Humeral retroversion and shoulder rotational mobility in young handball practitioners.

PubMed

Quadros, Gustavo Aguiar; Döhnert, Marcelo Baptista

2015-01-01

: To evaluate the prevalence of humeral retroversion and rotational mobility (RHH) in young handball practitioners and non-practitioners. : This is a cross-sectional study performed with two groups: the handball group, with 14 female students practicing handball and the control group, with 13 young participants non-practicing pitch sports. : The handball group presented full rotational movement (FRM) hi-gher than the control group in both the dominant shoulder (p=0.001) and the non-dominant shoulder (p=0.0001). The mobility of active and passive internal rotation was significantly higher in handball players in both shoulders. The handball group presented lower internal rotation range of motion for the dominant shoulder as compared to the non-dominant shoul-der (p=0.001). : Young handball practitioners, des-pite skeletally immature, showed a higher MRT than the control group. The handball group showed loss of internal rotation (medial) on the dominant shoulder as compared to the non--dominant shoulder. Level of Evidence II, Prospective Study.

Isolation of rotational isomers and developments derived therefrom

PubMed Central

ŌKI, Michinori

2010-01-01

Isolation of rotational isomer models of ethane-type molecules is described. We could experimentally prove that, if rotational isomers whose molecular shape was chiral, the molecule could be optically active, even though it did not carry an asymmetric carbon atom. As an extension, other types of stereochemically fundamental and optically active molecules were isolated and their absolute stereochemistry was determined. One example is the model of meso-tartaric acid, for which optical inactivity had been attributed to internal compensation but is now explained as follows. On dissolution of meso-tartaric acid in a solvent, the molecule gives two kinds of conformers, one of which is a Ci molecule and the other is a C1 molecule. Although the latter is intrinsically optically active, the optical activity is cancelled by its enantiomer. The theory of internal compensation is recommended to be abandoned. As an extension to another area, some reactions of conformers are also discussed. PMID:21084771

Rotation in a reversed field pinch with active feedback stabilization of resistive wall modes

NASA Astrophysics Data System (ADS)

Cecconello, M.; Menmuir, S.; Brunsell, P. R.; Kuldkepp, M.

2006-09-01

Active feedback stabilization of multiple resistive wall modes (RWMs) has been successfully proven in the EXTRAP T2R reversed field pinch. One of the features of plasma discharges operated with active feedback stabilization, in addition to the prolongation of the plasma discharge, is the sustainment of the plasma rotation. Sustained rotation is observed both for the internally resonant tearing modes (TMs) and the intrinsic impurity oxygen ions. Good quantitative agreement between the toroidal rotation velocities of both is found: the toroidal rotation is characterized by an acceleration phase followed, after one wall time, by a deceleration phase that is slower than in standard discharges. The TMs and the impurity ions rotate in the same poloidal direction with also similar velocities. Poloidal and toroidal velocities have comparable amplitudes and a simple model of their radial profile reproduces the main features of the helical angular phase velocity. RWMs feedback does not qualitatively change the TMs behaviour and typical phenomena such as the dynamo and the 'slinky' are still observed. The improved sustainment of the plasma and TMs rotation occurs also when feedback only acts on internally non-resonant RWMs. This may be due to an indirect positive effect, through non-linear coupling between TMs and RWMs, of feedback on the TMs or to a reduced plasma-wall interaction affecting the plasma flow rotation. Electromagnetic torque calculations show that with active feedback stabilization the TMs amplitude remains well below the locking threshold condition for a thick shell. Finally, it is suggested that active feedback stabilization of RWMs and current profile control techniques can be employed simultaneously thus improving both the plasma duration and its confinement properties.

Interactive modeling activities in the classroom—rotational motion and smartphone gyroscopes

NASA Astrophysics Data System (ADS)

Pörn, Ray; Braskén, Mats

2016-11-01

The wide-spread availability of smartphones makes them a valuable addition to the measurement equipment in both the physics classroom and the instructional laboratory, encouraging an active interaction between measurements and modeling activities. In this paper we illustrate this interaction by making use of the internal gyroscope of a smartphone to study and measure the rotational dynamics of objects rotating about a fixed axis. The workflow described in this paper has been tested in a classroom setting and found to encourage an exploratory approach to both data collecting and modeling.

