

    Nebojša Nedeljkov

    2011-09-01

    Full Text Available In structure football is very complicated and complex activity. Today's level of development of football game requires of players a high level and rhythm of the game, excellent physical condition, high technical standards in motion that depend on many motor skills. Various beginnings of movement, acceleration, stopping at high speed, changing direction, jumping, ball hitting are the most common movings in which explosive power of players is exhibited. Observing the activities of the game, players need most, the form of power, which is reflected in the shortest possible interval, ie. explosive strength. The study aims to determine the difference in explosive strength of legs of footballers of cadet category. The sample consisted of 60 players, divided into two groups of 30 subjects, aged 15 ± 1 years. One group was composed of Serbian national team and the other football players of FC ‘Vojvodina’ from Novi Sad. Sample tests consisted of six tests, as follows: running speed of 10 meters from a standing start, running speed 20 meters from a standing start, running speed 30 meters from a standing start, a jump up from the spot, standing long jump and triple jump. To examine whether statistically significant differences between groups of players we used t-test for two independent groups. Generally it can be concluded that there was a statistically significant difference between the two treatment groups of respondents in favor of the representatives of Serbi

  3. 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.

  4. OSTEOPATHIC APPROACH: LEG LENGTH DISCREPANCY AND LOW BACK PAIN

    Directory of Open Access Journals (Sweden)

    Taner AYDIN

    2015-12-01

    Full Text Available Leg length discrepancy (LLD is a biomechanical impediment, which is a potential factor in affecting musculoskeletal disorders in the rest of life, such as scoliosis, osteoarthritis and muscle tightness, or even tenderness in lumbar and pelvic area. Athletes who have developed LLD have symptoms in gait, running, standing posture. Skeletal regions related to the disorder are the lumbar spine, ilium, hip joint, greater trochanter and knee, or even ankle and plantar region. Muscles involved in these areas are numeous. In osteopathic management, the manual practitioner can use a lot of basic techniques to handle these dysfunctions. To cope with musculoskeletal problems, osteopathic manipulation techniques would be an ideal modality to alleviate the LLD syndrome. An overview of the mentioned topics of concern will be discussed in the review.

  5. Analysis of ATLAS Cold Leg SBLOCA Using SPACE Code

    International Nuclear Information System (INIS)

    Kang, Doo Hyuk; Suh, Jae Seung; Kim, Se Yun

    2012-01-01

    SPACE Code has been developed to predict the thermal-hydraulic responses of nuclear steam supply system to the anticipated transients and postulated accidents and adopted advanced physical modeling of two-phase flows, mainly two-fluid, three-field models that comprise gas, continuous liquid, and droplet fields and has the capability to simulate 3D effects by the use of structured and/or non-structured meshes. In this paper, a cold-leg SBLOCA which is the experiment, SB-CL-09, of the ATLAS integral effect test facility during the second domestic stand problem (DSP-02) was analyzed. The results were compared with those of MARS-KS code simulations. The SPACE code with a 1.0 version was released by KHNP in 2012. The analysis has been performed in a desktop PC with Windows 7 environment

  6. Numerical Estimation of Balanced and Falling States for Constrained Legged Systems

    Science.gov (United States)

    Mummolo, Carlotta; Mangialardi, Luigi; Kim, Joo H.

    2017-08-01

    Instability and risk of fall during standing and walking are common challenges for biped robots. While existing criteria from state-space dynamical systems approach or ground reference points are useful in some applications, complete system models and constraints have not been taken into account for prediction and indication of fall for general legged robots. In this study, a general numerical framework that estimates the balanced and falling states of legged systems is introduced. The overall approach is based on the integration of joint-space and Cartesian-space dynamics of a legged system model. The full-body constrained joint-space dynamics includes the contact forces and moments term due to current foot (or feet) support and another term due to altered contact configuration. According to the refined notions of balanced, falling, and fallen, the system parameters, physical constraints, and initial/final/boundary conditions for balancing are incorporated into constrained nonlinear optimization problems to solve for the velocity extrema (representing the maximum perturbation allowed to maintain balance without changing contacts) in the Cartesian space at each center-of-mass (COM) position within its workspace. The iterative algorithm constructs the stability boundary as a COM state-space partition between balanced and falling states. Inclusion in the resulting six-dimensional manifold is a necessary condition for a state of the given system to be balanced under the given contact configuration, while exclusion is a sufficient condition for falling. The framework is used to analyze the balance stability of example systems with various degrees of complexities. The manifold for a 1-degree-of-freedom (DOF) legged system is consistent with the experimental and simulation results in the existing studies for specific controller designs. The results for a 2-DOF system demonstrate the dependency of the COM state-space partition upon joint-space configuration (elbow-up vs

  7. 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

  8. 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...

  9. 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

  10. 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...

  11. BIOMECHANICAL INDICES OF STANDING AND GAIT IN PATIENTS AFTER TOTAL KNEE REPLACEMENT USING COMPUTER NAVIGATION

    Directory of Open Access Journals (Sweden)

    Y. A. Bezgodkov

    2011-01-01

    Full Text Available Several biomechanical parameters of standing and walking in 50 patients with osteoarthrosis after total knee arthroplasty were evaluated. The patients were randomly divided in two equal groups: in the first group the surgery was performed with computer navigation system and in the second - with traditional instruments. After TKA with computer navigation centers of common body pressure and legs pressure during standing phase improved significantly better than in traditional group. Walking parameters like step length, ground contact time and rhythm coefficient improved in both groups of patients but without significant difference. Thereby more precise orientation of implant that achieved during computer assisted TKA leads to better functional performance at 6 and 12 month after surgery.

  12. 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

  13. 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.

  14. Design and Use of a 3D Prosthetic Leg in a Red-lored Amazon Parrot ( Amazona autumnalis).

    Science.gov (United States)

    Galicia, Cecilia; Hernandez Urraca, Vanessa; Del Castillo, Luis; Mvz, Jaime Samour

    2018-06-01

    A three-dimensional (3D) prosthesis was designed and built for a red-lored Amazon parrot ( Amazona autumnalis) with a pre-existing amputation of the distal left leg at the tibiotarsal-tarsometatarsal joint and injuries to the right leg caused by cage companion aggression. The prosthesis consisted of a straight main imprint, with a round element at both ends to provide stability, and a bridge connecting this to a socket without a bottom where the stump could be accommodated and held securely with self-adhesive bandaging. Over a 4-month period, 3 different 3D prosthetic models were made and evaluated. The first model was fitted, but the parrot would only use the tip of the main imprint to stand and walk. The second model was designed with a semicircular imprint with only 1 round element at the cranial end, a different bridge to accommodate the change to the main imprint, and the same socket. With these changes, the parrot was able to place the imprint of the prosthesis on the floor to stand and move freely around its enclosure. To accommodate morphologic changes on the stump, a third model was created consisting of the same imprint and bridge, but the socket was cut vertically all the way on one side to allow distention on its diameter and provide a long-lasting fit to the stump over time.

  15. The risk of varicose veins in standing female workers

    Directory of Open Access Journals (Sweden)

    Tony Hidayat

    2013-07-01

    Full Text Available AbstrakLatar belakang:Varises sering terjadi pada karyawan yang harus bekerja dalam posisi kerja berdiri. Tujuan penelitian ini untuk mengetahui beberapa faktor risiko terhadap varises tungkai dan atau kaki di antara pekerja perempuan. Metode:Penelitian potong lintang ini dilakukan pada Januari-Maret 2010. Sampel penelitian yang dipilih secara purposif yang memenuhi kriteria inklusi penelitian di antara pekerja perempuan perlu bekerja dalam  posisi  kerja  berdiri.  Data  dikumpulkan  dengan  wawancara,  pemeriksaan  fisik  dan  observasi posisi kerja berdiri. Pengolahan data untuk menentukan faktor dominan terhadap varises menggunakan pendekatan risiko relatif.Hasil:Dari 152 karyawan yang terdapat 111 yang bersedia mengikuti penelitian, dan yang menderita varises tungkai dan atau kaki sebanyak 52,3% (53 orang. Sebagian besar responden berusia 18-35 tahun, memiliki masa kerja 3-17 tahun, bekerja dalam posisi kerja banyak berdiri. Sebagian kecil responden memiliki riwayat varises di dalam keluarga (13,51%, memakai kontrasepsi oral (11,71%, memiliki kebiasaan olah raga (18,02% dan memakai sepatu hak tinggi (11,71%. Faktor umur, pemakaian kontrasepsi oral, pemakaian sepatu hak tinggi, kebiasaan olah raga, posisi kerja berdiri, tempat kerja, dan masa kerja tidak berhubungan dengan varises tungkai dan atau kaki. Karyawan yang mempunyai dibandingkan dengan yang tidak mempunyai riwayat keluarga varises, berisiko 69% lebih tinggi menderita varises [risiko relatif (RR = 1,69; P = 0.121]. Kesimpulan:Karyawan yang mempunyai riwayat keluarga varises berisiko lebih tinggi menderita varises. (Health Science Indones 2013;1:47-50 Kata kunci:varises, posisi kerja berdiriAbstractBackground: Varicose veins often occur in employees who have to work in a position of standing work. The purpose of this study to determine risk factors for varicose veins and leg or foot among women workers.Methods: In this cross-sectional study in January-March 2010 the

  16. 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...

  17. Not all is lost: old adults retain flexibility in motor behaviour during sit-to-stand.

    Directory of Open Access Journals (Sweden)

    Christian Greve

    Full Text Available Sit-to-stand is a fundamental activity of daily living, which becomes increasingly difficult with advancing age. Due to severe loss of leg strength old adults are required to change the way they rise from a chair and maintain stability. Here we examine whether old compared to young adults differently prioritize task-important performance variables and whether there are age-related differences in the use of available motor flexibility. We applied the uncontrolled manifold analysis to decompose trial-to-trial variability in joint kinematics into variability that stabilizes and destabilizes task-important performance variables. Comparing the amount of variability stabilizing and destabilizing task-important variables enabled us to identify the variable of primary importance for the task. We measured maximal isometric voluntary force of three muscle groups in the right leg. Independent of age and muscle strength, old and young adults similarly prioritized stability of the ground reaction force vector during sit-to-stand. Old compared to young adults employed greater motor flexibility, stabilizing ground reaction forces during sit-to-sand. We concluded that freeing those degrees of freedom that stabilize task-important variables is a strategy used by the aging neuromuscular system to compensate for strength deficits.

  18. 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...

  19. The causes of skin damage and leg ulceration in chronic venous disease.

    Science.gov (United States)

    Smith, Philip Coleridge

    2006-09-01

    Chronic venous disease with skin changes of the leg is a common condition affecting up to 1 in 20 people in westernized countries. The causes of this problem are not fully understood, although research in recent years has revealed a number of important mechanisms that contribute to the disease process. Patients with chronic venous disease suffer persistently raised pressures in their deep and superficial veins in the lower limb. Leucocytes become "trapped" in the circulation of the leg during periods of venous hyper-tension produced by sitting or standing. Studies of the plasma levels of neutrophil granule enzymes shows that these are increased during periods of venous hypertension, suggesting that this causes activation of the neutrophils. Investigation of the leucocyte surface ligands CD11b and CD62L shows that the more activated neutrophils and monocytes are sequestered during venous hypertension. Measurement of plasma levels of the soluble parts of the endothelial adhesion molecules VCAM, ICAM, and ELAM show that these are all elevated in patients with chronic venous disease compared to controls. Following 30 minutes of venous hypertension produced by standing, these levels are further increased. These data suggest that venous hypertension causes neutrophil and monocyte activation, which in turn causes injury to the endothelium. Chronic injury to the endothelium leads to a chronic inflammatory condition of the skin that we know clinically as lipodermatosclerosis. This is mediated by perivascular inflammatory cells, principally macrophages, in the skin microcirculation. These stimulate fibroblasts in the skin leading to tissue remodeling and laying down of fibrous tissue. Vascular endothelial growth factor stimulates proliferation of capillaries within the skin. Skin in this state has the potential to ulcerate in response to minor injury.

  20. 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.

  1. Influence of the Perspectives on the Movement of One-Leg Lifting in an Interactive-Visual Virtual Environment: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Chien-Hua Huang

    Full Text Available Numerous studies have confirmed the feasibility of active video games for clinical rehabilitation. To maximize training effectiveness, a personal program is necessary; however, little evidence is available to guide individualized game design for rehabilitation. This study assessed the perspectives and kinematic and temporal parameters of a participant's postural control in an interactive-visual virtual environment.Twenty-four healthy participants performed one-leg standing by leg lifting when a posture frame appeared either in a first- or third-person perspective of a virtual environment. A foot force plate was used to detect the displacement of the center of pressure. A three-way mixed factor design was applied, where the perspective was the between-participant factor, and the leg-lifting times (0.7 and 2.7 seconds and leg-lifting angles (30°and 90° were the within-participant factors. The reaction time, accuracy of the movement, and ability to shift weight were the dependent variables.Regarding the reaction time and accuracy of the movement, there were no significant main effects of the perspective, leg-lifting time, or angle. For the ability to shift weight, however, both the perspective and time exerted significant main effects, F(1,22 = 6.429 and F(1,22 = 13.978, respectively.Participants could shift their weight more effectively in the third-person perspective of the virtual environment. The results can serve as a reference for future designs of interactive-visual virtual environment as applied to rehabilitation.

  2. Influence of fear of falling on anticipatory postural control of medio-lateral stability during rapid leg flexion.

    Science.gov (United States)

    Yiou, E; Deroche, T; Do, M C; Woodman, T

    2011-04-01

    During leg flexion from erect posture, postural stability is organized in advance during "anticipatory postural adjustments" (APA). During these APA, inertial forces are generated that propel the centre of gravity (CoG) laterally towards stance leg side. This study examined how fear of falling (FoF) may influence this anticipatory postural control of medio-lateral (ML) stability. Ten young healthy participants performed a series of leg flexions at maximal velocity from low and high surface heights (6 and 66 cm above ground, respectively). In this latter condition with increased FoF, stance foot was placed at the lateral edge of the support surface to induce maximal postural threat. Results showed that the amplitude of ML inertial forces generated during APA decreased with FoF; this decrease was compensated by an increase in APA duration so that the CoG position at time of swing foot-off was located further towards stance leg side. With these changes in ML APA, the CoG was propelled in the same final (unipodal) position above stance foot as in condition with low FoF. These results contrast with those obtained in the literature during quiet standing which showed that FoF did not have any influence on the ML component of postural control. It is proposed that ML APA are modified with increased FoF, in such a way that the risk of a sideway fall induced by the large CoG motion is attenuated.

  3. Secure Microprocessor-Controlled Prosthetic Leg for Elderly Amputees: Preliminary Results

    Directory of Open Access Journals (Sweden)

    S. Krut

    2011-01-01

    Full Text Available We introduce a new prosthetic leg design, adapted to elderly trans-femoral amputees. Technical progress in prosthesis design mainly concerns active individuals. An important number of elderly amputees are not very mobile, tire easily, present reduced muscle strength, and have difficulties managing their balance. Therefore, the needs and characteristics of this specific population are very different from those of younger ones and the prosthetic solutions are not adapted. Our artificial knee has been designed to fulfill the specific requirements of this population in terms of capabilities, transfer assistance, security, intuitiveness, simplicity of use, and types of physical activity to be performed. We particularly focused our efforts on ensuring safe and secure stand-to-sit transfers. We developed an approach to control the different states of the prosthetic joint (blocked, free, resistant, associated with different physical activities. Amputee posture and motion are observed through a single multi-axis force sensor embedded in the prosthesis. The patient behaves naturally, while the controller analyses his movements in order to detect his intention to sit down. The detection algorithm is based on a reference pattern, calibrated individually, to which the sensor data are compared, and submitted to a set of tests allowing the discrimination of the intention to sit down from other activities. Preliminary validation of the system has been performed in order to verify the applicability of the prosthesis to different tasks: walking, standing, sitting down, standing up, picking up an object from a chair, slope and stair climbing.

  4. Quantifying walking and standing behaviour of dairy cows using a moving average based on output from an accelerometer

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Pedersen, Asger Roer; Herskin, Mette S

    2010-01-01

    in sequences of approximately 20 s for the period of 10 min. Afterwards the cows were stimulated to move/lift the legs while standing in a cubicle. The behaviour was video recorded, and the recordings were analysed second by second for walking and standing behaviour as well as the number of steps taken....... Various algorithms for predicting walking/standing status were compared. The algorithms were all based on a limit of a moving average calculated by using one of two outputs of the accelerometer, either a motion index or a step count, and applied over periods of 3 or 5 s. Furthermore, we investigated...... the effect of additionally applying the rule: a walking period must last at least 5 s. The results indicate that the lowest misclassification rate (10%) of walking and standing was obtained based on the step count with a moving average of 3 s and with the rule applied. However, the rate of misclassification...

  5. 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.

  6. 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.

  7. Does a crouched leg posture enhance running stability and robustness?

    Science.gov (United States)

    Blum, Yvonne; Birn-Jeffery, Aleksandra; Daley, Monica A; Seyfarth, Andre

    2011-07-21

    Humans and birds both walk and run bipedally on compliant legs. However, differences in leg architecture may result in species-specific leg control strategies as indicated by the observed gait patterns. In this work, control strategies for stable running are derived based on a conceptual model and compared with experimental data on running humans and pheasants (Phasianus colchicus). From a model perspective, running with compliant legs can be represented by the planar spring mass model and stabilized by applying swing leg control. Here, linear adaptations of the three leg parameters, leg angle, leg length and leg stiffness during late swing phase are assumed. Experimentally observed kinematic control parameters (leg rotation and leg length change) of human and avian running are compared, and interpreted within the context of this model, with specific focus on stability and robustness characteristics. The results suggest differences in stability characteristics and applied control strategies of human and avian running, which may relate to differences in leg posture (straight leg posture in humans, and crouched leg posture in birds). It has been suggested that crouched leg postures may improve stability. However, as the system of control strategies is overdetermined, our model findings suggest that a crouched leg posture does not necessarily enhance running stability. The model also predicts different leg stiffness adaptation rates for human and avian running, and suggests that a crouched avian leg posture, which is capable of both leg shortening and lengthening, allows for stable running without adjusting leg stiffness. In contrast, in straight-legged human running, the preparation of the ground contact seems to be more critical, requiring leg stiffness adjustment to remain stable. Finally, analysis of a simple robustness measure, the normalized maximum drop, suggests that the crouched leg posture may provide greater robustness to changes in terrain height

  8. 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.

  9. 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,

  10. Test-retest reliability of maximal leg muscle power and functional performance measures in patients with severe osteoarthritis (OA)

    DEFF Research Database (Denmark)

    Villadsen, Allan; Roos, Ewa M.; Overgaard, Søren

    Abstract : Purpose To evaluate the reliability of single-joint and multi-joint maximal leg muscle power and functional performance measures in patients with severe OA. Background Muscle power, taking both strength and velocity into account, is a more functional measure of lower extremity muscle...... and scheduled for unilateral total hip (n=9) or knee (n=11) replacement. Patients underwent a test battery on two occasions separated by approximately one week (range 7 to 11 days). Muscle power was measured using: 1. A linear encoder, unilateral lower limb isolated single-joint dynamic movement, e.g. knee...... flexion 2. A leg extension press, unilateral multi-joint knee and hip extension Functional performance was measured using: 1. 20 m walk usual pace 2. 20 m walk maximal pace 3. 5 times chair stands 4. Maximal number of knee bends/30sec Pain was measured on a VAS prior to and after conducting the entire...

  11. 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 ...

  12. 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.

  13. 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.

  14. Approach to leg edema

    Directory of Open Access Journals (Sweden)

    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.

  15. QUANTITATIVE AND QUALITATIVE DIFFERENCES OF MORPHOLOGICAL CHARACTERISTICS AND EXPLOSIVE STRENGTH OF LEGS IN UNDER-16 FEMALE AND MALE VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Slobodan Andrašić

    2015-05-01

    Full Text Available In order to achieve an advantage over the opponent, all the game elements, for which it is possible, are tended to be performed by jumping (Ziv & Lidor, 2010. This is supported by the fact that research of vertical jumping ability of volleyball players of different levels, found that players at a higher level of competition also achieve better results on tests of the assessment of vertical jumping ability (Forthomme, Croisier, Ciccarone, Crielaard, & Cloes, 2005. The research subject was aimed at detecting the difference between male and female volleyball players in morphological characteristics and explosive strength of legs, as well as determining the size of the impact of morphological characteristics of the explosive power of the lower limbs between groups formed on the basis of gender dimorphism. Method: The sample in this study was derived from a population of volleyball players of OK “RFU” from Futog, N=27 and female volleyball players of ŽOK “Futog” from Futog, N=38. For the purposes of this research morphological characteristics were measured. By using MANOVA and ANOVA differences were determined between the two sub-samples of respondents formed on the basis of gender dimorphism regarding the analyzed morphological and motor variables. In order to determine effects of the system of predictor variables on the criteria variables we used Linear Regression Analysis. Results: Statistically significant differences were observed for the variables Body height, Legs length and Lower-leg circumference, as well as for all three motor variables: Spike jump, Standing triple jump and Standing vertical jump in favor of volleyball players. Linear Regression Analysis revealed the impact of the predictor system of morphological characteristics on the criterion Spike jump in both subsamples. It was found that Body height gives the highest contribution to achieving better results regarding the height reached during spike jump in both groups

  16. 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.

  17. 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

  18. Patients with sacroiliac joint dysfunction exhibit altered movement strategies when performing a sit-to-stand task.

    Science.gov (United States)

    Capobianco, Robyn A; Feeney, Daniel F; Jeffers, Jana R; Nelson-Wong, Erika; Morreale, Joseph; Grabowski, Alena M; Enoka, Roger M

    2018-04-03

    The ability to rise from a chair is a basic functional task that is frequently compromised in individuals diagnosed with orthopedic disorders in the low back and hip. There is no published literature that describes how this task is altered by sacroiliac joint dysfunction (SIJD). The objective of this study was to compare lower extremity biomechanics and the onset of muscle activity when rising from a chair in subjects with SIJD and in healthy persons. Six women with unilateral SIJD and six age-matched healthy controls performed a sit-to-stand task while we measured kinematics, kinetics, and muscle activity. Subjects stood up at a preferred speed from a seated position on an armless and backless adjustable stool. We measured kinematics with a 10-camera motion capture system, ground reaction forces for each leg with force plates, and muscle activity with surface electromyography. Joint angles and torques were calculated using inverse dynamics. Leg-loading rate was quantified as the average slope of vertical ground reaction (VGRF) force during the 500-millisecond interval preceding maximal knee extension. Between-leg differences in loading rates and peak VGRFs were significantly greater for the SIJD group than for the control group. Maximal hip angles were significantly less for the SIJD group (p=.001). Peak hip moment in the SIJD group was significantly greater in the unaffected leg (0.75±0.22 N⋅m/kg) than in the affected leg (0.47±0.29 N⋅m/kg, p=.005). There were no between-leg or between-group differences for peak knee or ankle moments. The onset of activity in the latissimus dorsi muscle on the affected side was delayed and the erector spinae muscles were activated earlier in the SIJD group than in the control group. Subjects with SIJD have a greater VGRF on the unaffected leg, generate a greater peak hip moment in the unaffected leg, use a smaller range of motion at the hip joint of the affected leg, and delay the onset of a key muscle on the affected

  19. 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

  20. The effect of medial arch support over the plantar pressure and triceps surae muscle strength after prolonged standing

    Directory of Open Access Journals (Sweden)

    Hindun Saadah

    2015-11-01

    Full Text Available Background: The activity with prolonged standing position is one of the causes of abnormalities in the lower leg and foot. The aim of this study is to discover the effect of medial arch support over the distribution of plantar pressure when standing and walking.Methods: This was an experimental study with pre- and post-design the strength of triceps surae muscle after prolonged standing, was also evaluated in an experimental study with pre- and post-design. Variables of plantar pressure measurement are the contact area and pressure peak were measured by using the Mat-scan tool. The measurement of the triceps surae muscle strength was done with a hand-held dynamometer, before and after using the medial arch support. Measurement was performed before and after working with prolonged standing position which took place about seven hours using the medial arch support inserted in the shoes. Data was analyzed using paired T-test.Results: There was a significant difference of peak pressure between standing (p = 0.041 and walking (p = 0.001. Whereas the contact area showed a significant decrease in the width of the contact area when standing (104.12 ± 12.42 vs 99.08 ± 10.21 p = 0.023. Whereas, the triceps surae muscle strength pre- and post-standing prolonged did not indicate a significant difference.Conclusion: There was decrease in peak pressure when standing and walking and decrease in contact area when standing on plantar after used of the medial arch support after prolonged standing.

  1. Cockroaches traverse crevices, crawl rapidly in confined spaces, and inspire a soft, legged robot

    Science.gov (United States)

    Jayaram, Kaushik; Full, Robert J.

    2016-01-01

    Jointed exoskeletons permit rapid appendage-driven locomotion but retain the soft-bodied, shape-changing ability to explore confined environments. We challenged cockroaches with horizontal crevices smaller than a quarter of their standing body height. Cockroaches rapidly traversed crevices in 300–800 ms by compressing their body 40–60%. High-speed videography revealed crevice negotiation to be a complex, discontinuous maneuver. After traversing horizontal crevices to enter a vertically confined space, cockroaches crawled at velocities approaching 60 cm⋅s−1, despite body compression and postural changes. Running velocity, stride length, and stride period only decreased at the smallest crevice height (4 mm), whereas slipping and the probability of zigzag paths increased. To explain confined-space running performance limits, we altered ceiling and ground friction. Increased ceiling friction decreased velocity by decreasing stride length and increasing slipping. Increased ground friction resulted in velocity and stride length attaining a maximum at intermediate friction levels. These data support a model of an unexplored mode of locomotion—“body-friction legged crawling” with body drag, friction-dominated leg thrust, but no media flow as in air, water, or sand. To define the limits of body compression in confined spaces, we conducted dynamic compressive cycle tests on living animals. Exoskeletal strength allowed cockroaches to withstand forces 300 times body weight when traversing the smallest crevices and up to nearly 900 times body weight without injury. Cockroach exoskeletons provided biological inspiration for the manufacture of an origami-style, soft, legged robot that can locomote rapidly in both open and confined spaces. PMID:26858443

  2. 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 ...

  3. 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 ...

  4. 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.

  5. Joint Coordination and Muscle Activities of Ballet Dancers During Tiptoe Standing.

    Science.gov (United States)

    Tanabe, Hiroko; Fujii, Keisuke; Kouzaki, Motoki

    2017-01-01

    We aimed to investigate joint coordination of lower limbs in dancers during tiptoe standing and the relationship between joint coordination and muscle coactivation. Seven female ballet dancers performed tiptoe standing with six leg positions (fi e classical dance positions and one modern dance position) for 10 s. The kinematic data of the metatarsophalangeal (MP), ankle, knee, and hip joints was collected, and surface electromyography (EMG) of over 13 lower limb muscles was conducted. Principal component analysis was performed to determine joint coordination. MP-ankle and ankle-knee had in-phase coordination, whereas knee-hip showed anti-phase coordination in the sagittal plane. In addition, most EMG-EMG coherence around the MP and ankle joints was significant up to 50 Hz when these two joints swayed with in-phase. This suggests that different joint coordination patterns are associated with neural processing related to different muscle coactivation patterns. In conclusion, ballet dancers showed in-phase coordination from the MP to knee joints, which was associated with muscle coactivation to a higher frequency domain (up to 50 Hz) in comparison with anti-phase coordination.

  6. 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.

  7. 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.

  8. 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...

  9. Six weeks' aerobic retraining after two weeks' immobilization restores leg lean mass and aerobic capacity but does not fully rehabilitate leg strenght in young and older men

    DEFF Research Database (Denmark)

    Vigelsø Hansen, Andreas; Gram, Martin; Wiuff, Caroline

    2015-01-01

    OBJECTIVE: To determine the effect of aerobic retraining as rehabilitation after short-term leg immobilization on leg strength, leg work capacity, leg lean mass, leg muscle fibre type composition and leg capillary supply, in young and older men. SUBJECTS AND DESIGN: Seventeen young (23 ± 1 years...... immobilization had marked effects on leg strength, and work capacity and 6 weeks' retraining was sufficient to increase, but not completely rehabilitate, muscle strength, and to rehabilitate aerobic work capacity and leg lean mass (in the young men)....

  10. Elastic stockings effect on leg volume variability in healthy workers under prolonged gravitational gradient exposure

    Directory of Open Access Journals (Sweden)

    Mirko Tessari

    2015-06-01

    Full Text Available The aim of this study was to determine the elastic stockings effect on healthy workers (HW who are exposed to a prolonged hydrostatic pressure overload for professional reasons. The cohort was composed by 20 HW who voluntarily underwent a water plethysmography test before and after eight hour of standing up in an operating room, wearing elastic stockings. After 8 h of gravity exposure, we demonstrated the absence of leg volume increase in case of elastic stockings use. In the morning measurement we found that the lower limb volume was 1967.5 mL±224, while in the evening it was 1962.5 mL±227 (P<0.0828. The decreased volume is significantly correlated with the time that was spent under gravity forces for working purpose wearing elastic stockings (R2=0.99, P<0.0001. Our experiment demonstrates that elastic stockings may effectively counteract the increased leg volume over time in workers who are exposed to prolonged gravitational gradient. Further longitudinal studies are needed to determine if the above effect could correct one of the major risk factors for the development of chronic venous insufficiency.

  11. 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.

  12. 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.

  13. 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...

  14. 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 ...

  15. 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.

  16. 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...

  17. 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...

  18. 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

  19. 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.

  20. 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...

  1. 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.

  2. Modifications of baropodograms after transcutaneous electric stimulation of the abductor hallucis muscle in humans standing erect.

    Science.gov (United States)

    Gaillet, Jean-Claude; Biraud, Jean-Claude; Bessou, Monique; Bessou, Paul

    2004-12-01

    Objective data on abductor hallucis muscle biomechanical function in the loaded foot (subject standing erect on both legs) are unavailable. To evaluate the effects of electrical stimulation of the abductor hallucis muscle in the loaded foot on the change of plantar pressures, as measured by digital baropodograms. Six indices were defined to compare baropodograms. The abductor hallucis muscle in 1 foot was subjected to transcutaneous electrical stimulation (20 min) while the subject was standing erect on the floor. Baropodograms were recorded before, immediately thereafter, then 15 days and 2 months later. Differences between baropodogram indices were subjected to one-way anova. Electrical abductor hallucis muscle stimulation induced, on the stimulation side, a post-contraction state easily detected on baropodograms as the increased plantar pressure on the anterior-medial part of the sole, and lateral displacements of the anterior maximal pressure point and the foot thrust center. These mechanical signs, consistent with foot inversion, induce external rotation of the leg and pelvic rotation on the stimulated side, leading to contralateral plantar-pressure changes: decreased maximal pressure point and thrust in the posterior part of the footprint and lateral displacement of the foot thrust center. Electrical stimulation of the abductor hallucis muscle in the loaded foot induces immediate specific changes in baropodogram indices, some of which persist 2 months later. The mechanical effect of abductor hallucis muscle stimulation (foot inversion) and its post-contraction state could be useful in podiatric and postural rehabilitation.

  3. 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.)

  4. Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis

    Directory of Open Access Journals (Sweden)

    Nunley PD

    2017-09-01

    Full Text Available Pierce D Nunley,1 Vikas V Patel,2 Douglas G Orndorff,3 William F Lavelle,4 Jon E Block,5 Fred H Geisler6 1Spine Institute of Louisiana, Shreveport, LA, 2The Spine Center, University of Colorado Hospital, Denver, CO, 3Spine Colorado, Mercy Regional Hospital, Durango, CO, 4Upstate Bone and Joint Center, East Syracuse, NY, 5Independent Consultant, San Francisco, CA, 6Independent Consultant, Chicago, IL, USA Background: Lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis.Methods: This study evaluated the 5-year clinical outcomes for IPD (Superion® from a randomized controlled US Food and Drug Administration (FDA noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ symptom severity (ss, physical function (pf, and patient satisfaction (ps subdomains, leg and back pain visual analog scale (VAS, and Oswestry Disability Index (ODI.Results: At 5 years, 84% of patients (74 of 88 demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88, 81% (71 of 88, and 90% (79 of 88 for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85 and 65% (55 of 85, respectively, and the success rate for ODI was 65% (57 of 88. Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P<0.001. Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P<0.0001. Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years.Conclusion: After 5 years of follow-up, IPD with a stand-alone spacer provides

  5. Timing of muscle response to a sudden leg perturbation: comparison between adolescents and adults with Down syndrome.

    Directory of Open Access Journals (Sweden)

    Maria Stella Valle

    Full Text Available Movement disturbances associated with Down syndrome reduce mechanical stability, worsening the execution of important tasks such as walking and upright standing. To compensate these deficits, persons with Down syndrome increase joint stability modulating the level of activation of single muscles or producing an agonist-antagonist co-activation. Such activations are also observed when a relaxed, extended leg is suddenly released and left to oscillate passively under the influence of gravity (Wartenberg test. In this case, the Rectus femoris of adults with Down syndrome displayed peaks of activation after the onset of the first leg flexion. With the aim to verify if these muscular reactions were acquired during the development time and to find evidences useful to give them a functional explanation, we used the Wartenberg test to compare the knee joint kinematics and the surface electromyography of the Rectus femoris and Biceps femoris caput longus between adolescents and adults with Down syndrome. During the first leg flexion, adolescents and adults showed single Rectus femoris activations while, a restricted number of participants exhibited agonist-antagonist co-activations. However, regardless the pattern of activation, adults initiated the muscle activity significantly later than adolescents. Although most of the mechanical parameters and the total movement variability were similar in the two groups, the onset of the Rectus femoris activation was well correlated with the time of the minimum acceleration variability. Thus, in adolescents the maximum mechanical stability occurred short after the onset of the leg fall, while adults reached their best joint stability late during the first flexion. These results suggest that between the adolescence and adulthood, persons with Down syndrome explore a temporal window to select an appropriate timing of muscle activation to overcome their inherent mechanical instability.

  6. 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....

  7. 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...

  8. 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.

  9. 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

  10. Laterality of the legs in young female soccer players

    Directory of Open Access Journals (Sweden)

    Antosiak-Cyrak Katarzyna Z.

    2015-12-01

    Full Text Available Purpose. The aim of the present study was assessment of laterality of the legs of young female soccer players and their non-training counterparts. Methods. The study sample comprised 9 female soccer players and 19 non-training girls. They underwent three measurement sessions, one every six months. The applied tests included kinesthetic differentiation, rate of local movements, static balance, single-leg hop, rate of global movements, strength and speed, and functional asymmetry of the legs tests. Results. The soccer players were better than the controls in their performance of the rate of local movements, rate of global movements, kinesthetic differentiation, single-leg 15m timed hop and static balance tests. Smaller differences between the results of the left and the right legs in soccer players, than in non-training girls, were noted in the rate of local movements, rate of global movements and kinesthetic differentiation tests. In the static balance test, the differences were greater in the group of soccer players. Conclusions. Lateralization of the lower limbs is a highly complex characteristic with a different variability in athletes than in nontraining individuals. The results of the present study also point to the specialization of soccer players’ left legs in body balance and single-leg hop tests.

  11. 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 .

  12. 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 ...

  13. 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)

  14. [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.

  15. Validity and reliability of the Nintendo Wii Balance Board for assessment of standing balance.

    Science.gov (United States)

    Clark, Ross A; Bryant, Adam L; Pua, Yonghao; McCrory, Paul; Bennell, Kim; Hunt, Michael

    2010-03-01

    Impaired standing balance has a detrimental effect on a person's functional ability and increases their risk of falling. There is currently no validated system which can precisely quantify center of pressure (COP), an important component of standing balance, while being inexpensive, portable and widely available. The Wii Balance Board (WBB) fits these criteria, and we examined its validity in comparison with the 'gold standard'-a laboratory-grade force platform (FP). Thirty subjects without lower limb pathology performed a combination of single and double leg standing balance tests with eyes open or closed on two separate occasions. Data from the WBB were acquired using a laptop computer. The test-retest reliability for COP path length for each of the testing devices, including a comparison of the WBB and FP data, was examined using intraclass correlation coefficients (ICC), Bland-Altman plots (BAP) and minimum detectable change (MDC). Both devices exhibited good to excellent COP path length test-retest reliability within-device (ICC=0.66-0.94) and between-device (ICC=0.77-0.89) on all testing protocols. Examination of the BAP revealed no relationship between the difference and the mean in any test, however the MDC values for the WBB did exceed those of the FP in three of the four tests. These findings suggest that the WBB is a valid tool for assessing standing balance. Given that the WBB is portable, widely available and a fraction of the cost of a FP, it could provide the average clinician with a standing balance assessment tool suitable for the clinical setting. Copyright 2009 Elsevier B.V. All rights reserved.

  16. 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

  17. 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.

  18. 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.)

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. The Effect of Various Standing Positions in Muscles Activity between Healthy Young Men and those with Genu Varum

    Directory of Open Access Journals (Sweden)

    Persian Abstract Amir Hossein Barati

    2015-09-01

    Full Text Available Objective: Genu varum is considered a risk factor for knee osteoarthritis. Being aware of the changes in muscles activity in various standing positions among genu varum patients, can provide insight for preventing osteoarthritis in this population. This study is undertaken to compare muscles activity in various standing positions between young healthy and genu varum male individuals. Methods: 80 healthy male university students, 40 normal and 40 subjects with genu varum deformity, participated in this study. Deformity of genu varum was assessed with caliper and Goniometer. Each subject stood in five different positions and muscles activity was recorded with EMG device. For data analysis, Matlab and SPSS software were employed and Mixed variance analysis test (Mixed ANOVA was run to compare the dependent variables at a significance level of P ≤ 0.05. Results: Significant differences were observed between the two groups for muscles activity of the tensor fasia latae (at single leg with closed eye position, tertius fibulae and gluteus medius muscles (at single leg with closed eye and upward head postions( p≤0.05 while no significant differences were observed in other muscles. Conclusion: According to the obtained results, it can be suggested that frontal knee angle may affect muscles activity. Perhaps one of the reasons for higher injury risk and knee osteoarthritis in genu varum population is the increase in muscles activity. Therefor, It is proposed that focusing on corrective exercises can reduce these risks.

  5. 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.

  6. Introducing sit-stand desks increases classroom standing time among university students

    Directory of Open Access Journals (Sweden)

    Matthew Jerome

    2017-12-01

    Full Text Available Excessive sedentary behavior has been associated with many negative health outcomes. While an understudied health topic, there is evidence that university students are excessively sedentary. Sit-stand desks have been shown to reduce sedentary time among pre-university students (ages 5–18years and sedentary workers but have not been tested in university classrooms. This study tested the effects of introducing sit-stand desks into a university classroom on student's classroom sitting and standing behaviors. Using a cross-over design, students received access to both traditional seated desks and sit-stand desks for six weeks. Data were collected between September and December, 2016. We recruited 304 healthy undergraduate university students enrolled in one of two small (25 seats classrooms at a large Midwestern university during the fall of 2016. Average minutes of standing/hour/student, average percent class time spent standing, and the number of sit-stand transitions/student/hour were directly observed with video camera surveillance. Participants stood significantly more (p<0.001 when provided access to sit-stand desks (7.2min/h/student; 9.3% of class time spent standing compared to when they had access to seated desks (0.7min/h/student; 1.6% of class time spent standing but no differences were observed for the number of sit-stand transitions (p=0.47. Students reported high favorability for the sit-stand desks and improvements in several student engagement and affective outcomes while using the sit-stand desks. These findings support introducing sit-stand desks in university classrooms as an approach to reduce sedentary behaviors of university students. Keywords: Sedentary, University students, Sit-stand desk

  7. 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)

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. 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.

  13. 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....

  14. Standing footprint diagnostic method

    Science.gov (United States)

    Fan, Y. F.; Fan, Y. B.; Li, Z. Y.; Newman, T.; Lv, C. S.; Fan, Y. Z.

    2013-10-01

    Center of pressure is commonly used to evaluate standing balance. Even though it is incomplete, no better evaluation method has been presented. We designed our experiment with three standing postures: standing with feet together, standing with feet shoulder width apart, and standing with feet slightly wider than shoulder width. Our platform-based pressure system collected the instantaneous plantar pressure (standing footprint). A physical quantity of instantaneous standing footprint principal axis was defined, and it was used to construct an index to evaluate standing balance. Comparison between results from our newly established index and those from the center of pressure index to evaluate the stability of different standing postures revealed that the standing footprint principal axis index could better respond to the standing posture change than the existing one. Analysis indicated that the insensitive response to the relative position between feet and to the standing posture change from the center of pressure could be better detected by the standing footprint principal axis index. This predicts a wide application of standing footprint principal axis index when evaluating standing balance.

  15. 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.

  16. 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.

  17. Control of vertical posture while standing on a sliding board and pushing an object.

    Science.gov (United States)

    Lee, Yun-Ju; Chen, Bing; Liang, Jing-Nong; Aruin, Alexander S

    2018-03-01

    Voluntary pushing or translation perturbation of the support surface each induces a body perturbation that affects postural control. The objective of the study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments when pushing an object (that induces self-initiated perturbation) and standing on a sliding board (that induces translational perturbation). Thirteen healthy young participants were instructed to push a handle with both hands while standing on a sliding board that was either free to move in the anterior-posterior direction or stationary. Electromyographic activity (EMG) of trunk and lower extremity muscles, center of pressure (COP) displacements, and the forces exerted by the hand were recorded and analyzed during the APA and CPA phases. When the sliding board was free to move during pushing (translation perturbation), onsets of activity of ventral leg muscles and COP displacement were delayed as compared to pushing when standing on a stationary board. Moreover, magnitudes of shank muscle activity and the COP displacement were decreased. When pushing heavier weight, magnitudes of muscle activity, COP displacement, and pushing force increased. The magnitude of activity of the shank muscles during the APA and CPA phases in conditions with translational perturbation varied with the magnitude of the pushing weight. The outcome of the study suggests that the central nervous system prioritizes the pushing task while attenuates the source of additional perturbation induced by translation perturbation. These results could be used in the development of balance re-training paradigms involving pushing weight while standing on a sliding surface.

  18. 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

  19. 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...

  20. Lower extremity fatigue increases complexity of postural control during a single-legged stance

    Directory of Open Access Journals (Sweden)

    Bailey Jerry J

    2011-08-01

    Full Text Available Abstract Background Non-linear approaches to assessment of postural control can provide insight that compliment linear approaches. Control entropy (CE is a recently developed statistical tool from non-linear dynamical systems used to assess the complexity of non-stationary signals. We have previously used CE of high resolution accelerometry in running to show decreased complexity with exhaustive exercise. The purpose of this study was to determine if complexity of postural control decreases following fatiguing exercise using CE. Methods Ten subjects (5 M/5 F; 25 ± 3 yr; 169.4 ± 11.7 cm; 79.0 ± 16.9 kg consented to participation approved by Western Oregon University IRB and completed two trials separated by 2-7 days. Trials consisted of two single-legged balance tests separated by two Wingate anaerobic tests (WAnT; PreFat/PostFat, or rest period (PreRest/PostRest. Balance tests consisted of a series of five single-legged stances, separated by 30 s rest, performed while standing on the dominant leg for 15-s with the participant crossing the arms over the chest and flexing the non-dominant knee to 90 degrees. High resolution accelerometers (HRA were fixed superficial to L3/L4 at the approximate center of mass (COM. Triaxial signals from the HRA were streamed in real time at 625 Hz. COM accelerations were recorded in g's for vertical (VT, medial/lateral (ML, and anterior/posterior (AP axes. A newly developed statistic (R-test was applied to group response shapes generated by Karhunen Loeve (KL transform modes resulting from Control Entropy (CE analysis. Results R-tests showed a significant mean vector difference (p p p p Conclusions These data indicate that fatiguing exercise eliminates the differential complexity response between axes, but increases complexity in all axes compared to the non-fatigued condition. This has implications with regard to the effects of fatigue on strategies of the control system to maintain postural control.

  1. 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.

  2. 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.

  3. 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

  4. 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....

  5. 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.

  6. 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.