Relationship between extrinsic factors and the acromio-humeral distance.

PubMed

Mackenzie, Tanya Anne; Herrington, Lee; Funk, Lenard; Horsley, Ian; Cools, Ann

2016-06-01

Maintenance of the subacromial space is important in impingement syndromes. Research exploring the correlation between biomechanical factors and the subacromial space would be beneficial. To establish if relationship exists between the independent variables of scapular rotation, shoulder internal rotation, shoulder external rotation, total arc of shoulder rotation, pectoralis minor length, thoracic curve, and shoulder activity level with the dependant variables: AHD in neutral, AHD in 60° arm abduction, and percentage reduction in AHD. Controlled laboratory study. Data from 72 male control shoulders (24.28years STD 6.81 years) and 186 elite sportsmen's shoulders (25.19 STD 5.17 years) were included in the analysis. The independent variables were quantified and real time ultrasound was used to measure the dependant variable acromio-humeral distance. Shoulder internal rotation and pectoralis minor length, explained 8% and 6% respectively of variance in acromio-humeral distance in neutral. Pectoralis minor length accounted for 4% of variance in 60° arm abduction. Total arc of rotation, shoulder external rotation range, and shoulder activity levels explained 9%, 15%, and 16%-29% of variance respectively in percentage reduction in acromio-humeral distance during arm abduction to 60°. Pectorals minor length, shoulder rotation ranges, total arc of shoulder rotation, and shoulder activity levels were found to have weak to moderate relationships with acromio-humeral distance. Existence and strength of relationship was population specific and dependent on arm position. Relationships only accounted for small variances in AHD indicating that in addition to these factors there are other factors involved in determining AHD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Descriptive profile of hip range of motion in elite tennis players.

PubMed

Moreno-Pérez, Victor; Ayala, Francisco; Fernandez-Fernandez, Jaime; Vera-Garcia, Francisco J

2016-05-01

To describe the range of motion (ROM) profile (flexion, extension, abduction, internal and external rotation) of the hip in elite tennis players; and (b) to analyse if there are sex-related differences in the hip ROM. Cohort study. Controlled laboratory environment. 81 male and 28 female tennis players completed this study. Descriptive measures of passive hip flexion, extension and abduction, and internal and external active and passive hip rotation ROM were taken. Magnitude-based inferences on differences between sex (males vs. females) and hip (dominant vs. non-dominant) were made by standardising differences. No clinically meaningful bilateral and sex-related differences in any of the hip ROM measures. In addition, it was found that both males and females had restricted mobility measures on hip flexion (<80°), extension (<0°) and abduction (<40°). Furthermore, the 30% of males also presented restricted active and passive hip internal rotation ROM values (<25°). Finally, both males and females had normal mobility measures of hip external rotation ROM (active [>25°] and passive [35°]) Asymmetric hip joint ROM measures found during clinical examination and screening may indicate abnormalities and the need of rehabilitation (e.g., flexibility training). In addition, clinicians should include specific exercises (e.g., stretching) in their conditioning, prevention and rehabilitation programmes aiming to avoid restricted mobility of hip flexion (males = 74°; females = 78°), extension (males = -1.5; females = -0.4), abduction (males = 35°; females = 34°) and internal rotation (males = 30°; females = 35) that might be generated as a consequence of playing tennis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Maxillary movement in distraction osteogenesis using internal devices in cleft palate patients.