  7. Reliability of System Identification Techniques to Assess Standing Balance in Healthy Elderly.

    Directory of Open Access Journals (Sweden)

    Jantsje H Pasma

    Full Text Available System identification techniques have the potential to assess the contribution of the underlying systems involved in standing balance by applying well-known disturbances. We investigated the reliability of standing balance parameters obtained with multivariate closed loop system identification techniques.In twelve healthy elderly balance tests were performed twice a day during three days. Body sway was measured during two minutes of standing with eyes closed and the Balance test Room (BalRoom was used to apply four disturbances simultaneously: two sensory disturbances, to the proprioceptive and the visual system, and two mechanical disturbances applied at the leg and trunk segment. Using system identification techniques, sensitivity functions of the sensory disturbances and the neuromuscular controller were estimated. Based on the generalizability theory (G theory, systematic errors and sources of variability were assessed using linear mixed models and reliability was assessed by computing indexes of dependability (ID, standard error of measurement (SEM and minimal detectable change (MDC.A systematic error was found between the first and second trial in the sensitivity functions. No systematic error was found in the neuromuscular controller and body sway. The reliability of 15 of 25 parameters and body sway were moderate to excellent when the results of two trials on three days were averaged. To reach an excellent reliability on one day in 7 out of 25 parameters, it was predicted that at least seven trials must be averaged.This study shows that system identification techniques are a promising method to assess the underlying systems involved in standing balance in elderly. However, most of the parameters do not appear to be reliable unless a large number of trials are collected across multiple days. To reach an excellent reliability in one third of the parameters, a training session for participants is needed and at least seven trials of two

  8. The Sit & Stand chair. A revolutionary advance in adaptive seating systems.

    Science.gov (United States)

    Galumbeck, Michael H; Buschbacher, Ralph M; Wilder, Robert P; Winters, Kathryne L; Hudson, Mary Anne; Edlich, Richard F

    2004-01-01

    A major factor governing independence for the elderly and persons with disabilities is the ability to stand from a chair. Factors such as pain, reduced joint range of motion, stiffness, and muscle weakness frequently limit the ability to stand. Sit-to-stand position is even further reduced in patients whose hands and shoulders are afflicted with rheumatoid arthritis. When achieving a sit-to-stand position in the elderly and persons with disabilities, there is considerable risk of the individual falling and sustaining bone fracture. The purposes of this scientific report are to achieve the following goals: (1) to provide a narrative discussion of the senior author's contributions to furniture manufacturing as well as his successful patent application for the SIT & STAND chair, (2) to describe the steps involved in the development of the SIT & STAND prototype, and (3) to examine the performance of the SIT & STAND chair in assisting the elderly or persons with disabilities in achieving a sit-to-stand position. The invention of the SIT & STAND chair by the senior author, Michael Galumbeck, was a culmination of his lifelong interest in adaptive seating systems. His electrically operated chair has the unique ability to assist the occupant to achieve safely a sit-to-stand position. The rear portion of his chair remains in a fixed position to support the buttocks of the user during mechanical lift. The front portion of the seat folds down incrementally as the chair rises to allow the feet of the user to be positioned in a more posterior position firmly on the floor. Using its actuator, the height that the chair rises will vary with the length of the legs of the occupant. Using the drawing program Solid Works (Solid Works, Concord, Massachusetts), drawings of the chair were made. To visualize the operation and performance of the chair, separate drawings were made in the lateral position. The prototype of the SIT & STAND chair was manufactured with an electric actuator that

  9. Correlation between movement complexity during static standing and balance function in institutionalized older adults

    Directory of Open Access Journals (Sweden)

    Yamagata M

    2017-03-01

    Full Text Available Momoko Yamagata,1 Tome Ikezoe,1 Midori Kamiya,1 Mitsuhiro Masaki,2,3 Noriaki Ichihashi1 1Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, 2Department of Physical Therapy, 3Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan Purpose: Sample entropy (SampEn is an analysis to evaluate movement complexity of the center of pressure (COP. A lower value of SampEn indicates lower complexity of COP variability, that is, rigidity, and lower degrees of freedom. Previous studies reported the association of increased SampEn with improved standing balance ability in young subjects. However, no studies have examined these relationships among older adults. Thus, we aimed to investigate the relationship between SampEn and standing balance ability in older adults.Subjects and methods: The subjects were 33 institutionalized older adults (aged 82.2±6.5 years. COP during static standing was measured. The standard deviation (SD values of COP and SampEn in the sagittal and frontal planes were calculated using time series data. One-leg standing test (OLST, functional reach (FR test, and lateral reach (LR test were also measured to evaluate standing balance ability.Results: OLST, FR, and LR were 6.5±8.3 s, 19.8±5.9 cm, and 18.2±6.4 cm, respectively. Pearson correlation analysis revealed that SampEn in the sagittal plane significantly correlated with OLST (r=-0.35 and FR (r=-0.36. However, SampEn in the frontal plane and SD of COP in both sagittal and frontal planes had no relationship with any of the clinical balance tests.Conclusion: Lower SampEn implies rigidity for postural control. In the present study, it was found that lower SampEn in the sagittal plane was related to a higher balance function, which suggests that older adults utilized body rigidity to maintain postural stability as a compensative strategy. Keywords: older adults, posture, balance, standing, complexity

  10. [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.

  11. 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 …

  12. 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.

  13. 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.

  14. 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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

  16. Roll type conducting polymer legs for rigid-flexible thermoelectric generator

    Directory of Open Access Journals (Sweden)

    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.

  17. Support surface related changes in feedforward and feedback control of standing posture.

    Science.gov (United States)

    Mohapatra, Sambit; Kukkar, Komal K; Aruin, Alexander S

    2014-02-01

    The aim of the study was to investigate the effect of different support surfaces on feedforward and feedback components of postural control. Nine healthy subjects were exposed to external perturbations applied to their shoulders while standing on a rigid platform, foam, and wobble board with eyes open or closed. Electrical activity of nine trunk and leg muscles and displacements of the center of pressure were recorded and analyzed during the time frames typical of feedforward and feedback postural adjustments. Feedforward control of posture was characterized by earlier activation of anterior muscles when the subjects stood on foam compared to a wobble board or a firm surface. In addition, the magnitude of feedforward muscle activity was the largest when the foam was used. During the feedback control, anterior muscles were activated prior to posterior muscles irrespective of the nature of surface. Moreover, the largest muscle activity was seen when the supporting surface was foam. Maximum CoP displacement occurred when subjects were standing on a rigid surface. Altering support surface affects both feedforward and feedback components of postural control. This information should be taken into consideration in planning rehabilitation interventions geared towards improvement of balance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Hereditary Lymphedema of the Leg – A Case Report

    Directory of Open Access Journals (Sweden)

    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.

  19. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  20. 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.

  1. CALCANEAL MINERAL DENSITY IN CHILDREN ATHLETES AND TAKE-OFF LEG

    Directory of Open Access Journals (Sweden)

    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.

  2. 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.

  3. 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...

  4. Influence of Transcranial Direct Current Stimulation to the Cerebellum on Standing Posture Control

    Directory of Open Access Journals (Sweden)

    Yasuto Inukai

    2016-07-01

    Full Text Available Damage to the vestibular cerebellum results in dysfunctional standing posture control. Patients with cerebellum dysfunction have a larger sway in the center of gravity while standing compared with healthy subjects. Transcranial direct current stimulation (tDCS is a noninvasive technique for selectively exciting or inhibiting specific neural structures with potential applications in functional assessment and treatment of neural disorders. However, the specific stimulation parameters for influencing postural control have not been assessed. In this study, we investigated the influence of tDCS when applied over the cerebellum on standing posture control. Sixteen healthy subjects received tDCS (20 min, 2 mA over the scalp 2 cm below the inion. In experiment 1, all 16 subjects received tDCS under three stimulus conditions, Sham, Cathodal, and Anodal, in a random order with the second electrode placed on the forehead. In experiment 2, five subjects received cathodal stimulation only with the second electrode placed over the right buccinator muscle. Center of gravity sway was measured twice for 60 s before and after tDCS in a standing posture with eyes open and legs closed, and average total locus length, locus length per second, rectangular area, and enveloped area were calculated. In experiment 1, total locus length and locus length per second decreased significantly after cathodal stimulation but not after anodal or sham stimulation, while no tDCS condition influenced rectangular or enveloped areas. In experiment 2, cathodal tDCS again significantly reduced total locus length and locus length per second but not rectangular and enveloped areas. The effects of tDCS on postural control are polarity-dependent, likely reflecting the selective excitation or inhibition of cerebellar Purkinje cells. Cathodal tDCS to the cerebellum of healthy subjects can alter body sway (velocity.

  5. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  7. The ambiguity of standing in standing devices: a qualitative interview study concerning children and parents experiences of the use of standing devices.

    Science.gov (United States)

    Nordström, Birgitta; Näslund, Annika; Ekenberg, Lilly; Zingmark, Karin

    2014-10-01

    The aim of this study was to describe children's and parents' experiences of the significance of standing in a standing device. Individual interviews were performed with six children/teenagers (aged 7-19 years) and 14 parents. The interviews were transcribed and analyzed using a qualitative content analysis. The analysis resulted in the major theme, the duality of uprightness and the related themes: (1) the instrumental dimension of standing; (2) the social dimension of standing; and (3) the ambivalent dimension of standing. Each of the themes comprised several subthemes. There is an inherent duality related to the use of a standing device. Standing in a standing device was seen as a treatment of body structures and functions, as well as a possible source of pain. Standing was considered to influence freedom in activities and participation both positively and negatively. The parents experienced that standing influenced other peoples' views of their child, while the children experienced standing as a way to extend the body and as something that gave them benefits in some activities. Physiotherapists working with children should take into account both the social and physical dimensions of using a standing device and consider both the child's and the parents' views.

  8. 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....

  9. Effect of higher muscle coactivation on standing postural response to perturbation in older adults.

    Science.gov (United States)

    Nagai, Koutatsu; Okita, Yusuke; Ogaya, Shinya; Tsuboyama, Tadao

    2017-04-01

    Although several studies have reported that muscle coactivation during postural control increases with age, the effect of higher muscle coactivation on standing postural response to perturbation is unknown. To investigate whether higher muscle coactivation affects standing postural response to perturbation in older adults. Thirty-four community-dwelling older participants were randomly assigned either to the coactivation group (CG), where muscle coactivation was increased intentionally, or to the non-coactivation group (NCG). The participants were instructed to stand on a force plate that moved forward or backward. Electromyography data were collected from the lower leg muscles. We requested the participants in the CG to increase the activity of their tibialis anterior, and to maintain this posture during the tasks. We moved the force plate with a constant amplitude and velocity, and measured kinematic data with a camera during the tasks. During forward transfer, the knee extension and hip flexion decreased in the CG after perturbation compared to NCG, and the trunk extension angle increased. The center of pressure (COP) displacement decreased around the peak of the movement in the CG compared to NCG. During backward transfer, ankle dorsal and knee flexion changed after perturbation in the CG compared to NCG. Our study found that higher muscle coactivation inhibits lower limb and COP movement as well as increases trunk tilt and the risk for falls during forward perturbations. Postural control with higher coactivation appears to be inefficient for maintaining balance during the backward sway of posture.

  10. Introducing sit-stand desks increases classroom standing time among university students.

    Science.gov (United States)

    Jerome, Matthew; Janz, Kathleen F; Baquero, Barbara; Carr, Lucas J

    2017-12-01

    Excessive sedentary behavior has been associated with many negative health outcomes. While an understudied health topic, there is evidence that university students are excessively sedentary. Sit-stand desks have been shown to reduce sedentary time among pre-university students (ages 5-18 years) and sedentary workers but have not been tested in university classrooms. This study tested the effects of introducing sit-stand desks into a university classroom on student's classroom sitting and standing behaviors. Using a cross-over design, students received access to both traditional seated desks and sit-stand desks for six weeks. Data were collected between September and December, 2016. We recruited 304 healthy undergraduate university students enrolled in one of two small (25 seats) classrooms at a large Midwestern university during the fall of 2016. Average minutes of standing/hour/student, average percent class time spent standing, and the number of sit-stand transitions/student/hour were directly observed with video camera surveillance. Participants stood significantly more (p classrooms as an approach to reduce sedentary behaviors of university students.

  11. Effects of Backpack Carriage on Dual-Task Performance in Children During Standing and Walking.

    Science.gov (United States)

    Beurskens, Rainer; Muehlbauer, Thomas; Grabow, Lena; Kliegl, Reinhold; Granacher, Urs

    2016-01-01

    Primary school children perform parts of their everyday activities while carrying school supplies and being involved in attention-demanding situations. Twenty-eight children (8-10 years old) performed a 1-legged stance and a 10 m walking test under single- and dual-task situations in unloaded (i.e., no backpack) and loaded conditions (i.e., backpack with 20% of body mass). Results showed that load carriage did not significantly influence children's standing and walking performance (all p > .05), while divided attention affected all proxies of walking (all p attention interactions was detected. The single application of attentional but not load demand negatively affects children's walking performance. A combined application of both did not further deteriorate their gait behavior.

  12. Development of VariLeg, an exoskeleton with variable stiffness actuation: first results and user evaluation from the CYBATHLON 2016.

    Science.gov (United States)

    Schrade, Stefan O; Dätwyler, Katrin; Stücheli, Marius; Studer, Kathrin; Türk, Daniel-Alexander; Meboldt, Mirko; Gassert, Roger; Lambercy, Olivier

    2018-03-13

    Powered exoskeletons are a promising approach to restore the ability to walk after spinal cord injury (SCI). However, current exoskeletons remain limited in their walking speed and ability to support tasks of daily living, such as stair climbing or overcoming ramps. Moreover, training progress for such advanced mobility tasks is rarely reported in literature. The work presented here aims to demonstrate the basic functionality of the VariLeg exoskeleton and its ability to enable people with motor complete SCI to perform mobility tasks of daily life. VariLeg is a novel powered lower limb exoskeleton that enables adjustments to the compliance in the leg, with the objective of improving the robustness of walking on uneven terrain. This is achieved by an actuation system with variable mechanical stiffness in the knee joint, which was validated through test bench experiments. The feasibility and usability of the exoskeleton was tested with two paraplegic users with motor complete thoracic lesions at Th4 and Th12. The users trained three times a week, in 60 min sessions over four months with the aim of participating in the CYBATHLON 2016 competition, which served as a field test for the usability of the exoskeleton. The progress on basic walking skills and on advanced mobility tasks such as incline walking and stair climbing is reported. Within this first study, the exoskeleton was used with a constant knee stiffness. Test bench evaluation of the variable stiffness actuation system demonstrate that the stiffness could be rendered with an error lower than 30 Nm/rad. During training with the exoskeleton, both users acquired proficient skills in basic balancing, walking and slalom walking. In advanced mobility tasks, such as climbing ramps and stairs, only basic (needing support) to intermediate (able to perform task independently in 25% of the attempts) skill levels were achieved. After 4 months of training, one user competed at the CYBATHLON 2016 and was able to perform 3

  13. Eyelash Transplantation Using Leg Hair by Follicular Unit Extraction

    Directory of Open Access Journals (Sweden)

    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.

  14. Investigation of Anticipatory Postural Adjustments during One-Leg Stance Using Inertial Sensors: Evidence from Subjects with Parkinsonism.

    Science.gov (United States)

    Bonora, Gianluca; Mancini, Martina; Carpinella, Ilaria; Chiari, Lorenzo; Ferrarin, Maurizio; Nutt, John G; Horak, Fay B

    2017-01-01

    The One-Leg Stance (OLS) test is a widely adopted tool for the clinical assessment of balance in the elderly and in subjects with neurological disorders. It was previously showed that the ability to control anticipatory postural adjustments (APAs) prior to lifting one leg is significantly impaired by idiopathic Parkinson's disease (iPD). However, it is not known how APAs are affected by other types of parkinsonism, such as frontal gait disorders (FGD). In this study, an instrumented OLS test based on wearable inertial sensors is proposed to investigate both the initial anticipatory phase and the subsequent unipedal balance. The sensitivity and the validity of the test have been evaluated. Twenty-five subjects with iPD presenting freezing of gait (FOG), 33 with iPD without FOG, 13 with FGD, and 32 healthy elderly controls were recruited. All subjects wore three inertial sensors positioned on the posterior trunk (L4-L5), and on the left and right frontal face of the tibias. Participants were asked to lift a foot and stand on a single leg as long as possible with eyes open, as proposed by the mini-BESTest. Temporal parameters and trunk acceleration were extracted from sensors and compared among groups. The results showed that, regarding the anticipatory phase, the peak of mediolateral trunk acceleration was significantly reduced compared to healthy controls ( p   0.74), demonstrating the method's validity. Our findings support the validity of the proposed method for assessing the OLS test and its sensitivity in distinguishing among the tested groups. The instrumented test discriminated between healthy controls and people with parkinsonism and among the three groups with parkinsonism. The objective characterization of the initial anticipatory phase represents an interesting improvement compared to most clinical OLS tests.

  15. 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.

  16. Use of a unipedal standing test to assess the ambulation reacquisition time during the early postoperative stage after hip fracture in elderly Japanese: prospective study.

    Science.gov (United States)

    Murata, Koichi; Sugitani, Shigeki; Yoshioka, Hiroki; Noguchi, Takashi; Aoto, Toshiyuki; Nakamura, Takashi

    2010-01-01

    The aim of this study was to predict the ambulation reacquisition time after hip fracture in elderly people using the unipedal standing test during the early postoperative stage. Patients with an intertrochanteric fracture treated with internal fixation (n = 35) and patients with a femoral neck fracture treated with hemiarthroplasty (n = 22) were included. A unipedal standing test using the nonoperated leg was performed on days 3 and 7 after the operation. Among the patients with an intertrochanteric fracture, those with a positive result on the unipedal standing test on postoperative day (POD) 3 attained gait with parallel guide bars (BG) and walker-assisted gait (WG) significantly earlier than did patients with a negative result on the unipedal standing test. Patients with a positive result on the unipedal standing test on POD 7 attained BG, WG, and cane-assisted gait (CG) significantly earlier than did patients with a negative test. Among patients with a femoral neck fracture, those with a positive unipedal standing test result on POD 3 attained BG, WG, and CG significantly earlier than did patients with a negative test. Those with a positive test result on POD 7 attained BG, WG, and CG significantly earlier than did patients with a negative test. The unipedal standing test given during the early postoperative stage is a good test for predicting the ambulation reacquisition time. Moreover, it gives information that can help determine the need for subacute rehabilitation and about discharge planning and health service provision.

  17. 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

  18. Macro- and microperfusion during application of a new compression system, designed for patients with leg ulcer and concomitant peripheral arterial occlusive disease.

    Science.gov (United States)

    Jünger, Michael; Haase, Hermann; Schwenke, Linda; Bichel, Jens; Schuren, Jan; Ladwig, Andrea

    2013-01-01

    To investigate macro- and microperfusion during 14 days of treatment with a new 2-layer compression system (3M™ Coban™ 2 Lite), designed for patients with leg ulcer and concomitant peripheral arterial occlusive disease. A single-centre, open-label, prospective pilot study was performed with 15 subjects suffering from peripheral arterial occlusive disease with an ankle brachial pressure index (ABPI) of 0.5-0.8, who volunteered to have their 'study leg' bandaged with the new system. Coincident leg ulcer or chronic venous disease was not mandatory. All subjects received the new compression system, which stayed in place from 1 up to 4 days according to scheduled study visits. The system was reapplied by study personnel at each clinical visit (days 1, 2, 3, 4, 7, 10 and 14). The study participation stopped after 14 days. At each clinical visit safety assessments were performed: measurement of acral pulsation to capture macroperfusion; laser Doppler fluxmetry to capture microperfusion; clinical signs of pressure related skin damage, hypoxia-related pain and sub-bandage pressure measurement. In addition, the leg volume was measured and a comfort questionnaire was completed. An average sub-bandage pressure in standing position of approximately 30 mmHg was measured at the B1 location immediately after bandage application. Laser Doppler fluxmetry demonstrated positive effects on microcirculation regarding vasomotion and respiratory reflux. No change of the cardiac signal appeared. For acrale pulsations a high intraindividual variability was found with no clear interference to the bandage application. No pressure-related skin damage or hypoxia-related pain was detected. After application of the new compression system in subjects with moderate PAOD, laser Doppler fluxmetry indicated significant improvements of the microcirculation. High variability and lack of correlation to clinical symptoms was found for the acral pulsation. The new compression system revealed a high

  19. Stand and within-stand factors influencing Golden-winged Warbler use of regenerating stands in the central Appalachian Mountains

    Directory of Open Access Journals (Sweden)

    Marja H. Bakermans

    2015-06-01

    Full Text Available The Golden-winged Warbler (Vermivora chrysoptera is currently being considered for protected status under the U.S. Endangered Species Act. The creation of breeding habitat in the Appalachian Mountains is considered a conservation priority for this songbird, which is dependent on extensively forested landscapes with adequate availability of young forest. We modeled abundance of Golden-winged Warbler males in regenerating harvested forest stands that were 0-17 years postharvest at both mid-Appalachian and northeast Pennsylvania regional scales using stand and within-stand characteristics of 222 regenerating stands, 2010-2011. Variables that were most influential at the mid-Appalachian scale were different than those in the northeast region. Across the mid-Appalachian ecoregion, the proportion of young forest cover, i.e., shrub/scrub cover, within 1 km of regenerating stands best explained abundance of Golden-winged Warblers. Golden-winged Warbler response was best explained by a concave quadratic relationship in which abundance was highest with 5-15% land in young forest cover. We also found evidence that the amount of herbaceous cover, i.e., the amount of grasses and forbs, within a regenerating stand positively influenced abundance of Golden-winged Warblers. In northeastern Pennsylvania, where young forest cover is found in high proportions, the distance to the nearest regenerating stand best explained variation in abundance of Golden-winged Warblers. Abundance of Golden-winged Warblers was 1500 m away. When modeling within-stand features in the northeast region, many of the models were closely ranked, indicating that multiple variables likely explained Golden-winged Warbler response to within-stand conditions. Based on our findings, we have proposed several management guidelines for land managers interested in creating breeding habitat for Golden-winged Warblers using commercial timber operations. For example, we recommend when managing for

  20. 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)

  1. [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.

  2. 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

  3. 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...

  4. 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

  5. Effect of rubber flooring on dairy cattle stepping behavior and muscle activity.

    Science.gov (United States)

    Rajapaksha, Eranda; Winkler, Christoph; Tucker, Cassandra B

    2015-04-01

    Use of compressible flooring, such as rubber, has increased on dairy farms. Rubber improves locomotion and is well used by cattle in preference experiments that combine walking and standing. Previous work has found that rubber is particularly beneficial for lame animals, perhaps because a softer material is particularly useful when a single hoof is compromised. The goal of this work was to evaluate the effect of flooring while standing, because cattle in freestall housing spend 40 to 50% of their time engaged in this behavior. In a 2 × 2 design, cows (n = 16) were evaluated on 4 standing surfaces that varied in terms of both floor type (concrete or rubber) and presentation [same floor under all 4 legs (all 4 legs on either concrete or rubber) or a rough surface under only one hind leg and the other 3 legs on concrete or rubber] in a crossover design. Surface electromyograms were used to evaluate muscle fatigue, total activity, and movement of muscle activity between legs during 1 h of standing. Muscle fatigue was evaluated in 2 contexts: (1) static contractions when cows continuously transferred weight to each hind leg, before and after 1 h of standing, and (2) dynamic contractions associated with steps during 1 h on treatment surfaces. In addition, stepping rate, time between each consecutive step, and the latency to lie down after testing were measured. No interaction between floor type and presentation was found. Presentation had a significant effect; when one hind leg was on a rough surface, cattle took 1.7 times more steps with this leg and the non-rough hind leg had 1.2 times more muscle activity, compared with when all 4 legs were on the same surface. These changes are consistent with movement away from concrete with protrusions. When standing on rubber, muscle-activity movements among legs remained stable (0.6-0.7 movements per min) over 1 h but increased on concrete (0.6-0.9 movements per min), indicating that, like humans, cattle may sway to counteract

  6. 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.

  7. 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.

  8. Increase in Leg Stiffness Reduces Joint Work During Backpack Carriage Running at Slow Velocities.

    Science.gov (United States)

    Liew, Bernard; Netto, Kevin; Morris, Susan

    2017-10-01

    Optimal tuning of leg stiffness has been associated with better running economy. Running with a load is energetically expensive, which could have a significant impact on athletic performance where backpack carriage is involved. The purpose of this study was to investigate the impact of load magnitude and velocity on leg stiffness. We also explored the relationship between leg stiffness and running joint work. Thirty-one healthy participants ran overground at 3 velocities (3.0, 4.0, 5.0 m·s -1 ), whilst carrying 3 load magnitudes (0%, 10%, 20% weight). Leg stiffness was derived using the direct kinetic-kinematic method. Joint work data was previously reported in a separate study. Linear models were used to establish relationships between leg stiffness and load magnitude, velocity, and joint work. Our results found that leg stiffness did not increase with load magnitude. Increased leg stiffness was associated with reduced total joint work at 3.0 m·s -1 , but not at faster velocities. The association between leg stiffness and joint work at slower velocities could be due to an optimal covariation between skeletal and muscular components of leg stiffness, and limb attack angle. When running at a relatively comfortable velocity, greater leg stiffness may reflect a more energy efficient running pattern.

  9. 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...

  10. 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...

  11. 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.

  12. 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)

  13. 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.

  14. 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)

  15. 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)

  16. Effects of hamstring stretch with pelvic control on pain and work ability in standing workers.

    Science.gov (United States)

    Han, Hyun-Il; Choi, Ho-Suk; Shin, Won-Seob

    2016-11-21

    Hamstring tightness induces posterior pelvic tilt and decreased lumbar lordosis, which can result in low back painOBJECTIVE: We investigated effects of hamstring stretch with pelvic control on pain and work ability in standing workers. One hundred adult volunteers from a standing workers were randomly assigned to pelvic control hamstring stretching (PCHS) (n = 34), general hamstring stretching (GHS) (n = 34), control (n = 32) groups. The control group was performed self-home exercise. All interventions were conducted 3 days per week for 6 weeks, and included in the hamstring stretching and lumbopelvic muscle strengthening. Outcomes were evaluated through the visual analog scale (VAS), straight leg raise test (SLR), sit and reach test (SRT), Oswestry disability index (ODI), and work ability index (WAI). Significant difference in VAS, SLR, SRT, ODI, and WAI were found in the PCHS and GHS groups. The control group was a significant difference only in ODI. The PCHS group showed a greater difference than the GHS group and control group in VAS, SLR, SRT, and ODI. The pelvic control hamstring stretch exercise would be more helpful in back pain reduction and improvement of work ability in an industrial setting.

  17. 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

  18. 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.

  19. 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.

  20. A tactile stimulus applied to the leg improves postural stability in young, old and neuropathic subjects.

    Science.gov (United States)

    Menz, Hylton B; Lord, Stephen R; Fitzpatrick, Richard C

    2006-10-02

    The purpose of this study was to determine whether the application of passive tactile cues to the lower limb could improve postural stability in healthy young controls, older people and people with diabetic peripheral neuropathy. Antero-posterior sway was measured with eyes open and closed in 10 healthy young subjects (mean age 27 years, 5 male, 5 female), 10 older subjects without diabetic peripheral neuropathy (mean age 88 years, 2 male, 8 female) and 10 subjects with diabetic peripheral neuropathy (mean age 65 years, 6 male, 4 female) while a small piece of Velcro attached to a flexible mount was applied to three different sites on the leg (ankle, calf, and knee). Across all conditions, the mean sway of the neuropathic subjects was 93% greater than for the young subjects and 11% more than the older subjects. On average, subjects swayed 10% more with the eyes closed than with the eyes open. Each stimulus reduced sway, but the effect increased approximately in proportion to the height of the stimulus above the ankles (ankle 7.6%, calf 13.5%, knee 20.1% reduction compared to the no stimulus condition). This experiment demonstrates that a passive stimulus applied to the skin of the leg, which provides sensory information about body movement, significantly reduces body sway during standing. This applies to older subjects and subjects with peripheral neuropathy as well as healthy young subjects. These results have implications for novel approaches for improving stability in people with peripheral sensory loss.

  1. Solitude and Growth in the Consciousness of Feminism---On Aoyama Nanae’s Good Weather ofOne Person%女性意识下的孤独与成长--论青山七惠的《一个人的好天气》

    Institute of Scientific and Technical Information of China (English)

    王先科

    2015-01-01

    The novel Good Weather ofOne Person written by Japanese authoress Aoyama Nanae ,in a relaxed tone,shows us the loneliness and growth of young women’s under the metropolis background.The felling of fe-male’s solitude and self - growth in the novel inflects her particular awareness to feminism,i.e.the self discovery and self cognition of the women.Although the feminism awareness in the novel is hidden in the simple narration a-bout the daily life,it always leads the development of the stories and becomes the focus to attract and move the readers.%日本作家青山七惠的小说《一个人的好天气》以轻松的笔调呈现出大都市背景下年轻女性的孤独与成长。小说中女性独特的孤独心理和自我成长体现了作者特有的女性意识,即作为女性对自我的发现和认知。这一女性意识隐藏在对日常生活的平淡叙述中,但始终牵引着故事的发展,成为小说吸引和感染读者的关键所在。

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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)

  14. 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.

  15. Strength and Balance Exercises

    Science.gov (United States)

    ... close to a wall, chair or table for balance. Action: Shift your weight onto one leg. Stand on that foot and stretch the other leg out in front of you, a few inches off the floor. Stand on one leg for eight counts. For an extra workout, flex and point your lifted foot. That is, bend the ankle ...

  16. 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

  17. Ankle muscle activity modulation during single-leg stance differs between children, young adults and seniors.

    Science.gov (United States)

    Kurz, Eduard; Faude, Oliver; Roth, Ralf; Zahner, Lukas; Donath, Lars

    2018-02-01

    Incomplete maturation and aging-induced declines of the neuromuscular system affect postural control both in children and older adults and lead to high fall rates. Age-specific comparisons of the modulation of ankle muscle activation and behavioral center of pressure (COP) indices during upright stance have been rarely conducted. The objective of the present study was to quantify aging effects on a neuromuscular level. Thus, surface electromyography (SEMG) modulation and co-activity of ankle muscles during single-leg standing was compared in healthy children, young adults and seniors. Postural steadiness (velocity and mean sway frequency of COP), relative muscle activation (SEMG modulation) and co-activation of two ankle muscles (tibialis anterior, TA; soleus, SO) were examined during single-leg stance in 19 children [age, 9.7 (SD 0.5) years], 30 adults [23.3 (1.5) years] and 29 seniors [62.7 (6.1) years]. Velocity of COP in medio-lateral and anterior-posterior directions, mean sway frequency in anterior-posterior direction, relative muscle activation (TA and SO) and co-activation revealed large age effects (P  0.14). Post-hoc comparisons indicated higher COP velocities, anterior-posterior frequencies, relative SO activation and co-activation in children and seniors when compared with adults. Relative TA activation was higher in children and adults compared with seniors (P seniors seems to be counteracted with higher TA/SO co-activity and SO modulation. However, TA modulation is higher in children and adults, whereas seniors' TA modulation capacity is diminished. An aging-induced decline of TA motor units might account for deteriorations of TA modulation in seniors.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Determinant Factors of Technical-Tactical Combinations Frequency in standing position during Womens World Senior Championships 2009

    Directory of Open Access Journals (Sweden)

    David Eduardo López González

    2011-03-01

    Full Text Available Abstract Objective. To classify the perfomance  of world class women wrestlers as the frequency and characteristics of their Technical-Tactical Combinations (TTC with effectiveness in the standing position during the most important competition on the international calendar 2009.Methods.  In the TTC were characterized all standing position effectives by a sample of 70 wrestlers, occupants of the top 10 in each of the 7 weight categories convened. Descriptive variables were used 5 of effectiveness, technical group, and characteristics of its phases. Variables were obtained determining the effectiveness, measured the "success rate" achieved by each fighter, all through factor analysis. Later wrestlers were classified by cluster analysis by Ward's method.Results. The most important factor related to get a medal  was the execution of legs attacks of with several possible endings started with almost no contact with the opponent, followed by the use of low-risk attacks launched from a firm grip. The wrestlers opted mostly for defense and counter low risk. Most of the competitors who had good results using several and alternative projections also managed to end their attacks.Conclusions. Characterization Model used and the factors of effectiveness in the fight standing obtained provided detailed explanations of the performance characteristics of the best wrestlers in the Senior World Championships 2009. The design of this research can be applied year after year in both freestyle and women's.Key words: Technical - Tactical Combinations, Rules, Fighting Women, Factor Analysis and Effectiveness

  9. Determinant Factors of Technical-Tactical Combinations Frequency in standing position during Womens World Senior Championships 2009

    Directory of Open Access Journals (Sweden)

    David Eduardo López González

    2011-03-01

    Full Text Available Abstract  Objective. To classify the perfomance  of world class women wrestlers as the frequency and characteristics of their Technical-Tactical Combinations (TTC with effectiveness in the standing position during the most important competition on the international calendar 2009. Methods.  In the TTC were characterized all standing position effectives by a sample of 70 wrestlers, occupants of the top 10 in each of the 7 weight categories convened. Descriptive variables were used 5 of effectiveness, technical group, and characteristics of its phases. Variables were obtained determining the effectiveness, measured the "success rate" achieved by each fighter, all through factor analysis. Later wrestlers were classified by cluster analysis by Ward's method. Results. The most important factor related to get a medal  was the execution of legs attacks of with several possible endings started with almost no contact with the opponent, followed by the use of low-risk attacks launched from a firm grip. The wrestlers opted mostly for defense and counter low risk. Most of the competitors who had good results using several and alternative projections also managed to end their attacks. Conclusions. Characterization Model used and the factors of effectiveness in the fight standing obtained provided detailed explanations of the performance characteristics of the best wrestlers in the Senior World Championships 2009. The design of this research can be applied year after year in both freestyle and women's. Key words: Technical - Tactical Combinations, Rules, Fighting Women, Factor Analysis and Effectiveness

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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...

  12. [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.

  13. 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.

  14. 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.

  15. 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.

  16. 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'.

  17. 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.

  18. 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.

  19. 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)

  20. 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...

  1. Does Tibial Slope Affect Perception of Coronal Alignment on a Standing Anteroposterior Radiograph?

    Science.gov (United States)

    Schwartz, Adam J; Ravi, Bheeshma; Kransdorf, Mark J; Clarke, Henry D

    2017-07-01

    A standing anteroposterior (AP) radiograph is commonly used to evaluate coronal alignment following total knee arthroplasty (TKA). The impact of coronal alignment on TKA outcomes is controversial, perhaps due to variability in imaging and/or measurement technique. We sought to quantify the effect of image rotation and tibial slope on coronal alignment. Using a standard extramedullary tibial alignment guide, 3 cadaver legs were cut to accept a tibial tray at 0°, 3°, and 7° of slope. A computed tomography scan of the entire tibia was obtained for each specimen to confirm neutral coronal alignment. Images were then obtained at progressive 10° intervals of internal and external rotation up to 40° maximum in each direction. Images were then randomized and 5 blinded TKA surgeons were asked to determine coronal alignment. Continuous data values were transformed to categorical data (neutral [0], valgus [L], and varus [R]). Each 10° interval of external rotation of a 7° sloped tibial cut (or relative internal rotation of a tibial component viewed in the AP plane) resulted in perception of an additional 0.75° of varus. The slope of the proximal tibia bone cut should be taken into account when measuring coronal alignment on a standing AP radiograph. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. 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

  3. Unipedal standing exercise and hip bone mineral density in postmenopausal women: a randomized controlled trial.

    Science.gov (United States)

    Sakai, Akinori; Oshige, Toshihisa; Zenke, Yukichi; Yamanaka, Yoshiaki; Nagaishi, Hitoshi; Nakamura, Toshitaka

    2010-01-01

    The aim of this study was to test the effect of unipedal standing exercise on bone mineral density (BMD) of the hip in postmenopausal women. Japanese postmenopausal women (n = 94) were assigned at random to an exercise or control group (no exercise). The 6-month exercise program consisted of standing on a single foot for 1 min per leg 3 times per day. BMD of the hip was measured by dual-energy X-ray absorptiometry. There was no significant difference in age and baseline hip BMD between the exercise group (n = 49) and control group (n = 45). Exercise did not improve hip BMD compared with the control group. Stepwise regression analysis identified old age as a significant determinant (p = 0.034) of increased hip total BMD at 6 months after exercise. In 31 participants aged >/=70 years, the exercise group (n = 20) showed significant increase in the values of hip BMD at the areas of total (p = 0.008), intertrochanteric (p = 0.023), and Ward's triangle (p = 0.032). The same parameters were decreased in the control group (n = 11). The percent changes in hip BMD of the exercise group were not significantly different from those of the control group either in the participants with low baseline hip total BMD ( or =80% of the young adult mean). In conclusion, unipedal standing exercise for 6 months did not improve hip BMD in Japanese postmenopausal women. Effect of exercise on hip total BMD was age dependent. In participants aged > or =70 years, the exercise significantly increased hip total BMD.

  4. Spatially resolved observation of the fundamental and second harmonic standing kink modes using SDO/AIA

    Science.gov (United States)

    Pascoe, D. J.; Goddard, C. R.; Nakariakov, V. M.

    2016-09-01

    Aims: We consider a coronal loop kink oscillation observed by the Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) which demonstrates two strong spectral components. The period of the lower frequency component being approximately twice that of the shorter frequency component suggests the presence of harmonics. Methods: We examine the presence of two longitudinal harmonics by investigating the spatial dependence of the loop oscillation. The time-dependent displacement of the loop is measured at 15 locations along the loop axis. For each position the displacement is fitted as the sum of two damped sinusoids, having periods P1 and P2, and a damping time τ. The shorter period component exhibits anti-phase oscillations in the loop legs. Results: We interpret the observation in terms of the first (global or fundamental) and second longitudinal harmonics of the standing kink mode. The strong excitation of the second harmonic appears connected to the preceding coronal mass ejection (CME) which displaced one of the loop legs. The oscillation parameters found are P1 = 5.00±0.62 min, P2 = 2.20±0.23 min, P1/ 2P2 = 1.15±0.22, and τ/P = 3.35 ± 1.45. A movie associated to Fig. 5 is available in electronic form at http://www.aanda.org

  5. 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

  6. 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 ...

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies

    Science.gov (United States)

    Wayne, Peter M.; Gow, Brian J.; Costa, Madalena D.; Peng, C.-K.; Lipsitz, Lewis A.; Hausdorff, Jeffrey M.; Davis, Roger B.; Walsh, Jacquelyn N.; Lough, Matthew; Novak, Vera; Yeh, Gloria Y.; Ahn, Andrew C.; Macklin, Eric A.; Manor, Brad

    2014-01-01

    Background Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale “complexity” of postural sway fluctuations. Objectives To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults. Methods A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up–and-Go tests characterized physical function. Results At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (Padults. Trial Registration ClinicalTrials.gov NCT01340365 PMID:25494333

  12. 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.

  13. 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.

  14. 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)

  15. 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 ...

  16. 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.

  17. 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.

  18. 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...

  19. 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...

  20. 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.

  1. 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...

  2. 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...

  3. 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.

  4. The comparison of manual lymph drainage and ultrasound therapy on the leg swelling caused by wearing high heels.

    Science.gov (United States)

    Lee, Dong-Yeop; Han, Ji-Su; Jang, Eun-Ji; Seo, Dong-Kwon; Hong, Ji-Heon; Lee, Sang-Sook; Lee, Dong-Geol; Yu Lee, Jae-Ho

    2014-01-01

    One of the major symptoms when women are wearing high heels for a long time is leg swelling. The purpose of this study was to compare the effect of manual lymph drainage with ultrasound therapy. The forty-five healthy women of twenties were participated in this study and divided randomly into three groups; manual lymph drainage group (n=15), ultrasound therapy group (n=15) and control group (n=15). Swelling was measured before wearing the high heels (10 cm-height), after one-hour of wearing the high heels, wearing the high heels of one-hour after the intervention of 15 minutes. Also swelling was calculated by using a tape measure, volumeter and body composition analyzer. Statistical analysis of the comparison between the three groups was performed by one-way ANOVA. Also comparison to the mean value in swelling according to the time was performed by repeated measure ANOVA. As the result of this study, a significant changes have emerged within each of manual lymph drainage, ultrasound therapy and control group (p 0.05). But the mean value of manual lymph drainage group showed the tendency of fast recovering before causing swelling. Therefore, we consider that the clinical treatment of manual lymph drainage and ongoing studies will be made since manual lymph drainage is very effective in releasing the leg swelling caused by wearing high heels and standing for a long time at work.

  5. Diurnal variations in lower leg subcutaneous blood flow rate in patients with chronic venous leg ulcers

    DEFF Research Database (Denmark)

    Sindrup, J H; Kastrup, J; Kristensen, J K

    1991-01-01

    The blood flow rate in subcutaneous adipose tissue was measured on the lower legs of 11 patients with chronic lower-leg venous insufficiency and ulceration and in eight age-matched control subjects for 12-20 h, under ambulatory conditions, using the 133Xe wash-out technique with portable Cadmium...... telluride (CdTe(Cl)) detectors. In both groups, the change from an upright to a supine position at the beginning of the night period elicited an instantaneous increment in the blood flow rate of 30-40% with a decrease in the central and local postural sympathetic vasoconstrictor activity. After...... approximately 1 h of sleep, a considerable increase in blood flow rate was seen in both patient and control groups which persisted for nearly 100 min. In the patient group, the mean increase was 137% compared to a mean increase of 68% in the control group (P less than 0.01). The blood flow then returned...

  6. 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.

  7. Reineke’s stand density index: a quantitative and non-unitless measure of stand density

    Science.gov (United States)

    Curtis L. VanderSchaaf

    2013-01-01

    When used as a measure of relative density, Reineke’s stand density index (SDI) can be made unitless by relating the current SDI to a standard density but when used as a quantitative measure of stand density SDI is not unitless. Reineke’s SDI relates the current stand density to an equivalent number of trees per unit area in a stand with a quadratic mean diameter (Dq)...

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. The effect of a nurse-directed intervention to reduce pain and improve behavioral and physical outcomes in patients with critically colonized/infected chronic leg ulcers.

    Science.gov (United States)

    Kelechi, Teresa J; Mueller, Martina; Spencer, Cam; Rinard, Bobbie; Loftis, Greg

    2014-01-01

    ankle range of motion (P = .498). Functional and physical activity scores revealed no statistically significant differences in 3 measures, including Timed Up and Go test (P = .624), Timed Chair Standing Test (P = .686), or the Community Health Activities Model for Seniors (P = .803). While somewhat feasible to implement in the wound care setting, no improvement in outcomes was observed with the addition of the WOC nurse-directed intervention. However, pain in the lower legs of patients with critically colonized/infected wounds in both groups improved after a 6-week behavioral/physical activity intervention. A larger trial is needed to further elucidate these findings.

  13. 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.

  14. 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.

  15. 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)

  16. 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....

  17. 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.

  18. 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…

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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...

  6. 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...

  7. 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,

  8. 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...

  9. 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

  10. 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.

  11. 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

  12. Adaptation to altered balance conditions in unilateral amputees due to atherosclerosis: a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Bretz Éva

    2011-05-01

    Full Text Available Abstract Background Amputation impairs the ability to balance. We examined adaptation strategies in balance following dysvascularity-induced unilateral tibial amputation in skilled prosthetic users (SPU and first fitted amputees (FFA (N = 28. Methods Excursions of center of pressure (COP were determined during 20 s quiet standing using a stabilometry system with eyes-open on both legs or on the non-affected leg(s. Main measures: COP trajectories and time functions; distribution of reaction forces between the two legs; inclination angles obtained through second order regression analysis using stabilogram data. Results FFA vs SPU demonstrated 27.8% greater postural sway in bilateral stance (p = 0.0004. Postural sway area was smaller in FFA standing on the non-affected leg compared with SPU (p = 0.028. The slope of the regression line indicating postural stability was nearly identical in FFA and SPU and the direction of regression line was opposite for the left and right leg amputees. Conclusion Of the two adaptation strategies in balance, the first appears before amputation due to pain and fatigue in the affected leg. This strategy appears in the form of reduced postural sway while standing on the non-affected leg. The second adaptation occurs during rehabilitation and regular use of the prosthesis resulting in normal weightbearing associated with reduced postural sway on two legs and return to the normal postural stability on one leg.

  13. 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)

  14. 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.

  15. 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

  16. 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...

  17. 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...

  18. 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

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Learning to Stand: The Acceptability and Feasibility of Introducing Standing Desks into College Classrooms

    Directory of Open Access Journals (Sweden)

    Roberto M. Benzo

    2016-08-01

    Full Text Available Prolonged sedentary behavior is an independent risk factor for multiple negative health outcomes. Evidence supports introducing standing desks into K-12 classrooms and work settings to reduce sitting time, but no studies have been conducted in the college classroom environment. The present study explored the acceptability and feasibility of introducing standing desks in college classrooms. A total of 993 students and 149 instructors completed a single online needs assessment survey. This cross-sectional study was conducted during the fall semester of 2015 at a large Midwestern University. The large majority of students (95% reported they would prefer the option to stand in class. Most students (82.7% reported they currently sit during their entire class time. Most students (76.6% and instructors (86.6% reported being in favor of introducing standing desks into college classrooms. More than half of students and instructors predicted having access to standing desks in class would improve student’s “physical health”, “attention”, and “restlessness”. Collectively, these findings support the acceptability of introducing standing desks in college classrooms. Future research is needed to test the feasibility, cost-effectiveness and efficacy of introducing standing desks in college classrooms. Such studies would be useful for informing institutional policies regarding classroom designs.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. Analysis of the Relationship between Elite Wrestlers’ Leg Strength and Balance Performance, and Injury History

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. 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)

  17. 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.

  18. 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

  19. 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

  20. 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 ...

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. Multi-Purpose Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Multi-Purpose Test Stand is used for a wide variety of tests. The Stand is designed to be rotated through a range of fixed yaw positions to allow engines to be...

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. [Stabilometry, Electromyography and Electroencephalography in Postmenopausal Women after Training of the Leg Support Sensation].

    Science.gov (United States)

    Bazanova, O M; Kholodina, N V; Podoinikov, A S; Nikolenko, E D

    2015-01-01

    Ageing, lack of physical activity and sedentary lifestyle cause disorders of the sensorimotor system of postural control. The role of support afferentation in the changes in cortical activity in balance impairments has not been studied yet. The purpose of this study was to investigate the changes in the stabilographic parameters of the body center of gravity, alpha activity indices of the electroencephalography (EEG) and electromyographic (EMG) measurements of forehead muscle tone in response to visual activation in standing and sitting positions in postmenopausal women after and without training of leg support sensation (LSS) The variables were compared between 3 groups: Group A (n = 12, age: 66 ± 9 years)--women who have trained LSS with the help of Aikido techniques for 8 years; group F (n = 12, age: 65 ± 6 years)--women who have attended Fitness training for 8 years; group N (n = 11, age: 66 ± 7 years)--women who have not taken physical exercises for the last 8 years. It was found that in group N a change in body position from "sitting" to "standing" leads to a much greater increase in the area of stabilogram and in the energy expenditure needed to maintain the bal- ance than in groups A and F. Posture changes from sitting to standing position increases the tension of the forehead muscles and the suppression of alpha-1-amplitude, but decreases the power in high- and low-frequency alpha-band of EEG and the width of alpha-band in group N. In women ofgroup F the posture change does not result in an increase in EMG and signs of activation or tension in EEG; in group A it leads to a decrease of visual activation indices and psychoemotional tension and to an increase in power in alpha-2-band which is a sign of neuronal efficiency. Basing on these data, we can conclude that training focused on support afferentation in postmenopausal women decreases the psychoemotional tension and increases neuronal efficiency ofsensorimotor integration of postural control system

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Using a stand-level model to predict light absorption in stands with vertically and horizontally heterogeneous canopies

    Directory of Open Access Journals (Sweden)

    David I Forrester

    2014-09-01

    Full Text Available Background Forest ecosystem functioning is strongly influenced by the absorption of photosynthetically active radiation (APAR, and therefore, accurate predictions of APAR are critical for many process-based forest growth models. The Lambert-Beer law can be applied to estimate APAR for simple homogeneous canopies composed of one layer, one species, and no canopy gaps. However, the vertical and horizontal structure of forest canopies is rarely homogeneous. Detailed tree-level models can account for this heterogeneity but these often have high input and computational demands and work on finer temporal and spatial resolutions than required by stand-level growth models. The aim of this study was to test a stand-level light absorption model that can estimate APAR by individual species in mixed-species and multi-layered stands with any degree of canopy openness including open-grown trees to closed canopies. Methods The stand-level model was compared with a detailed tree-level model that has already been tested in mixed-species stands using empirical data. Both models were parameterised for five different forests, including a wide range of species compositions, species proportions, stand densities, crown architectures and canopy structures. Results The stand-level model performed well in all stands except in the stand where extinction coefficients were unusually variable and it appears unlikely that APAR could be predicted in such stands using (tree- or stand-level models that do not allow individuals of a given species to have different extinction coefficients, leaf-area density or analogous parameters. Conclusion This model is parameterised with species-specific information about extinction coefficients and mean crown length, diameter, height and leaf area. It could be used to examine light dynamics in complex canopies and in stand-level growth models.

  4. 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...

  5. 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

  6. 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

  7. 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

  8. Thinning in artificially regenerated young beech stands

    Directory of Open Access Journals (Sweden)

    Novák Jiří

    2015-12-01

    Full Text Available Although beech stands are usually regenerated naturally, an area of up to 5,000 ha year−1 is artificially regenerated by beech in the Czech Republic annually. Unfortunately, these stands often showed insufficient stand density and, consequently, lower quality of stems. Therefore, thinning methods developed for naturally regenerated beech stands are applicable with difficulties. The paper evaluates the data from two thinning experiments established in young artificially regenerated beech stands located in different growing conditions. In both experiments, thinning resulted in the lower amount of salvage cut in following years. Positive effect of thinning on periodic stand basal area increment and on periodic diameter increment of dominant trees was found in the beech stand located at middle elevations. On the other hand, thinning effects in mountain conditions were negligible. Thinning focusing on future stand quality cannot be commonly applied in artificially regenerated beech stands because of their worse initial quality and lower density. However, these stands show good growth and response to thinning, hence their management can be focused on maximising beech wood production.

  9. Comparison of conversion coefficients for equivalent dose in terms of air kerma using a sitting and standing female adult voxel simulators exposure to photons in antero-posterior irradiation geometry

    International Nuclear Information System (INIS)

    Cavalcante, F.R.; Galeano, D.C.; Carvalho Júnior, A.B.; Hunt, J.

    2014-01-01

    Due to the difficulty in implementing invasive techniques for calculations of dose for some exposure scenarios, computational simulators have been created to represent as realistically as possible the structures of the human body and through radiation transport simulations to obtain conversion coefficients (CCs) to estimate dose. In most published papers simulators are implemented in the standing posture and this may not describe a real scenario of exposure. In this work we developed exposure scenarios in the Visual Monte Carlo (VMC) code using a female simulator in standing and sitting postures. The simulator was irradiated in the antero-posterior (AP) geometry by a plane source of monoenergetic photons with energy from 10 keV to 2 MeV. The conversion coefficients for equivalent dose in terms of air kerma (H T /K air ) were calculated for both scenarios and compared. The results show that the percentage difference of CCs for the organs of the head and thorax was not significant (less than 5%) since the anatomic position of the organs is the same in both postures. The percentage difference is more significant to the ovaries (71% for photon energy of 20 keV), to the bladder (39% at 60 keV) and to the uterus (37% at 100 keV) due to different processes of radiation interactions in the legs of the simulator when its posture is changed. For organs and tissues that are distributed throughout the entire body, such as bone (21% at 100 keV) and muscle (30% at 80 keV) the percentage difference of CCs reflects a reduction of interaction of photons with the legs of the simulator. Therefore, the calculation of conversion coefficients using simulators in the sitting posture is relevant for a more accurate dose estimation in real exposures to radiation. - Highlights: ► Scenarios of external photon exposures were performed in VMC code. ► The FAX simulator was irradiated in sitting and standing postures. ► The irradiation geometry used was the antero-posterior (AP). ► The

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. 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,

  17. Refrigeration system having standing wave compressor

    Science.gov (United States)

    Lucas, Timothy S.

    1992-01-01

    A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

  18. Control of leg movements driven by EMG activity of shoulder muscles

    Directory of Open Access Journals (Sweden)

    Valentina eLa Scaleia

    2014-10-01

    Full Text Available During human walking there exists a functional neural coupling between arms and legs, and between cervical and lumbosacral pattern generators. Here we present a novel approach for associating the electromyographic (EMG activity from upper limb muscles with leg kinematics. Our methodology takes advantage of the high involvement of shoulder muscles in most locomotor-related movements and of the natural coordination between arms and legs. Nine healthy subjects were asked to walk at different constant and variable speeds (3-5 km/h, while EMG activity of shoulder (deltoid muscles and the kinematics of walking were recorded. To ensure a high level of EMG activity in deltoid, the subjects performed slightly larger arm swinging than they usually do. The temporal structure of the burst-like EMG activity was used to predict the spatiotemporal kinematic pattern of the forthcoming step. A comparison of actual and predicted stride leg kinematics showed a high degree of correspondence (r>0.9. This algorithm has been also implemented in pilot experiments for controlling avatar walking in a virtual reality setup and an exoskeleton during overground stepping. The proposed approach may have important implications for the design of human-machine interfaces and neuroprosthetic technologies such as those of assistive lower limb exoskeletons.

  19. Restless legs syndrome and impact on work performance

    Directory of Open Access Journals (Sweden)

    Diana Samara

    2016-02-01

    Full Text Available Restless legs syndrome (RLS is a neurological sensorimotor disorder characterized by unpleasant sensations in the legs and an uncontrollable urge to move them for relief. The RSL prevalence in the general population is 0.1% - 11.5%, and increases with age, with the highest effect of producing a primary sleep disorder (70%-80%. Women appear to be at increased risk, as do individuals with certain chronic conditions, including renal failure and anemia. The pathophysiology of RLS is incompletely understood, but it probably results from derangements in dopamine and iron metabolism, and has a genetic component. RSL could be idiopathic or secondary (usually related with iron deficiency, terminal renal failure, pregnancy, and spinal cord lesions. RLS patients usually have sleep disorders, so the disease can cause difficulties and problems in occupational and social life. Subjects with RLS symptoms appear to experience significantly more daytime problems, including being late for work, making errors at work, or missing work because of sleepiness. The diagnosis of RLS is made by following the criteria of the International Restless Legs Syndrome Study Group (IRLSSG. Pharmacologic RLS therapy, in which dopaminergic drugs constitute the first line, is effective and may have a dramatic effect on symptoms and quality of life. Identifying and treating RLS may improve sleep quality, daytime function and work performance.

  20. Restless legs syndrome and impact on work performance

    Directory of Open Access Journals (Sweden)

    Diana Samara

    2009-04-01

    Full Text Available Restless legs syndrome (RLS is a neurological sensorimotor disorder characterized by unpleasant sensations in the legs and an uncontrollable urge to move them for relief. The RSL prevalence in the general population is 0.1% - 11.5%, and increases with age, with the highest effect of producing a primary sleep disorder (70%-80%. Women appear to be at increased risk, as do individuals with certain chronic conditions, including renal failure and anemia. The pathophysiology of RLS is incompletely understood, but it probably results from derangements in dopamine and iron metabolism, and has a genetic component. RSL could be idiopathic or secondary (usually related with iron deficiency, terminal renal failure, pregnancy, and spinal cord lesions. RLS patients usually have sleep disorders, so the disease can cause difficulties and problems in occupational and social life. Subjects with RLS symptoms appear to experience significantly more daytime problems, including being late for work, making errors at work, or missing work because of sleepiness. The diagnosis of RLS is made by following the criteria of the International Restless Legs Syndrome Study Group (IRLSSG. Pharmacologic RLS therapy, in which dopaminergic drugs constitute the first line, is effective and may have a dramatic effect on symptoms and quality of life. Identifying and treating RLS may improve sleep quality, daytime function and work performance.

  1. 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.

  2. Spontaneous regression of primary diffuse large B-cell lymphoma, leg type.

    Science.gov (United States)

    Alcántara-González, J; González-García, C; Fernández-Guarino, M; Jaén-Olasolo, P

    2014-01-01

    Primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL LT) accounts for approximately 20% of all primary cutaneous B-cell lymphomas and tends to present as infiltrated nodules, tumors, and plaques on the legs in the elderly. Unlike other primary cutaneous large B-cell lymphomas, it has a poor prognosis and tends to require treatment with systemic chemotherapy. We present the case of an 82-year-old patient with a 1-year history of nodules and plaques on her right leg. Biopsy led to a diagnosis of PCLBCL LT and the lesions resolved without treatment within 1 month of the first visit. This is an atypical course of PCLBCL LT and we believe that it is the first such case to be reported in the literature. Copyright © 2012 Elsevier España, S.L. and AEDV. All rights reserved.

  3. Theory Analysis and Experiment Research of the Leg Mechanism for the Human-Carrying Walking Chair Robot

    Directory of Open Access Journals (Sweden)

    Lingfeng Sang

    2014-01-01

    Full Text Available For the high carrying capacity of the human-carrying walking chair robot, in this paper, 2-UPS+UP parallel mechanism is selected as the leg mechanism; then kinematics, workspace, control, and experiment of the leg mechanism are researched in detail. Firstly, design of the whole mechanism is described and degrees of freedom of the leg mechanism are analyzed. Second, the forward position, inverse position, and velocity of leg mechanism are studied. Third, based on the kinematics analysis and the structural constraints, the reachable workspace of 2-UPS+UP parallel mechanism is solved, and then the optimal motion workspace is searched in the reachable workspace by choosing the condition number as the evaluation index. Fourth, according to the theory analysis of the parallel leg mechanism, its control system is designed and the compound position control strategy is studied. Finally, in optimal motion workspace, the compound position control strategy is verified by using circular track with the radius 100 mm; the experiment results show that the leg mechanism moves smoothly and does not tremble obviously. Theory analysis and experiment research of the single leg mechanism provide a theoretical foundation for the control of the quadruped human-carrying walking chair robot.

  4. Sympathetic Vasoconstrictor Responsiveness of the Leg Vasculature During Experimental Endotoxemia and Hypoxia in Humans

    DEFF Research Database (Denmark)

    Brassard, Patrice; Zaar, Morten; Thaning, Pia

    2016-01-01

    . DESIGN: Prospective descriptive study. SETTING: Hospital research laboratory. SUBJECTS: Ten healthy young men (age [mean ± SD], 31 ± 8 yr; body weight, 83 ± 10 kg) participated in the study. INTERVENTIONS: Leg blood flow and mean arterial pressure were determined, whereas leg vascular conductance...... was calculated during 1) adenosine infusion (vasodilator control), 2) hypoxia (FIO2 = 10%), 3) endotoxemia, and 4) endotoxemia + hypoxia. Leg sympathetic vasoconstrictor responsiveness (reduction in leg vascular conductance) was evaluated by femoral artery tyramine infusion. MEASUREMENTS AND MAIN RESULTS......: Endotoxemia increased body temperature from 36.9 ± 0.4°C to 38.6 ± 0.5°C (p necrosis factor-α from 6 pg/mL (3-8 pg/mL) to 391 pg/mL (128-2258 pg/mL) (p

  5. DUST, Albedo Monte-Carlo Simulation of Neutron Streaming in Multi-legged Square Concrete Ducts

    International Nuclear Information System (INIS)

    1993-01-01

    1 - Description of program or function: DUST simulates the thermal neutron streaming through multi-legged square concrete ducts. 2 - Method of solution: DUST uses the albedo Monte Carlo method. The albedo data used are in the form of empirical formulae based on the measured doubly differential albedo data. Sampling of the reflected polar and azimuthal angles is done by the rejection method. Variance reduction devices such as Russian Roulette are used. 3 - Restrictions on the complexity of the problem: - The albedo data and the subroutines for sampling the reflected polar and azimuthal angles are specific for concrete ducts. The maximum number of legs (as specified by dimension statements) is 5 and the maximum number of dose points is 50. The dose points considered are only in the last leg of the multi-legged duct

  6. Epilepsy and restless legs syndrome.

    Science.gov (United States)

    Geyer, James D; Geyer, Emery E; Fetterman, Zachary; Carney, Paul R

    2017-03-01

    Restless legs syndrome (RLS) is a common neurological movement disorder occurring in approximately 10% of the general population. The prevalence of moderately severe RLS is 2.7% overall (3.7% for women and 1.7% for men). Epilepsy is also a common neurological disorder with significant associated morbidity and impact on quality of life. We evaluated the severity and frequency of primary RLS in patients with localization-related temporal lobe epilepsy (TLE) and investigated the role of prodromal RLS symptoms as a warning sign and lateralizing indicator. All epilepsy patients seen in the outpatient clinic were screened for movement disorders from 2005 to 2015. Ninety-eight consecutive patients with localization-related TLE (50 right TLE and 48 left TLE) who met inclusion criteria were seen in the outpatient clinic. The control group consisted of 50 individuals with no history or immediate family history of epilepsy. Each patient was evaluated with the International Restless Legs Study Group (IRLSSG) questionnaire, NIH RLS diagnostic criteria, ferritin level, and comprehensive sleep screening including polysomnography. Furthermore, patients with obstructive sleep apnea or a definite cause of secondary restless legs syndrome such as low serum ferritin or serum iron levels were also excluded from the study. There was a significant association between the type of epilepsy and whether or not patients had RLS χ 2 (1)=10.17, p<.01, using the χ 2 Goodness of Fit Test. Based on the odds ratio, the odds of patients having RLS were 4.60 times higher if they had right temporal epilepsy than if they had left temporal epilepsy, serving as a potential lateralizing indicator. A prodromal sensation of worsening RLS occurred in some patients providing the opportunity to intervene at an earlier stage in this subgroup. We identified frequent moderate to severe RLS in patients with epilepsy. The frequency of RLS was much more common than would typically be seen in patients of similar

  7. Venous leg ulcer management: single use negative pressure wound therapy.

    Science.gov (United States)

    Dowsett, Caroline; Grothier, Lorraine; Henderson, Valerie; Leak, Kathy; Milne, Jeanette; Davis, Lynn; Bielby, Alistair; Timmons, John

    2013-06-01

    A number of leg ulcer specialist/tissue viability specialists from across the UK were invited to evaluate PICO (Smith and Nephew, Hull) as a treatment for venous leg ulcers also in conjunction with a variety of compression bandages and garments. Patients across 5 sites had PICO applied in conjunction with compression therapy. This group of treating clinicians were then asked to give feedback on the outcome of the patients on whom they had used the new device. All feedback was recorded at a meeting and this was used to create a guideline for use.

  8. 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

  9. 78 FR 68909 - Agency Information Collection (Knee and Lower Leg Conditions Disability Benefits Questionnaire...

    Science.gov (United States)

    2013-11-15

    ... Lower Leg Conditions Disability Benefits Questionnaire) Under OMB Review AGENCY: Veterans Benefits... Questionnaire)'' in any correspondence. FOR FURTHER INFORMATION CONTACT: Crystal Rennie, Enterprise Records... Conditions Disability Benefits Questionnaire)''. SUPPLEMENTARY INFORMATION: Title: Knee and Lower Leg...

  10. [Etiological diagnosis of leg ulcers].

    Science.gov (United States)

    Debure, Clélia

    2010-09-20

    Etiological diagnosis of leg ulcers must be the first step of treatment, even if we know that veinous disease is often present. We can build a clinical decisional diagram, which helps us to understand and not forget the other causes of chronic wounds and choose some basic examination, like ultrasound and histological findings. This diagnosis helps to choose the right treatment in order to cure even the oldest venous ulcers. Educational programs should be improved to prevent recurrence.

  11. An automatic hinge system for leg orthoses

    NARCIS (Netherlands)

    Rietman, J. S.; Goudsmit, J.; Meulemans, D.; Halbertsma, J. P. K.; Geertzen, J. H. B.

    2004-01-01

    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, fitted

  12. Chronic leg ulcer caused by Mycobacterium immunogenum

    NARCIS (Netherlands)

    Loots, Miriam A. M.; de Jong, Menno D.; van Soolingen, Dick; Wetsteyn, José C. F. M.; Faber, William R.

    2005-01-01

    Rare tropical skin diseases are seen more frequently in Western countries because of the increased popularity of visiting tropical regions. A 55-year-old white man developed a painless leg ulcer after traveling in Guatemala and Belize. A mycobacterium was cultured from a biopsy specimen and was

  13. Restless Legs Symptoms and Pregnancy and Neonatal Outcomes.

    Science.gov (United States)

    Oyieng'o, D Onentia; Kirwa, Kipruto; Tong, Iris; Martin, Susan; Antonio Rojas-Suarez, José; Bourjeily, Ghada

    2016-02-01

    Restless legs syndrome (RLS) is a commonly occurring neurologic disorder that affects up to one third of women during pregnancy. RLS has been associated with increased sympathetic tone in the nonpregnant population. We examined whether a RLS surrogate is associated with a higher prevalence of pregnancy and neonatal outcomes. Data were analyzed from a cross-sectional survey of 1000 women interviewed soon after delivery by using an RLS surrogate question. Women were asked how frequently (0 = none, 1 = rarely [pregnancy. Clinical charts were reviewed to obtain relevant demographic and clinical data, including the presence of gestational hypertensive disorders and neonatal outcomes at birth. Subjects who "always" experienced RLS were compared with subjects experiencing symptoms less frequently or not at all with respect to prevalence of gestational hypertensive disorder. The mean ([SD]) age, prepregnancy body mass index (BMI), and BMI at delivery were 29.0 (6.1) years, 26.1 (6.2) kg/m(2), and 32.0 (6.3) kg/m(2), respectively. The overall prevalence of the RLS surrogate (jumpy or jerky leg movements) was 35.5% with the following distribution on a Likert scale: score 1 = 6.4%; score 2 = 10.2%; score 3 = 8.1%; and score 4 = 10.8%. Chronic hypertension was present in 2.1%, pregnancy-induced hypertension in 9.5%, and preeclampsia in 4.5% of respondents. Subjects who reported "always" having sensations of jumpy or jerky legs were more likely to have gestational hypertensive disorders compared with those who reported less frequent occurrence of the symptoms. Adjusted odds ratios were 3.74 (95% CI, 1.31-10.72; P = 0.014) for chronic hypertension; 1.26 (95% CI, 0.65-2.46; P = 0.487) for pregnancy-induced hypertension; and 2.15 (95% CI, 0.97-4.75; P = 0.060) for preeclampsia. There was a significant association between leg movement score and neonatal birth weight (coefficient, -149.5 g [95% CI, -276.9 to -22.5]; P = 0.005) and gestational age at birth (-0.7 week [95% CI, -1.1 to

  14. The Influence of Residual Stand Densities on Regeneration in Sugar Maple Stands

    Science.gov (United States)

    Carl H. Tubbs

    1968-01-01

    Studies of regeneration 2, 5, and 10 years after cutting mature and overmature sugar maple stands to several residual densities show that (1) sugar maple is still the predominant species under all stand densities (2) nearly all regeneration reaching larger size classes became established before cutting (3) heavier cuttings (30, 50, and 70 square feet) are more rapidly...

  15. VDLLA: A virtual daddy-long legs optimization

    Science.gov (United States)

    Yaakub, Abdul Razak; Ghathwan, Khalil I.

    2016-08-01

    Swarm intelligence is a strong optimization algorithm based on a biological behavior of insects or animals. The success of any optimization algorithm is depending on the balance between exploration and exploitation. In this paper, we present a new swarm intelligence algorithm, which is based on daddy long legs spider (VDLLA) as a new optimization algorithm with virtual behavior. In VDLLA, each agent (spider) has nine positions which represent the legs of spider and each position represent one solution. The proposed VDLLA is tested on four standard functions using average fitness, Medium fitness and standard deviation. The results of proposed VDLLA have been compared against Particle Swarm Optimization (PSO), Differential Evolution (DE) and Bat Inspired Algorithm (BA). Additionally, the T-Test has been conducted to show the significant deference between our proposed and other algorithms. VDLLA showed very promising results on benchmark test functions for unconstrained optimization problems and also significantly improved the original swarm algorithms.

  16. The Narrow Ridge Balance Test : A measure for one-leg lateral balance control

    NARCIS (Netherlands)

    Curtze, Carolin; Postema, Klaas; Akkermans, Hilda W.; Otten, Bert; Hof, At L.

    2010-01-01

    The assessment of balance capacity for people with widely different balance abilities is an important issue in clinical practice We propose the narrow ridge balance test as a sensitive tool to assess one-leg balance capacity In this test participants are asked to perform single-leg stance on ridges

  17. Planter unit test stand

    Science.gov (United States)

    A planter test stand was developed to evaluate individual row-crop metering units in early 2013. This test stand provided the ability to quantify actual seed metering in terms of population, seed spacing, skips, and multiples over a range of meter RPMs and vacuum pressures. Preliminary data has been...

  18. Self-Described Differences Between Legs in Ballet Dancers: Do They Relate to Postural Stability and Ground Reaction Force Measures?

    Science.gov (United States)

    Mertz, Laura; Docherty, Carrie

    2012-12-01

    Ballet technique classes are designed to train dancers symmetrically, but they may actually create a lateral bias. It is unknown whether dancers in general are functionally asymmetrical, or how an individual dancer's perceived imbalance between legs might manifest itself. The purpose of this study was to examine ballet dancers' lateral preference by analyzing their postural stability and ground reaction forces in fifth position when landing from dance-specific jumps. Thirty university ballet majors volunteered to participate in this study. The subjects wore their own ballet technique shoes and performed fundamental ballet jumps out of fifth position on a force plate. The force plate recorded center of pressure (COP) and ground reaction force (GRF) data. Each subject completed a laterality questionnaire that determined his or her preferred landing leg for ballet jumps, self-identified stronger leg, and self-identified leg with better balance. All statistical comparisons were made between the leg indicated on the laterality questionnaire and the other leg (i.e., if the dancer's response to a question was "left," the comparison was made with the left leg as the "preferred" leg and the right leg as the "non-preferred leg"). No significant differences were identified between the limbs in any of the analyses conducted (all statistical comparisons produced p values > 0.05). The results of this study indicate that a dancer's preferential use of one limb over the other has no bearing on GRFs or balance ability after landing jumps in ballet. Similarly, dancers' opinions of their leg characteristics (such as one leg being stronger than the other) seem not to correlate with the dancers' actual ability to absorb GRFs or to balance when landing from ballet jumps.

  19. 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.

  20. 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

  1. THE ROLE OF LEG AND TRUNK MUSCLES PROPRIOCEPTION ON STATIC AND DYNAMIC POSTURAL CONTROL

    Directory of Open Access Journals (Sweden)

    SEYED Hossein Hosseinimehr

    2010-04-01

    Full Text Available The proprioception information is a prerequisite for balance, body’s navigation system, and the movement coordinator. Due to changes between the angles of ankle, knee, and hip joints the aforementioned information are important in the coordination of the limbs and postural balance. The aim of this study was to investigate therole of leg and trunk muscles proprioception on static and dynamic postural control. Thirty males students of physical education and sport sciences (age =21.23 ± 2.95 years, height = 170.4 ± 5.1 cm, and weight = 70.7 ± 5.6 kg participated in this study volunteered. Vibration (100HZ was used to disturb of proprioception. Vibrationoperated on leg muscle (gasterocnemius and trunk muscles (erector spine muscle, at L1 level. Leg stance time and Star Excursion Balance Test were used for evaluation of static and dynamic postural control respectively.Subjects performed pre and post (with operated vibration leg stance time and star excursion balance test. Paired sample test used for investigation the effect of vibration on leg and trunk muscles in static and dynamic postural control. Result of this study showed in static postural control, there is no significant difference between pre and post test (operated vibration in leg and trunk muscles (p≤0.05. In contrast there is significant difference indynamic postural control between pre and post test in leg muscles in 8 directions of star excursion balance test (p≤0.05 while there is only significant difference in trunk muscle in antrolateral and lateral of star excursion balance test (p≤0.05. During physical training such conditions like fatigue and injury can disturbproprioceptions’ information. Thus, due to the importance of this information we recommend that coaches'additionally specific trainings any sport used specific exercises to enhance the proprioception information

  2. 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.

  3. 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.

  4. Application of force-length curve for determination of leg stiffness during a vertical jump.

    Science.gov (United States)

    Struzik, Artur; Zawadzki, Jerzy

    2016-01-01

    The aim of this study was to present the methodology for estimation of a leg stiffness during a countermovement jump. The question was asked whether leg stiffness in the countermovement and take-off phases are similar to each other as demonstrated in previous reports. It was also examined whether the stiffness in left lower limb is similar to the one in right lower limb. The research was conducted on 35 basketball players. Each participant performed three countermovement jumps with arm swing to the maximum height. Measurements employed a Kistlerforce plate and a BTS SMART system for motion analysis. Leg stiffness (understood as an inclination of the curve of ground reaction forces vs. length) was computed for these parts of countermovement and take-off phases where its value was relatively constant and F(Δl) relationship was similar to linear. Mean value (±SD) of total stiffness of both lower limbs in the countermovement phase was 7.1 ± 2.3 kN/m, whereas this value in the take-off phase was 7.5 ± 1 kN/m. No statistically significant differences were found between the leg stiffness in the countermovement and the take-off phases. No statistically significant differences were found during the comparison of the stiffness in the right and left lower limb. The calculation methodology allows us to estimate the value of leg stiffness based on the actual shape of F(Δl) curve rather than on extreme values of ΔF and Δl. Despite different tasks of the countermovement and the take-off phases, leg stiffness in these phases is very similar. Leg stiffness during a single vertical jump maintains a relatively constant value in the parts with a small value of acceleration.

  5. 24 CFR 206.37 - Credit standing.

    Science.gov (United States)

    2010-04-01

    ... CONVERSION MORTGAGE INSURANCE Eligibility; Endorsement Eligible Mortgagors § 206.37 Credit standing. Each mortgagor must have a general credit standing satisfactory to the Secretary. ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Credit standing. 206.37 Section 206...

  6. Three-dimensional instability of standing waves

    Science.gov (United States)

    Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

    2003-12-01

    We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

  7. ON THE MAGNETISM AND DYNAMICS OF PROMINENCE LEGS HOSTING TORNADOES

    International Nuclear Information System (INIS)

    Martínez González, M. J.; Ramos, A. Asensio; Arregui, I.; Collados, M.; Beck, C.; Rodríguez, J. de la Cruz

    2016-01-01

    Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show that the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves).

  8. ON THE MAGNETISM AND DYNAMICS OF PROMINENCE LEGS HOSTING TORNADOES

    Energy Technology Data Exchange (ETDEWEB)

    Martínez González, M. J.; Ramos, A. Asensio; Arregui, I.; Collados, M. [Instituto de Astrofísica de Canarias, Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Beck, C. [National Solar Observatory, Sacramento Peak P.O. Box 62, Sunspot, NM 88349 (United States); Rodríguez, J. de la Cruz [Institute for Solar Physics, Department of Astronomy, Stockholm University, Albanova University Center, SE-10691 Stockholm (Sweden)

    2016-07-10

    Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show that the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves).

  9. Frequency and predisposing factors of leg cramps in pregnancy: a prospective clinical trial

    Directory of Open Access Journals (Sweden)

    Sohrabvand F

    2009-12-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Leg cramp is the painful contraction of the muscles that often occurs at night. Pregnancy is the most common cause of muscle cramps that usually occur in the second trimester of pregnancy. Although the reasons of the spasms had not been determined, the imbalance between the absorption and elimination of serum electrolytes such as Ca, Mg and potassium and also insufficiency of some vitamins and probably the changes in activities of motor neurons of spinal cord, can be the source of these problems. The aim of this study was the evaluation of frequency and predisposing factors of leg cramps."n"nMethods: In a cross sectional descriptive analytic study, a group of 400 women in the third trimester of pregnancy were asked to record the symptoms of leg cramp. Their education level and job recorded and their total serum level of Ca and Mg was measured in the first visit. Exclusion criteria included systemic medical conditions such as thyroid disease, diabetes, osteoporosis and prenatal disorders such as gestational diabetes mellitus and preeclampsia and patient cooperation."n"nResults: In our study the prevalence of leg cramp was 54.75%. There was a statistically significant relationship between leg cramp and serum

  10. Isokinetic leg strength and power in elite handball players.

    Science.gov (United States)

    González-Ravé, José M; Juárez, Daniel; Rubio-Arias, Jacobo A; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier

    2014-06-28

    Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players.

  11. Isokinetic Leg Strength and Power in Elite Handball Players

    Science.gov (United States)

    González-Ravé, José M.; Juárez, Daniel; Rubio-Arias, Jacobo A.; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier

    2014-01-01

    Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players. PMID:25114749

  12. 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.

  13. 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.

  14. Diagnostic leg scanning for deep venous thrombosis in the recently heparinized patient

    International Nuclear Information System (INIS)

    Mant, M.J.; O'Brien, B.D.; Russell, D.B.

    1981-01-01

    Leg scanning with fibrinogen 125I, either alone on in combination with other procedures, has been proposed as an alternative to venography for diagnosis of deep venous thrombi. Clinical circumstances may necessitate anticoagulation before scanning can be performed, which could alter its reliability. We have compared the results of scanning with venographic findings in heparinized patients with venous thromboembolism. Different criteria for an abnormal leg scan gave different sensitivities and specificities. During the first four days of scanning with a requirement for a persistently abnormal result, five of eight criteria had high specificity (greater than 92%). However, sensitivities did not exceed 55%. With the use of transiently abnormal results and six days of scanning, higher sensitivities were obtained but specificities were reduced. No criterion gave results considered acceptable for a diagnostic test for deep venous thrombosis. Leg scanning should therefore not be used for this purpose in patients who have received anticoagulants. Our results also suggest that duration of symptoms has little effect on the sensitivity of leg scanning and that the test is more reliable for establishing the presence of thrombus than at defining its location

  15. Unilateral pitting edema of the leg as a manifestation of Graves’ disease: a case report

    Directory of Open Access Journals (Sweden)

    Volke Vallo

    2012-08-01

    Full Text Available Abstract Introduction Graves’ hyperthyroidism has a number of well-recognized but relatively rare extrathyroid manifestations such as thyroid acropachy, pretibial myxedema, and congestive heart failure. Case presentation A 38-year-old Caucasian woman presented to the out-patient clinic with symptoms of hyperthyroidism lasting for approximately five months. Remarkably, she had developed pitting edema of her left leg four months before. She had gone through a conventional assessment, but the reason for the edema was not revealed. At presentation to the endocrinology clinic, the skin of both legs was of normal color and pitting edema on her left leg was of a diffuse nature and spread from her toes to two thirds of her leg. The skin surface of her left leg was smooth and had no elevations or discoloration, whereas her right leg appeared normal. Based on signs and symptoms of thyrotoxicosis and suppressed thyroid-stimulating hormone level (less than 0.001mIU/L, local reference of 0.4 to 4, treatment of 10mg of thiamazole three times a day was started. Additional blood tests revealed marked Graves’ hyperthyroidism with elevated free T4 and anti-thyroid receptor antibodies. Within a month, the free T4 level was normalized and the edema was completely cleared and never reappeared during the treatment course of 12 months. Conclusions To the best of our knowledge, this is the first description of unilateral treatment-responsive leg edema as a manifestation of Graves’ hyperthyroidism. However, the pathophysiological mechanism underlying this case of edema remains unclear.

  16. The role of arterial vascularity in pathogenesis of infected pseudoarthrosis of the lower leg

    International Nuclear Information System (INIS)

    Konarski, K.

    1993-01-01

    A series of 250 femoral arteriographies performed in patients with leg pseudoarthrosis served to asses condition of arteries of the extremity. It was found that vascular injuries contribute significantly to pathogenesis of union disorders in lower leg fractures. (author)

  17. Delineation of calf deep veins using 2D-TOF MR venography without contrast media. Efficacy of tourniquet and leg-warming

    International Nuclear Information System (INIS)

    Nagayoshi, Kensuke; Okada, Munemasa; Monzen, Yoshio; Kimura, Shojiro; Hamanaka, Yoshiharu; Ochi, Makoto; Hayashi, Kuniaki.

    1997-01-01

    We evaluated the imaging quality of 2D-TOF MR venography of the lower part of the leg and the efficacy of a tourniquet around the knee and leg-warming. In 8 healthy volunteers, MR venography was carried out under the following four conditions: usual MR venography, MR venography with tourniquet around the knee, MR venography after leg-warming and MR venography with tourniquet after leg-warming. Our results suggested that MR venography with tourniquet after leg-warming is best suited for imaging the veins of the leg. We also compared the diagnostic image quality of MR venography and conventional contrast venography in 7 patients with varices. The results showed no significant differences between the two methods. We conclude that MR venography with tourniquet after leg-warming is a technique that provides reliable information about the veins of the leg. (author)

  18. Acoustic radiation force on a sphere in standing and quasi-standing zero-order Bessel beam tweezers

    International Nuclear Information System (INIS)

    Mitri, F.G.

    2008-01-01

    Starting from the exact acoustic scattering from a sphere immersed in an ideal fluid and centered along the propagation axis of a standing or quasi-standing zero-order Bessel beam, explicit partial-wave representations for the radiation force are derived. A standing or a quasi-standing acoustic field is the result of propagating two equal or unequal amplitude zero-order Bessel beams, respectively, along the same axis but in opposite sense. The Bessel beam is characterized by the half-cone angle β of its plane wave components, such that β = 0 represents a plane wave. It is assumed here that the half-cone angle β for each of the counter-propagating acoustic Bessel beams is equal. Fluid, elastic and viscoelastic spheres immersed in water are treated as examples. Results indicate the capability of manipulating spherical targets based on their mechanical and acoustical properties. This condition provides an impetus for further designing acoustic tweezers operating with standing or quasi-standing Bessel acoustic waves. Potential applications include particle manipulation in micro-fluidic lab-on-chips as well as in reduced gravity environments

  19. Circadian variation of the effects of immobility on symptoms of restless legs syndrome.

    Science.gov (United States)

    Michaud, Martin; Dumont, Marie; Paquet, Jean; Desautels, Alex; Fantini, Maria Livia; Montplaisir, Jacques

    2005-07-01

    It is now well established that symptoms of restless legs syndrome (RLS) are worsened by immobility and that their severity fluctuates according to a circadian pattern with a maximum occurring in the late evening or during the night. However, no study has ever attempted to dissociate these two effects. The objective of this study was to evaluate the nycthemeral variations in the effects of duration of immobility on symptoms of RLS. A 28-hour modified constant routine protocol. Sleep Disorders Center, Montreal Sacré-Coeur Hospital. Seven patients with primary RLS (3 men, 4 women; mean age: 43.9 years) and seven controls matched for age (42.4 years) and gender. None. A 40-minute Suggested Immobilization Test (SIT) was repeated every 2 hours during the 28-hour protocol in order to quantify both subjective leg discomfort and periodic leg movements (PLM). Regarding leg discomfort, a two-way ANOVA performed on patients' data revealed a significant interaction (p = 0.037) between Time within the SIT and Time of day. Simple effect analyses performed to decompose the interaction showed that the increase in leg discomfort with duration of immobility was found only on SIT 7, 8, 9, 10 and 12, which corresponds to the period between 21:20 and 08:00. In addition, in patients, a significant circadian variation (p immobility is closely linked to their intrinsic circadian variation.

  20. Epidemiology, etiology, and treatment of chronic leg ulcer ...

    African Journals Online (AJOL)

    Background: Chronic leg ulcer (CLU) is reported to have an impact on virtually all ... Conclusion: Most patients benefited from debridement with or without split thickness skin graft or flap. .... low incidence of arterial and venous diseases in.

  1. Gabapentin enacarbil – clinical efficacy in restless legs syndrome

    Directory of Open Access Journals (Sweden)

    Pinky Agarwal

    2010-04-01

    Full Text Available Pinky Agarwal1, Alida Griffith1, Henry R Costantino2, Narendra Vaish31Booth Gardner Parkinson’s Center, Kirkland, WA, USA; 2Costantino Consulting, Woodinville, WA, USA; 3Kirkland, WA, USAAbstract: Restless legs syndrome (RLS is a sleep-related movement disorder commonly involving an unpleasant urge to move the limbs, typically the legs. Dopaminergic agents represent the first-line therapy for RLS; however, long-term use of such drugs results in worsening symptoms due to “augmentation” or other adverse events. Gabapentin, an analog of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA, is an anticonvulsant/analgesic agent. Gabapentin is only mildly effective in relieving RLS symptoms, perhaps a result of its poor absorption from the gastrointestinal (GI tract. Gabapentin enacarbil is a prodrug of gabapentin specifically designed to enhance absorption via the GI tract, and hence provide improved circulating levels of gabapentin on metabolism. Clinical trials to date have demonstrated favorable safety and (compared to traditional gabapentin improved pharmacokinetics and efficacy in treating RLS symptoms. Thus, gabapentin enacarbil may prove to be a useful drug in treating RLS. An application of gabapentin enacarbil for treatment of RLS is currently pending with FDA for approval.Keywords: restless legs syndrome, gabapentin enacarbil, movement disorder

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

    NARCIS (Netherlands)

    Heinen, M.M.; Bartholomew, L.K.; Wensing, M.J.P.; Kerkhof, P.C.M. van de; Achterberg, T. van

    2006-01-01

    OBJECTIVES: The objective of our project was to develop a lifestyle program for leg ulcer patients at outpatient clinics for dermatology. METHODS: We used the intervention-mapping (IM) framework for systematically developing theory and evidence based health promotion programs. We started with a

  3. How Can I Relieve My Pregnancy Leg Cramps?

    Science.gov (United States)

    ... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español How Can I Relieve My Pregnancy Leg Cramps? KidsHealth / For Parents / How Can I ...

  4. Report of a man with heterotopic ossification of the legs.

    Science.gov (United States)

    García-Arpa, Mónica; Flores-Terry, Miguel A; Franco-Muñoz, Monserrat; Villasanti-Rivas, Natalia; González-Ruiz, Lucía; Banegas-Illescas, M Eugenia

    2018-05-21

    Heterotopic ossification is an uncommon disorder that consists of deposition of ectopic bone outside the extraskeletal tissues. In the skin, it can be primary, in association with genetic syndromes, or be secondary to different disorders. The latter include subcutaneous ossification of the legs in chronic venousinsufficiency, an infrequent and unrecognized complication. We report the case of a patient with subcutaneous ossification of both legs secondary to venous insufficiency and review the literature. Copyright © 2018 Sociedad Española de Reumatologña y Colegio Mexicano de Reumatologña. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Painful swollen leg – think beyond deep vein thrombosis or Baker's cyst

    Directory of Open Access Journals (Sweden)

    Babu Vinayagam

    2008-01-01

    Full Text Available Abstract Background The diagnosis of deep vein thrombosis of leg is very common in clinical practice. Not infrequently a range of pathologies are diagnosed after excluding a thrombosis, often after a period of anticoagulation. Case presentation This is a report of three patients who presented with a painful swollen leg and were initially treated as a deep vein thrombosis or a baker's cyst, but later diagnosed as a pleomorphic sarcoma, a malignant giant cell tumor of the muscle and a myxoid liposarcoma. A brief review of such similar reports and the relevant literature is presented. Conclusion A painful swollen leg is a common clinical scenario and though rare, tumors must be thought of without any delay, in a duplex negative, low risk deep vein thrombosis situation.

  6. BUILDING A BETTER GLUTEAL BRIDGE: ELECTROMYOGRAPHIC ANALYSIS OF HIP MUSCLE ACTIVITY DURING MODIFIED SINGLE-LEG BRIDGES.

    Science.gov (United States)

    Lehecka, B J; Edwards, Michael; Haverkamp, Ryan; Martin, Lani; Porter, Kambry; Thach, Kailey; Sack, Richard J; Hakansson, Nils A

    2017-08-01

    Gluteal strength plays a role in injury prevention, normal gait patterns, eliminating pain, and enhancing athletic performance. Research shows high gluteal muscle activity during a single-leg bridge compared to other gluteal strengthening exercises; however, prior studies have primarily measured muscle activity with the active lower extremity starting in 90 ° of knee flexion with an extended contralateral knee. This standard position has caused reports of hamstring cramping, which may impede optimal gluteal strengthening. The purpose of this study was to determine which modified position for the single-leg bridge is best for preferentially activating the gluteus maximus and medius. Cross-Sectional. Twenty-eight healthy males and females aged 18-30 years were tested in five different, randomized single-leg bridge positions. Electromyography (EMG) electrodes were placed on subjects' gluteus maximus, gluteus medius, rectus femoris, and biceps femoris of their bridge leg (i.e., dominant or kicking leg), as well as the rectus femoris of their contralateral leg. Subjects performed a maximal voluntary isometric contraction (MVIC) for each tested muscle prior to performing five different bridge positions in randomized order. All bridge EMG data were normalized to the corresponding muscle MVIC data. A modified bridge position with the knee of the bridge leg flexed to 135 ° versus the traditional 90 ° of knee flexion demonstrated preferential activation of the gluteus maximus and gluteus medius compared to the traditional single-leg bridge. Hamstring activation significantly decreased (p bridge by flexing the active knee to 135 ° instead of 90 ° minimizes hamstring activity while maintaining high levels of gluteal activation, effectively building a bridge better suited for preferential gluteal activation. 3.

  7. A Study on Temperature Distribution in the Hot Leg Pipes considering the Variation of Flow Rate in RCS

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyuksu; Yi, Kunwoo; Choe, Yoonjae; Jang, Hocheol; Yune, Seokjeong; Park, Seongchan [KEPCO Engineering and Construction, Daejeon (Korea, Republic of)

    2016-10-15

    In this study, a computational analysis is performed to predict the deviation in the temperature distribution in the hot leg pipe according to the flow rate variation in RCS. In the hot leg pipes of Reactor Coolant System (RCS) of APR1400, four Resistance Temperature Detectors (RTDs), to obtain the average hot leg temperature, are installed at each hot leg pipe (two in the upper region and the other two in the lower region around the wall of the hot leg pipe). There is a deviation in temperature distribution in the hot leg pipe due to the sudden changes in the flow direction and area from the reactor core exit to the hot leg pipe. The non-uniform temperature distribution in the hot leg pipe can affect the measurement of the plant parameters such as the reactor power and the reactor coolant flow rate. The following conclusions are reached 1) The non-uniform temperature distribution in the core exit is sustained to some extent through the entire region of hot leg pipe. 2) The temperature ranges having a uniform pattern are 45 - 120° and 240 - 315°. The sensor positions of RTDs are located in this interval (45 - 120° and 240 - 315°) and this sensor positions of RTDs show the appropriate temperature measurement. Also, the temperature distribution shows the similar pattern without reference to the flow rate variation in RCS.

  8. Impact of restless legs syndrome in patients with inflammatory bowel disease on sleep, fatigue, and quality of life.

    Science.gov (United States)

    Schindlbeck, Katharina A; Becker, Janek; Berger, Felix; Mehl, Arne; Rewitzer, Charlotte; Geffe, Sarah; Koch, Peter M; Preiß, Jan C; Siegmund, Britta; Maul, Jochen; Marzinzik, Frank

    2017-01-01

    Inflammatory bowel disease has been associated with neurological symptoms including restless legs syndrome. Here, we investigated the impact of restless legs syndrome in patients with inflammatory bowel disease on sleep, fatigue, mood, cognition, and quality of life. Two groups of inflammatory bowel disease patients, with and without restless legs syndrome, were prospectively evaluated for sleep disorders, fatigue, daytime sleepiness, depression, anxiety, and health-related quality of life. Furthermore, global cognitive function, executive function, attention, and concentration were assessed in both groups. Disease activity and duration of inflammatory bowel disease as well as current medication were assessed by interview. Inflammatory bowel disease patients with and without restless legs syndrome were matched for age, education, severity, and duration of their inflammatory bowel disease. Patients with inflammatory bowel disease and clinically relevant restless leg syndrome suffered significantly more frequent from sleep disturbances including sleep latency and duration, more fatigue, and worse health-related quality of life as compared to inflammatory bowel disease patients without restless legs syndrome. Affect and cognitive function including cognitive flexibility, attention, and concentration showed no significant differences among groups, indicating to be not related to restless legs syndrome. Sleep disorders including longer sleep latency, shorter sleep duration, and fatigue are characteristic symptoms of restless legs syndrome in inflammatory bowel disease patients, resulting in worse health-related quality of life. Therefore, clinicians treating patients with inflammatory bowel disease should be alert for restless legs syndrome.

  9. 78 FR 38098 - Proposed Information Collection (Knee and Lower Leg Disability Benefits Questionnaire) Activity...

    Science.gov (United States)

    2013-06-25

    ... Control Number: 2900-NEW (Knee and Lower Leg Conditions Disability Benefits Questionnaire). Type of Review... and Lower Leg Disability Benefits Questionnaire) Activity: Comment Request AGENCY: Veterans Benefits... solicits comments on information needed to adjudicate the claim for VA disability benefits related to a...

  10. Hip proprioceptors preferentially modulate reflexes of the leg in human spinal cord injury

    Science.gov (United States)

    Onushko, Tanya; Hyngstrom, Allison

    2013-01-01

    Stretch-sensitive afferent feedback from hip muscles has been shown to trigger long-lasting, multijoint reflex responses in people with chronic spinal cord injury (SCI). These reflexes could have important implications for control of leg movements during functional activities, such as walking. Because the control of leg movement relies on reflex regulation at all joints of the limb, we sought to determine whether stretch of hip muscles modulates reflex activity at the knee and ankle and, conversely, whether knee and ankle stretch afferents affect hip-triggered reflexes. A custom-built servomotor apparatus was used to stretch the hip muscles in nine chronic SCI subjects by oscillating the legs about the hip joint bilaterally from 10° of extension to 40° flexion. To test whether stretch-related feedback from the knee or ankle would be affected by hip movement, patellar tendon percussions and Achilles tendon vibration were delivered when the hip was either extending or flexing. Surface electromyograms (EMGs) and joint torques were recorded from both legs. Patellar tendon percussions and Achilles tendon vibration both elicited reflex responses local to the knee or ankle, respectively, and did not influence reflex responses observed at the hip. Rather, the movement direction of the hip modulated the reflex responses local to the joint. The patellar tendon reflex amplitude was larger when the perturbation was delivered during hip extension compared with hip flexion. The response to Achilles vibration was modulated by hip movement, with an increased tonic component during hip flexion compared with extension. These results demonstrate that hip-mediated sensory signals modulate activity in distal muscles of the leg and appear to play a unique role in modulation of spastic muscle activity throughout the leg in SCI. PMID:23615544

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

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2017-02-01

    Full Text Available 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 cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

  12. Management of venous leg ulcers in general practice - a practical guideline.

    Science.gov (United States)

    Sinha, Sankar; Sreedharan, Sadhishaan

    2014-09-01

    Chronic venous leg ulcers are the most common wounds seen in general practice. Their management can be both challenging and time-consuming. To produce a short practical guideline incorporating the TIME concept and A2BC2D approach to help general practitioners and their practice nurses in delivering evidence-based initial care to patients with chronic venous leg ulcers. Most chronic venous leg ulcers can be managed effectively in the general practice setting by following the simple, evidence-based approach described in this article. Figure 1 provides a flow chart to aid in this process. Figure 2 illustrates the principles of management in general practice. Effective management of chronic ulcers involves the assessment of both the ulcer and the patient. The essential requirements of management are to debride the ulcer with appropriate precautions, choose dressings that maintain adequate moisture balance, apply graduated compression bandage after evaluation of the arterial circulation and address the patient's concerns, such as pain and offensive wound discharge.

  13. May 2015 critical care case of the month: an infected leg

    Directory of Open Access Journals (Sweden)

    Till SL

    2015-05-01

    Full Text Available No abstract available. Article truncated at 150 words. History of Present Illness: A 46-year-old transferred due to concern for necrotizing fasciitis. One the day prior to transfer purple discoloration was not noted in the lower portion of the left leg. On the day of transfer the leg became more purple, painful, and swollen. She presented to a pain clinic that advised her to go to an emergency room. The emergency room performed arterial Doppler ultrasound, which was normal and transferred her due to concern of necrotizing fasciitis. Past Medical History, Social History and Family History: She has a past medical history of fibromyalgia. She had an extensive surgical history including an appendectomy, bladder implant, cholecystectomy, dilatation and curettage, esophageal repair, left femoral artery repair due to a motor vehicle accident, partial hysterectomy, left knee surgery, and several left leg operations with grafting. Family history was non-contributory. The patient was single with two children, and smoked 1-2 packs of ...

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

    OpenAIRE

    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, ...

  15. Dynamics of underwater legged locomotion: modeling and experiments on an octopus-inspired robot.

    Science.gov (United States)

    Calisti, M; Corucci, F; Arienti, A; Laschi, C

    2015-07-30

    This paper studies underwater legged locomotion (ULL) by means of a robotic octopus-inspired prototype and its associated model. Two different types of propulsive actions are embedded into the robot model: reaction forces due to leg contact with the ground and hydrodynamic forces such as the drag arising from the sculling motion of the legs. Dynamic parameters of the model are estimated by means of evolutionary techniques and subsequently the model is exploited to highlight some distinctive features of ULL. Specifically, the separation between the center of buoyancy (CoB)/center of mass and density affect the stability and speed of the robot, whereas the sculling movements contribute to propelling the robot even when its legs are detached from the ground. The relevance of these effects is demonstrated through robotic experiments and model simulations; moreover, by slightly changing the position of the CoB in the presence of the same feed-forward activation, a number of different behaviors (i.e. forward and backward locomotion at different speeds) are achieved.

  16. LEGS data acquisition facility

    International Nuclear Information System (INIS)

    LeVine, M.J.

    1985-01-01

    The data acquisition facility for the LEGS medium energy photonuclear beam line is composed of an auxiliary crate controller (ACC) acting as a front-end processor, loosely coupled to a time-sharing host computer based on a UNIX-like environment. The ACC services all real-time demands in the CAMAC crate: it responds to LAMs generated by data acquisition modules, to keyboard commands, and it refreshes the graphics display at frequent intervals. The host processor is needed only for printing histograms and recording event buffers on magnetic tape. The host also provides the environment for software development. The CAMAC crate is interfaced by a VERSAbus CAMAC branch driver

  17. Comparative study of quality of life and psychosocial characteristics in patients with psoriasis and leg ulcers.

    Science.gov (United States)

    Kouris, Anargyros; Christodoulou, Christos; Efstathiou, Vasiliki; Tsatovidou, Revekka; Torlidi-Kordera, Evangelia; Zouridaki, Eftychia; Kontochristopoulos, George

    2016-03-01

    Psoriasis and leg ulcers have a marked impact on the patient's quality of life and represent a life-long burden for affected patients. The aim of this study is to compare the quality of life, anxiety and depression, self-esteem, and loneliness in patients with psoriasis and leg-ulcer patients. Eighty patients with leg ulcers, eighty patients with psoriasis, and eighty healthy controls were included in this study. The quality of life, depression and anxiety, loneliness of the patient, and self-esteem were assessed using the Dermatology Life Quality Index (DLQI), Hospital Anxiety and Depression Scale (HADS), the UCLA loneliness Scale (UCLA-Version 3), and the Rosenberg's Self-esteem Scale (RSES), respectively. The DLQI score among patients with psoriasis was 12.74 ± 4.89 and leg ulcer patients was 13.28 ± 2.57. The patients with psoriasis presented statistically significant higher anxiety (9.87 ± 4.56) than both leg ulcer patients (8.26 ± 2.82) and controls (6.45 ± 1.89), while leg ulcer patients also presented higher anxiety than controls. Regarding self-esteem, although there were no significant differences between the patients with psoriasis (15.25 ± 3.20) and the ones with leg ulcers (15.89 ± 2.93), they both presented statistically significant lower self-esteem scores than control group (18.53 ± 3.04). The patients with psoriasis presented statistically significant higher levels of loneliness and social isolation (46.18 ± 6.63) compared to leg ulcer patients (43.73 ± 5.68) than controls (42.49 ± 3.41). Psoriasis and leg ulcers are long-term skin diseases associated with significant impairment of the patient's quality of life, anxiety, and self-esteem, which are frequently under-recognized. © 2016 by the Wound Healing Society.

  18. Cold-Leg Small Break LOCA Analysis of APR1400 Plant Using a SPACE/sEM Code

    International Nuclear Information System (INIS)

    Lim, Sang Gyu; Lee, Suk Ho; Yu, Keuk Jong; Kim, Han Gon; Lee, Jae Yong

    2013-01-01

    The Small Break Loss-of-Coolant Accident (SBLOCA) evaluation methodology (EM) for APR1400, called sEM, is now being developed using SPACE code. SPACE/sEM is to set up a conservative evaluation methodology in accordance with appendix K of 10 CFR 50. Major required and acceptable features of the evaluation models are described as below. - Fission product decay : 1.2 times of ANS97 decay curve - Critical flow model : Henry-Fauske Moody two phase critical flow model - Metal-Water reaction model : Baker-Just equation - Critical Heat Flux (CHF) : B and W, Barnett and Modified Barnett correlation - Post-CHF : Groeneveld 5.7 film boiling correlation A series of test matrix is established to validate SPACE/sEM code in terms of major SBLOCA phenomena, e.g. core level swelling and boiling, core heat transfer, critical flow, loop seal clearance and their integrated effects. The separated effect tests (SETs) and integrated effect tests (IETs) are successfully performed and these results shows that SPACE/sEM code has a conservatism comparing with experimental data. Finally, plant calculations of SBLOCA for APR1400 are conducted as described below. - Break location sensitivity : DVI line, hot-leg, cold-leg, pump suction leg. - Break size spectrum : 0.4ft 2 ∼0.02ft 2 (DVI) 0.5ft 2 ∼0.02ft 2 (hot-leg, cold-leg, pump suction leg) This paper deals with break size spectrum analysis of cold-leg break accidents. Based on the calculation results, emergency core cooling system (ECCS) performances of APR1400 and typical SBLOCA phenomena can be evaluated. Cold-leg SBLOCA analysis for APR1400 is performed using SPACE/sEM code under harsh environment condition. SPACE/sEM code shows the typical SBLOCA behaviors and it is reasonably predicted. Although SPACE/sEM code has conservative models and correlations based on appendix K of 10 CFR 50, PCT does not exceed the requirement (1477 K). It is concluded that ECCS in APR1400 has a sufficient performance in cold-leg SBLOCA

  19. Cold-Leg Small Break LOCA Analysis of APR1400 Plant Using a SPACE/sEM Code

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Gyu; Lee, Suk Ho; Yu, Keuk Jong; Kim, Han Gon; Lee, Jae Yong [Central Research Institute, KHNP, Ltd., Daejeon (Korea, Republic of)

    2013-10-15

    The Small Break Loss-of-Coolant Accident (SBLOCA) evaluation methodology (EM) for APR1400, called sEM, is now being developed using SPACE code. SPACE/sEM is to set up a conservative evaluation methodology in accordance with appendix K of 10 CFR 50. Major required and acceptable features of the evaluation models are described as below. - Fission product decay : 1.2 times of ANS97 decay curve - Critical flow model : Henry-Fauske Moody two phase critical flow model - Metal-Water reaction model : Baker-Just equation - Critical Heat Flux (CHF) : B and W, Barnett and Modified Barnett correlation - Post-CHF : Groeneveld 5.7 film boiling correlation A series of test matrix is established to validate SPACE/sEM code in terms of major SBLOCA phenomena, e.g. core level swelling and boiling, core heat transfer, critical flow, loop seal clearance and their integrated effects. The separated effect tests (SETs) and integrated effect tests (IETs) are successfully performed and these results shows that SPACE/sEM code has a conservatism comparing with experimental data. Finally, plant calculations of SBLOCA for APR1400 are conducted as described below. - Break location sensitivity : DVI line, hot-leg, cold-leg, pump suction leg. - Break size spectrum : 0.4ft{sup 2}∼0.02ft{sup 2}(DVI) 0.5ft{sup 2}∼0.02ft{sup 2}(hot-leg, cold-leg, pump suction leg) This paper deals with break size spectrum analysis of cold-leg break accidents. Based on the calculation results, emergency core cooling system (ECCS) performances of APR1400 and typical SBLOCA phenomena can be evaluated. Cold-leg SBLOCA analysis for APR1400 is performed using SPACE/sEM code under harsh environment condition. SPACE/sEM code shows the typical SBLOCA behaviors and it is reasonably predicted. Although SPACE/sEM code has conservative models and correlations based on appendix K of 10 CFR 50, PCT does not exceed the requirement (1477 K). It is concluded that ECCS in APR1400 has a sufficient performance in cold-leg SBLOCA.

  20. 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

  1. Comparison of boundedness and monotonicity properties of one-leg and linear multistep methods

    KAUST Repository

    Mozartova, A.; Savostianov, I.; Hundsdorfer, W.

    2015-01-01

    © 2014 Elsevier B.V. All rights reserved. One-leg multistep methods have some advantage over linear multistep methods with respect to storage of the past results. In this paper boundedness and monotonicity properties with arbitrary (semi-)norms or convex functionals are analyzed for such multistep methods. The maximal stepsize coefficient for boundedness and monotonicity of a one-leg method is the same as for the associated linear multistep method when arbitrary starting values are considered. It will be shown, however, that combinations of one-leg methods and Runge-Kutta starting procedures may give very different stepsize coefficients for monotonicity than the linear multistep methods with the same starting procedures. Detailed results are presented for explicit two-step methods.

  2. Comparison of boundedness and monotonicity properties of one-leg and linear multistep methods

    KAUST Repository

    Mozartova, A.

    2015-05-01

    © 2014 Elsevier B.V. All rights reserved. One-leg multistep methods have some advantage over linear multistep methods with respect to storage of the past results. In this paper boundedness and monotonicity properties with arbitrary (semi-)norms or convex functionals are analyzed for such multistep methods. The maximal stepsize coefficient for boundedness and monotonicity of a one-leg method is the same as for the associated linear multistep method when arbitrary starting values are considered. It will be shown, however, that combinations of one-leg methods and Runge-Kutta starting procedures may give very different stepsize coefficients for monotonicity than the linear multistep methods with the same starting procedures. Detailed results are presented for explicit two-step methods.

  3. X-Ray Exam: Lower Leg (Tibia and Fibula)

    Science.gov (United States)

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

  4. Lower-leg symptoms in peripheral arterial disease are associated with anxiety, depression, and anhedonia

    DEFF Research Database (Denmark)

    Smolderen, Kim G; Hoeks, Sanne E; Pedersen, Susanne S.

    2009-01-01

    Patients with peripheral arterial disease (PAD) report diverse clinical manifestations that are not always consistent with classic intermittent claudication. We examined the degree to which atypical exertional leg symptoms, intermittent claudication, and exertional leg symptoms that begin at rest...... 2.5 and 4.0, p...

  5. Data report for ROSA-IV LSTF 10% hot leg break experiment Run SB-HL-02

    International Nuclear Information System (INIS)

    Kukita, Yutaka; Hirata, Kazuo; Gotou, Hiroki

    1990-03-01

    Experimental data for the 10% hot leg break test, Run SB-HL-02, conducted at the ROSA-IV Large Scale Test Facility (LSTF) on June 30, 1987, are presented. This test assumed total failure of both high pressure injection (HPI) and auxiliary feedwater (AFW) systems. The test results were characterized by asymmetric loop responses, flashing in the cold legs and upper downcomer, as well as condensation depressurization in the cold legs following injection of emergency core coolant (ECC) from accumulators. (author)

  6. A Case of Nonhealing Leg Ulcer: Basal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Didem Didar Balcı

    2008-06-01

    Full Text Available A 75-year-old woman was admitted to our outpatient clinic with a three-year history of a painless, nonhealing ulcer located on the left lower leg. She had no response to previous therapy with local wound care. Skin examination revealed an ulcer 2.7 x 3.7 cm in size, and the surrounding skin showed minimal erythema. The surface of the ulcer demonstrated shiny granulation tissue. Biopsy of the ulcer edge and base showed basal cell carcinoma. Venous Doppler ultrasonography and dermatological examination did not reveal chronic venous insufficiency. Basal cell carcinomas rarely arise from previous long-term ulcers or developing de novo. We suggest that patients who develop non-healing leg ulcers, should be examined for basal cell carcinoma.

  7. Novel Door-opening Method for Six-legged Robots Based on Only Force Sensing

    Science.gov (United States)

    Chen, Zhi-Jun; Gao, Feng; Pan, Yang

    2017-09-01

    Current door-opening methods are mainly developed on tracked, wheeled and biped robots by applying multi-DOF manipulators and vision systems. However, door-opening methods for six-legged robots are seldom studied, especially using 0-DOF tools to operate and only force sensing to detect. A novel door-opening method for six-legged robots is developed and implemented to the six-parallel-legged robot. The kinematic model of the six-parallel-legged robot is established and the model of measuring the positional relationship between the robot and the door is proposed. The measurement model is completely based on only force sensing. The real-time trajectory planning method and the control strategy are designed. The trajectory planning method allows the maximum angle between the sagittal axis of the robot body and the normal line of the door plane to be 45º. A 0-DOF tool mounted to the robot body is applied to operate. By integrating with the body, the tool has 6 DOFs and enough workspace to operate. The loose grasp achieved by the tool helps release the inner force in the tool. Experiments are carried out to validate the method. The results show that the method is effective and robust in opening doors wider than 1 m. This paper proposes a novel door-opening method for six-legged robots, which notably uses a 0-DOF tool and only force sensing to detect and open the door.

  8. Leg Stiffness in Female Soccer Players: Intersession Reliability and the Fatiguing Effects of Soccer-Specific Exercise.

    Science.gov (United States)

    De Ste Croix, Mark B A; Hughes, Jonathan D; Lloyd, Rhodri S; Oliver, Jon L; Read, Paul J

    2017-11-01

    De Ste Croix, MBA, Hughes, JD, Lloyd, RS, Oliver, JL, and Read, PJ. Leg stiffness in female soccer players: intersession reliability and the fatiguing effects of soccer-specific exercise. J Strength Cond Res 31(11): 3052-3058, 2016-Low levels of leg stiffness and reduced leg stiffness when fatigue is present compromise physical performance and increase injury risk. The purpose of this study was to (a) determine the reliability of leg stiffness measures obtained from contact mat data and (b) explore age-related differences in leg stiffness after exposure to a soccer-specific fatigue protocol in young female soccer players. Thirty-seven uninjured female youth soccer players divided into 3 subgroups based on chronological age (under 13 [U13], under 15 [U15], and under 17 [U17] year-olds) volunteered to participate in the study. After baseline data collection, during which relative leg stiffness, contact time, and flight time were collected, participants completed an age-appropriate soccer-specific fatigue protocol (SAFT). Upon completion of the fatigue protocol, subjects were immediately retested. Intersession reliability was acceptable and could be considered capable of detecting worthwhile changes in performance. Results showed that leg stiffness decreased in the U13 year-olds, was maintained in the U15 age group, and increased in the U17 players. Contact times and flight times did not change in the U13 and U15 year-olds, but significantly decreased and increased, respectively, in the U17 age group. The data suggest that age-related changes in the neuromuscular control of leg stiffness are present in youth female soccer players. Practitioners should be aware of these discrepancies in neuromuscular responses to soccer-specific fatigue, and should tailor training programs to meet the needs of individuals, which may subsequently enhance performance and reduce injury risk.

  9. 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.

  10. Well-leg compartment syndrome after gynecological laparoscopic surgery

    DEFF Research Database (Denmark)

    Boesgaard-Kjer, Diana H; Boesgaard-Kjer, Daniel; Kjer, Jens Jørgen

    2013-01-01

    Well-leg compartment syndrome in the lower extremities after surgery in the lithotomy position is a rare but severe complication requiring early diagnosis and intervention. Several circumstances predispose to this condition as a consequence of increased intra-compartmental pressure, such as posit...

  11. A legged anchoring mechanism for capsule endoscopes using micropatterned adhesives.

    Science.gov (United States)

    Glass, Paul; Cheung, Eugene; Sitti, Metin

    2008-12-01

    This paper presents a new concept for an anchoring mechanism to enhance existing capsule endoscopes. The mechanism consists of three actuated legs with compliant feet lined with micropillar adhesives to be pressed into the intestine wall to anchor the device at a fixed location. These adhesive systems are inspired by gecko and beetle foot hairs. Single-leg and full capsule mathematical models of the forces generated by the legs are analyzed to understand capsule performance. Empirical friction models for the interaction of the adhesives with an intestinal substrate were experimentally determined in vitro using dry and oil-coated elastomer micropillar arrays with 140 microm pillar diameter, 105 microm spacing between pillars, and an aspect ratio of 1:1 on fresh porcine small intestine specimens. Capsule prototypes were also tested in a simulated intestine environment and compared with predicted peristaltic loads to assess the viability of the proposed design. The experimental results showed that a deployed 10 gr capsule robot can withstand axial peristaltic loads and anchor reliably when actuation forces are greater than 0.27 N using dry micropillars. Required actuation forces may be reduced significantly by using micropillars coated with a thin silicone oil layer.

  12. Probenecid inhibits α-adrenergic receptor-mediated vasoconstriction in the human leg vasculature

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Piil, Peter Bergmann; Kiehn, Oliver Thistrup

    2018-01-01

    to α1- and α2-adrenergic receptor stimulation in the human forearm and leg vasculature of young healthy male subjects (23±3 years). By use of immunolabeling and confocal microscopy, Panx1 channels were found to be expressed in vascular smooth muscle cells of arterioles in human leg skeletal muscle....... Probenecid treatment increased (Padrenergic receptor stimulation) by ≈15%, whereas the response to the α1-agonist phenylephrine was unchanged. Inhibition...

  13. Popliteal amyloidoma presenting with leg ischemia in a chronic dialysis patient

    International Nuclear Information System (INIS)

    Aoki, Y.; Kaneda, Kiyoshi; Miyagi, Noboru; Itoh, Manabu; Ohmoto, Hirofumi

    2000-01-01

    The authors report a case of bilateral popliteal amyloidoma causing stenosis of the popliteal artery and vein. This patient had been treated with hemodialysis for 26 years. The diagnosis was made with MR angiography. A popliteal tumor of the right knee was resected surgically and the histologic examination showed deposition of amyloid. After resecting the popliteal tumor, the severe leg pain and intermittent claudication improved. This report suggests that popliteal amyloid tumors should be considered in a patient undergoing long-term hemodialysis who complains of leg pain and intermittent claudication. (orig.)

  14. The Role of Complex Treatment in Mixed Leg Ulcers - A Case Report of Vascular, Surgical and Physical Therapy.

    Science.gov (United States)

    Wollina, Uwe; Heinig, Birgit; Stelzner, Christian; Hansel, Gesina; Schönlebe, Jacqueline; Tchernev, Georgi; Lotti, Torello

    2018-01-25

    Leg ulcers are a burden to patients, their families and society. The second most common cause of chronic leg ulcers is the mixed arterio-venous type. An 80-year-old female patient presented to our department due to painful enlarging chronic leg ulcer of mixed arteriovenous origin on her left lower leg. She suffered from peripheral arterial occlusive disease stage I and chronic venous insufficiency Widmer grade IIIa, and a number of comorbidities. The aim of our ulcer treatment was a complete and stable wound closure that was hampered by arterial occlusion, exposed tendon, and renal insiffuciency. To improve the prognosis for ulcer surgery, we performed percutaneous transluminal angioplasty, transcutaneous CO 2 and deep ulcer shaving. The wound was closed by sandwich transplantation using elastin-collagen dermal template and meshed split skin graft. She had a 100% graft take with rapid reduction of severe wound pain. Complex approaches are necessary, to gain optimum results in leg ulcer therapy in mixed leg ulcers. Therapeutic nihilism should be abandonend.

  15. 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.

  16. Probabilitic analysis for fatigue failure of leg-supported liquid containers under random earthquake-type excitation

    International Nuclear Information System (INIS)

    Fujita, Takafumi

    1981-01-01

    Leg-supported cylindrical containers frequently used for nuclear power plants and chemical plants and leg-supported rectangular containers such as water and fuel tanks are the structures, of which the reliability is feared at the time of earthquakes. In this study, about such leg-supported liquid containers, the structural reliability of the system at the time of earthquakes was analyzed from the viewpoint of fatigue failure at the joints of tanks and supporting legs and the fixing parts of legs. The second order unsteady coupled probability density of response displacement and response velocity and the first and second order unsteady probability density of response displacement envelope were determined, then using the results, the expected value, variance and unsteady probability density of cumulative damage were obtained on the basis of Miner's law, thus the structural reliability of the system was analyzed. The result of analysis was verified with the results of vibration tests using many simulated earthquake waves, and the experiment of the fatigue failure of a model with sine wave vibration was carried out. The mechanical model for the analysis, the unsteady probability density described above, the analysis of structural reliability and the experiment are reported. (Kako, I.)

  17. Muscle activity of leg muscles during unipedal stance on therapy devices with different stability properties.

    Science.gov (United States)

    Wolburg, Thomas; Rapp, Walter; Rieger, Jochen; Horstmann, Thomas

    2016-01-01

    To test the hypotheses that less stable therapy devices require greater muscle activity and that lower leg muscles will have greater increases in muscle activity with less stable therapy devices than upper leg muscles. Cross-sectional laboratory study. Laboratory setting. Twenty-five healthy subjects. Electromyographic activity of four lower (gastrocnemius medialis, soleus, tibialis anterior, peroneus longus) and four upper leg muscles (vastus medialis and lateralis, biceps femoris, semitendinosus) during unipedal quiet barefoot stance on the dominant leg on a flat rigid surface and on five therapy devices with varying stability properties. Muscle activity during unipedal stance differed significantly between therapy devices (P < 0.001). The order from lowest to highest relative muscle activity matched the order from most to least stable therapy device. There was no significant interaction between muscle location (lower versus upper leg) and therapy device (P = 0.985). Magnitudes of additional relative muscle activity for the respective therapy devices differed substantially among lower extremity muscles. The therapy devices offer a progressive increase in training intensity, and thus may be useful for incremental training programs in physiotherapeutic practice and sports training programs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. 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.

  19. Leg blood pressure measured in orthostatic posture is associated with left ventricular mass in normotensive subjects.

    Science.gov (United States)

    Gemignani, Tiago; Matos-Souza, José R; Franchini, Kleber G; Nadruz, Wilson

    2012-10-01

    Changing from a supine to an orthostatic posture is associated with substantial increments in leg blood pressure (BP) levels, which could ultimately influence the hemodynamic burden imposed on the heart. This study investigated the relationship between brachial and leg BP measurements and the left cardiac chamber's structure and assessed the role of body posture changes in this regard. One hundred and thirty normotensive, nondiabetic, nonsmoking, normolipemic subjects were evaluated by a clinical history, anthropometry, the analysis of metabolic parameters, echocardiography, and the measurement of BP in the arm and the calf in both supine and orthostatic positions. Significant correlation coefficients between the leg BP measurements and the cardiac structure were detected, especially between the orthostatic pulse pressure (PP) and the left ventricular (LV) wall thickness (r = 0.38; P < 0.001), the orthostatic PP and the LV mass (r = 0.37; P < 0.001), and the orthostatic systolic BP (SBP) and the left atrial size (r = 0.35; P < 0.001). Stepwise and standard regression analysis adjusted for brachial BP and anthropometric and metabolic variables confirmed that the leg orthostatic PP was independently related to the LV wall thickness and mass. Moreover, the leg orthostatic SBP was associated with the left atrial dimension even after adding the LV mass to the statistical models. Finally, triglyceride levels and body surface area showed significant relationship with leg orthostatic PP and SBP, whereas brachial orthostatic PP and SBP were only associated with age and anthropometric variables. Orthostatic leg BP is independently associated with the cardiac structure in normotensive subjects.

  20. Investigation of Anticipatory Postural Adjustments during One-Leg Stance Using Inertial Sensors: Evidence from Subjects with Parkinsonism

    Directory of Open Access Journals (Sweden)

    Gianluca Bonora

    2017-07-01

    Full Text Available The One-Leg Stance (OLS test is a widely adopted tool for the clinical assessment of balance in the elderly and in subjects with neurological disorders. It was previously showed that the ability to control anticipatory postural adjustments (APAs prior to lifting one leg is significantly impaired by idiopathic Parkinson’s disease (iPD. However, it is not known how APAs are affected by other types of parkinsonism, such as frontal gait disorders (FGD. In this study, an instrumented OLS test based on wearable inertial sensors is proposed to investigate both the initial anticipatory phase and the subsequent unipedal balance. The sensitivity and the validity of the test have been evaluated. Twenty-five subjects with iPD presenting freezing of gait (FOG, 33 with iPD without FOG, 13 with FGD, and 32 healthy elderly controls were recruited. All subjects wore three inertial sensors positioned on the posterior trunk (L4–L5, and on the left and right frontal face of the tibias. Participants were asked to lift a foot and stand on a single leg as long as possible with eyes open, as proposed by the mini-BESTest. Temporal parameters and trunk acceleration were extracted from sensors and compared among groups. The results showed that, regarding the anticipatory phase, the peak of mediolateral trunk acceleration was significantly reduced compared to healthy controls (p < 0.05 in subjects with iPD with and without FOG, but not in FGD group (p = 0.151. Regarding the balance phase duration, a significant shortening was found in the three parkinsonian groups compared to controls (p < 0.001. Moreover, balance was significantly longer (p < 0.001 in iPD subjects without FOG compared to subjects with FGD and iPD subjects presenting FOG. Strong correlations between balance duration extracted by sensors and clinical mini-BESTest scores were found (ρ > 0.74, demonstrating the method’s validity. Our findings support the validity of the proposed

  1. Dynamic control for a quadruped locomotion robot in consideration of the leg-support-exchange phenomenon

    International Nuclear Information System (INIS)

    Sano, Akihito; Furusho, Junji; Okajima, Yosuke

    1988-01-01

    This paper proposes a new control method for quardruped walking robots in which the leg-support-exchange is lithely implemented. First, the authors formulate the leg-support-exchange phenomenon in 'Trot' using Lagrange's collision equation. Then the continuous walking can be numerically analyzed. Secondly, we propose a new control algorithm for leg-support-exchange. The conventional high gain local feedback causes many problems such as slip and excessive high torque in the leg-support-exchange phase of dynamic walking since it is impossible in this phase to prepare the proper reference values beforehand. In this algorithm, the control law is changed to 'free mode' or 'constant current mode' in order to adjust to the environment. The effectiveness of the proposed control strategy is confirmed by computer simulation and experiments using the walking robot 'COLT-1.' (author)

  2. Practical research of free standing rack. Seismic experiment study on full scale free standing rack

    International Nuclear Information System (INIS)

    Iwasaki, Akihisa; Nekomoto, Yoshitsugu; Morita, Hideyuki; Taniguchi, Katsuhiko; Okuno, Daisaku; Matsuoka, Toshihiro; Chigusa, Naoki

    2015-01-01

    The spent fuel taken out of a plant reactor is temporarily stored in a spent fuel rack. This fuel will often have to be stored in the rack for long periods before it can be moved to a reprocessing facility. Therefore, the spent fuel rack must have a high tolerance against big seismic loads. The free standing spent fuel rack has been developed as the optimal equipment meeting these requirements. It can be placed on the spent fuel pool floor without fixation to any support structure. Response of the free standing rack is reduced by the effect of the water and friction force on the spent fuel pool floor. For nuclear plant safety, it is necessary to understand the free standing rack behavior under earthquake in pools to verify the design of free standing racks and peripheral components. Several tests on a shaking table have been conducted on full-scale one free standing rack in air and in water, and sliding and rocking have been measured. The rack response is very complex and the study necessitates to take into account the sliding, the rocking, the effect of the water and of the arrangement of the fuel assemblies inside. (author)

  3. Minimally Actuated Walking: Identifying Core Challenges to Economical Legged Locomotion Reveals Novel Solutions

    Directory of Open Access Journals (Sweden)

    Ryan T Schroeder

    2018-05-01

    Full Text Available Terrestrial organisms adept at locomotion employ strut-like legs for economical and robust movement across the substrate. Although it is relatively easy to observe and analyze details of the solutions these organic systems have arrived at, it is not as easy to identify the problems these movement strategies have solved. As such, it is useful to investigate fundamental challenges that effective legged locomotion overcomes in order to understand why the mechanisms employed by biological systems provide viable solutions to these challenges. Such insight can inform the design and development of legged robots that may eventually match or exceed animal performance. In the context of human walking, we apply control optimization as a design strategy for simple bipedal walking machines with minimal actuation. This approach is used to discuss key facilitators of energetically efficient locomotion in simple bipedal walkers. Furthermore, we extrapolate the approach to a novel application—a theoretical exoskeleton attached to the trunk of a human walker—to demonstrate how coordinated efforts between bipedal actuation and a machine oscillator can potentially alleviate a meaningful portion of energetic exertion associated with leg function during human walking.

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

    OpenAIRE

    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 comm...

  5. Lumbopelvic muscle activation patterns in three stances under graded loading conditions: Proposing a tensegrity model for load transfer through the sacroiliac joints.

    Science.gov (United States)

    Pardehshenas, Hamed; Maroufi, Nader; Sanjari, Mohammad Ali; Parnianpour, Mohamad; Levin, Stephen M

    2014-10-01

    According to the conventional arch model of the pelvis, stability of the sacroiliac joints may require a predominance of form and force closure mechanisms: the greater the vertical shear force at the sacroiliac joints, the greater the reliance on self-bracing by horizontally or obliquely oriented muscles (such as the internal oblique). But what happens to the arch model when a person stands on one leg? In such cases, the pelvis no longer has imposts, leaving both the arch, and the arch model theory, without support. Do lumbopelvic muscle activation patterns in one-legged stances under load suggest compatibility with a different model? This study compares lumbopelvic muscle activation patterns in two-legged and one-legged stances in response to four levels of graded trunk loading in order to further our understanding the stabilization of the sacroiliac joints. Thirty male subjects experienced four levels of trunk loading (0%, 5%, 10% and 15% of body weight) by holding a bucket at one side, at three conditions: 1) two-legged standing with the bucket in the dominant hand, 2) ipsilateral loading: one-legged standing with the bucket in the dominant hand while using the same-side leg, and 3) contralateral loading: one-legged standing using the same leg used in condition 2, but with the bucket in the non-dominant hand. During these tasks, EMG signals from eight lumbopelvic muscles were collected. ANOVA with repeated design was performed on normalized EMG's to test the main effect of load and condition, and interaction effects of load by condition. Latissimus dorsi and erector spinae muscles showed an antagonistic pattern of activity toward the direction of load which may suggest these muscles as lateral trunk stabilizers. Internal oblique muscles showed a co-activation pattern with increasing task demand, which may function to increase lumbopelvic stability (P sacroiliac joint dysfunctions must be taken into consideration. Our hypothetical model may initiate thinking and

  6. Dynamics and Optimal Feet Force Distributions of a Realistic Four-legged Robot

    Directory of Open Access Journals (Sweden)

    Saurav Agarwal

    2012-08-01

    Full Text Available This paper presents a detailed dynamic modeling of realistic four-legged robot. The direct and inverse kinematic analysis for each leg has been considered in order to develop an overall kinematic model of the robot, when it follows a straight path. This study also aims to estimate optimal feet force distributions of the said robot, which is necessary for its real-time control. Three different approaches namely, minimization of norm of feet forces (approach 1, minimization of norm of joint torques (approach 2 and minimization of norm of joint power (approach 3 have been developed. Simulation result shows that approach 3 is more energy efficient foot force formulation than other two approaches. Lagrange-Euler formulation has been utilized to determine the joint torques. The developed dynamic models have been examined through computer simulation of continuous gait of the four-legged robot.

  7. Oxygen uptake during Wingate tests for arms and legs in swimmers and water polo players

    Directory of Open Access Journals (Sweden)

    Colantonio Emilson

    2003-01-01

    Full Text Available OBJECTIVE: The aim of the present study is to compare the values of the maximal oxygen uptake (O2 max during two consecutive bouts in Wingate tests for arms and legs in swimmers (S and water polo players (WP. METHODS: Sample - seven national level athletes (4 S and 3 WP, age 17,90 ± 2,14 years, body mass 71,41 ± 6,84 kg, height 176,65 ± 7,02 cm, % body fat 13,23 ± 4,18. Two Wingate bouts with 30 sec each with 3 min interval between them, for arms and legs in alternated days. Oxygen uptake: breath-by-breath using the gas analysis system K4 b² Cosmed. Statistical analysis: Wilcoxon test for dependent variables and Kolmogorov-Smirnov test for independent variables. RESULTS: The mean values found at the O2 peak (PO2, mean power (MP and peak power (PP for each bout of the Wingate test, for arms and legs. For Arms: PO2 = 55.16 ± 5.72 ml.kg-1.min-1, MP = 5.28 ± 0.59 watts.kg-1 and PP = 6.71 ± 0.88 watts.kg-1 got in the first bout (1st Arms and PO2 = 60.12 ± 6.10 ml.kg-1.min-1, MP = 5.03 ± 0.40 watts.kg-1 and PP = 6.25 ± 0.51 watts.kg-1, got in the second bout (2nd Arms. For legs: PO2 = 55.66 ± 6.85 ml.kg-1.min-1, MP = 4.75 ± 1.79 watts.kg-1 and PP = 7.44 ± 1.96 watts.kg-1 got in the first bout (1st Legs and PO2 = 62.09 ± 5.99 ml.kg-1.min-1, MP = 4.28 ± 1.47 watts.kg-1 and PP = 6.68 ± 1.63 watts.kg-1 got in the second bout (2nd Legs. DISCUSSION AND CONCLUSION: All variables studied did not present significant difference among arms and legs, as much the first as the second bout for arms for PO2 (p < 0.05. There was no difference between the PM mean values of the first and the second bout. But the mean of the second bout of legs was significant smaller than the first bout (p < 0.05. For the PP variable there was no difference among the mean values to the first and second bout as much for arms as for legs. It looks like to exist larger magnitude to O2 adjustment for arms than legs, that could be associated to specific demands to which S

  8. Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies.

    Science.gov (United States)

    Wayne, Peter M; Gow, Brian J; Costa, Madalena D; Peng, C-K; Lipsitz, Lewis A; Hausdorff, Jeffrey M; Davis, Roger B; Walsh, Jacquelyn N; Lough, Matthew; Novak, Vera; Yeh, Gloria Y; Ahn, Andrew C; Macklin, Eric A; Manor, Brad

    2014-01-01

    Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC) is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale "complexity" of postural sway fluctuations. To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults. A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience) adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO) and eyes-closed (EC). Anterior-posterior (AP) and medio-lateral (ML) sway speed, magnitude, and complexity (quantified by multiscale entropy) were calculated. Single-legged standing time and Timed-Up-and-Go tests characterized physical function. At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs), TC-experts (n = 27, age 62.8±7.5 yrs) exhibited greater complexity of sway in the AP EC (P = 0.023), ML EO (P<0.001), and ML EC (P<0.001) conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018). Long- and short-term TC training were positively associated with physical function. Multiscale entropy offers a complementary

  9. Complexity-Based Measures Inform Effects of Tai Chi Training on Standing Postural Control: Cross-Sectional and Randomized Trial Studies.

    Directory of Open Access Journals (Sweden)

    Peter M Wayne

    Full Text Available Diminished control of standing balance, traditionally indicated by greater postural sway magnitude and speed, is associated with falls in older adults. Tai Chi (TC is a multisystem intervention that reduces fall risk, yet its impact on sway measures vary considerably. We hypothesized that TC improves the integrated function of multiple control systems influencing balance, quantifiable by the multi-scale "complexity" of postural sway fluctuations.To evaluate both traditional and complexity-based measures of sway to characterize the short- and potential long-term effects of TC training on postural control and the relationships between sway measures and physical function in healthy older adults.A cross-sectional comparison of standing postural sway in healthy TC-naïve and TC-expert (24.5±12 yrs experience adults. TC-naïve participants then completed a 6-month, two-arm, wait-list randomized clinical trial of TC training. Postural sway was assessed before and after the training during standing on a force-plate with eyes-open (EO and eyes-closed (EC. Anterior-posterior (AP and medio-lateral (ML sway speed, magnitude, and complexity (quantified by multiscale entropy were calculated. Single-legged standing time and Timed-Up-and-Go tests characterized physical function.At baseline, compared to TC-naïve adults (n = 60, age 64.5±7.5 yrs, TC-experts (n = 27, age 62.8±7.5 yrs exhibited greater complexity of sway in the AP EC (P = 0.023, ML EO (P<0.001, and ML EC (P<0.001 conditions. Traditional measures of sway speed and magnitude were not significantly lower among TC-experts. Intention-to-treat analyses indicated no significant effects of short-term TC training; however, increases in AP EC and ML EC complexity amongst those randomized to TC were positively correlated with practice hours (P = 0.044, P = 0.018. Long- and short-term TC training were positively associated with physical function.Multiscale entropy offers a complementary

  10. Bed rest attenuates sympathetic and pressor responses to isometric exercise in antigravity leg muscles in humans.

    Science.gov (United States)

    Kamiya, Atsunori; Michikami, Daisaku; Shiozawa, Tomoki; Iwase, Satoshi; Hayano, Junichiro; Kawada, Toru; Sunagawa, Kenji; Mano, Tadaaki

    2004-05-01

    Although spaceflight and bed rest are known to cause muscular atrophy in the antigravity muscles of the legs, the changes in sympathetic and cardiovascular responses to exercises using the atrophied muscles remain unknown. We hypothesized that bed rest would augment sympathetic responses to isometric exercise using antigravity leg muscles in humans. Ten healthy male volunteers were subjected to 14-day 6 degrees head-down bed rest. Before and after bed rest, they performed isometric exercises using leg (plantar flexion) and forearm (handgrip) muscles, followed by 2-min postexercise muscle ischemia (PEMI) that continues to stimulate the muscle metaboreflex. These exercises were sustained to fatigue. We measured muscle sympathetic nerve activity (MSNA) in the contralateral resting leg by microneurography. In both pre- and post-bed-rest exercise tests, exercise intensities were set at 30 and 70% of the maximum voluntary force measured before bed rest. Bed rest attenuated the increase in MSNA in response to fatiguing plantar flexion by approximately 70% at both exercise intensities (both P antigravity leg muscles.

  11. Epidemiology, etiology, and treatment of chronic leg ulcer ...

    African Journals Online (AJOL)

    recovered accounting for 32.61% and 23.91%, respectively. Radiological investigation with plain. X-ray showed evidence of bony involvement in two patients. We managed our patients with wound dressing using. Table 1: Associated medical conditions seen in patients with chronic leg ulcer (n=60). Frequency Percent.

  12. 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

  13. Delivery of Compression Therapy for Venous Leg Ulcers

    DEFF Research Database (Denmark)

    Zarchi, Kian; Jemec, Gregor B E

    2014-01-01

    adequate subbandage pressure when treating patients with venous leg ulcers and the factors that predict the ability to achieve optimal pressure. DESIGN, SETTING, AND PARTICIPANTS: We performed a cross-sectional study from March 1, 2011, through March 31, 2012, in home care centers in 2 Danish...

  14. European guidelines on management of restless legs syndrome

    DEFF Research Database (Denmark)

    Garcia-Borreguero, Diego; Ferini-Strambi, Luigi; Kohnen, Ralf

    2012-01-01

    Since the publication of the first European Federation of Neurological Societies (EFNS) guidelines in 2005 on the management of restless legs syndrome (RLS; also known as Willis-Ekbom disease), there have been major therapeutic advances in the field. Furthermore, the management of RLS is now a pa...

  15. Presenting Symptoms in Pediatric Restless Legs Syndrome Patients

    NARCIS (Netherlands)

    de Weerd, Al; Arico, Irene; Silvestri, Rosalia

    2013-01-01

    Objective: The diagnosis restless legs syndrome (RLS) in children depends on the history told by the child and his parents. The description of symptoms given by the child him or herself is most important. Additional criteria are, among others, the results of polysomnography (PSG). Description of the

  16. Predicting a 10 repetition maximum for the free weight parallel squat using the 45 degrees angled leg press.

    Science.gov (United States)

    Willardson, Jeffrey M; Bressel, Eadric

    2004-08-01

    The purpose of this research was to devise prediction equations whereby a 10 repetition maximum (10RM) for the free weight parallel squat could be predicted using the following predictor variables: 10RM for the 45 degrees angled leg press, body mass, and limb length. Sixty men were tested over a 3-week period, with 1 testing session each week. During each testing session, subjects performed a 10RM for the free weight parallel squat and 45 degrees angled leg press. Stepwise multiple regression analysis showed leg press mass lifted to be a significant predictor of squat mass lifted for both the advanced and the novice groups (p squat mass lifted for the novice group and 55% of the variance in squat mass lifted for the advanced group. Limb length and body mass were not significant predictors of squat mass lifted for either group. The following prediction equations were devised: (a) novice group squat mass = leg press mass (0.210) + 36.244 kg, (b) advanced group squat mass = leg press mass (0.310) + 19.438 kg, and (c) subject pool squat mass = leg press mass (0.354) + 2.235 kg. These prediction equations may save time and reduce the risk of injury when switching from the leg press to the squat exercise.

  17. 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)

  18. The mechanical development and construction of the insulating legs for the NSF tandem

    International Nuclear Information System (INIS)

    Leese, J.M.

    1978-06-01

    The Science Research Council is constructing at its Daresbury Laboratory a 30 MV tandem Van de Graaff accelerator which will be used as a research tool to accelerate ions of a wide range of elements. Ions are accelerated through an evacuated beam tube by maintaining a high electric field along it. The ion beam is steered and focussed by magnets situated at various positions along the tube, which, together with the beam handling elements, is supported by a vertical insulating stack. The stack consists of eight vertical columns tied together at regular intervals by stiff rings to obtain the necessary mechanical stability. Each column is made up of 'insulating legs' with tubular steel legs at the terminal and dead section positions. This report describes the manufacturing processes and their development for the insulating legs. (author)

  19. Transformation of solar radiation in Norway spruce stands into produced biomass - the effect of stand density

    International Nuclear Information System (INIS)

    Marková, I.; Marek, M.V.; Pokorný, R.

    2011-01-01

    The present paper is focused on the assessment of the effects of stand density and leaf area development on radiation use efficiency in the mountain cultivated Norway spruce stand. The young even-aged (17-years-old in 1998) plantation of Norway spruce was divided into two experimental plots differing in their stand density in 1995. During the late spring of 2001 next cultivating high-type of thinning of 15% intensity in a reduction of stocking density was performed. The PAR regime of investigated stands was continually measured since 1992. Total aboveground biomass (TBa) and TBa increment were obtained on the basis of stand inventory. The dynamic of LAI development showed a tendency to be saturated, i.e. the LAI value close to 11 seems to be maximal for the local conditions of the investigated mountain cultivated Norway spruce stand in the Beskids Mts. Remarkable stimuli (up to 17%) of LAI formation were started in 2002, i.e. as an immediate response to thinning. Thus, the positive effect of thinning on LAI increase was confirmed. The data set of absorbed PAR and produced TBa in the period 1998-2003 was processed by the linear regression of Monteith's model, which provided the values of the coefficient of solar energy conversion efficiency into biomass formation. The differences in biomass formation values between the dense and sparse plot after thinning amounted to 18%

  20. 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.