PubMed

Tomita, Daisuke; Omura, Susumu; Ozaki, Shusaku; Shimazaki, Kazuo; Fukuyama, Eiji; Tohnai, Iwai; Torikai, Katsuyuki

2011-03-01

The purpose of this cephalometric study was to compare the actual movement with the planned movement of the maxilla by using internal maxillary distraction in cleft lip and palate patients. Twelve patients, including eight with unilateral and four with bilateral cleft lip and palate, underwent maxillary advancement with internal maxillary distractors. Lateral cephalometric radiographs obtained preoperatively, predistraction, and postdistraction were used for analysis. The movement of the maxilla, angular change of the internal devices and rotation of the mandible were measured at each stage, and the planned vector of advancement predicted from the placement vector of the distractors was compared with the actual vector. Internal maxillary distractors were rotated in a clockwise direction during the distraction period. The angular change of the distractors was 7.7°. The amount of actual advancement at anterior nasal spine with distraction was 6.3 mm, which represented about 70% of the distance of activation of distraction. The actual advanced vector at anterior nasal spine was 9.7° smaller than the planned vector. The mandible underwent a clockwise rotation of 3.5°. In the internal distraction technique, the maxilla was advanced inferiorly to the planned vector and with a slight clockwise rotation. These results are useful for surgical planning when using internal distractors.

Three-dimensional scapular kinematics during the throwing motion.

PubMed

Meyer, Kristin E; Saether, Erin E; Soiney, Emily K; Shebeck, Meegan S; Paddock, Keith L; Ludewig, Paula M

2008-02-01

Proper scapular motion is crucial for normal shoulder mechanics. Scapular motion affects glenohumeral joint function during throwing, yet little is known about this dynamic activity. Asymptomatic subjects (10 male and 10 female), ages 21 to 45, were analyzed. Electromagnetic surface sensors on the sternum, acromion, and humerus were used to collect 3-D motion data during three trials of low-velocity throwing. Scapular angular position data were described or five predetermined events throughout the throw corresponding with classic descriptions of throwing phases, and trial-to-trial reliability was determined. ANOVA compared scapular angles across events. Subjects demonstrated good to excellent reliability between trials of the throw (ICC 0.74-0.98). The scapula demonstrated a pattern of external rotation, upward rotation (peak of approx. 40 degrees), and poster humeral horizontal abduction. During the arm acceleration phase, the scapula moved toward greater internal rotation and began anteriorly tilting. At maximum humeral internal rotation, the scapula ended in internal rotation (55 degrees), upward rotation (20 degrees), and anterior tilting (3 degrees). Significant differences in scapular position (p<0.05) were identified across the throwing motion. Scapular data identify events in the throwing motion in which throwers may be more susceptible to shoulder pathologies related to abnormal scapular kinematics.

A randomized controlled comparison of stretching procedures for posterior shoulder tightness.

PubMed

McClure, Philip; Balaicuis, Jenna; Heiland, David; Broersma, Mary Ellen; Thorndike, Cheryl K; Wood, April

2007-03-01

Randomized controlled trial, To compare changes in shoulder internal rotation range of motion (ROM), for 2 stretching exercises, the "cross-body stretch" and the "sleeper stretch," in individuals with posterior shoulder tightness. Recently, some authors have expressed the belief that the sleeper stretch is better than the cross-body stretch to address glenohumeral posterior tightness because the scapula is stabilized. Fifty-four asymptomatic subjects (20 males, 34 females) participated in the study. The control group (n=24) consisted of subjects with a between-shoulder difference in internal rotation ROM of less than 10 degrees, whereas those subjects with more than a 10 degrees difference were randomly assigned to 1 of 2 intervention groups, the sleeper stretch group (n=15) or the cross-body stretch group (n=15). Shoulder internal rotation ROM, with the arm abducted to 90 degrees and scapula motion prevented, was measured before and after a 4-week intervention period. Subjects in the control group were asked not to engage in any new stretching activities, while subjects in the 2 stretching groups were asked to perform stretching exercises on the more limited side only, once daily for 5 repetitions, holding each stretch for 30 seconds. The improvements in internal rotation ROM for the subjects in the cross-body stretch group (mean +/- SD, 20.0 degrees +/- 12.9 degrees) were significantly greater than for the subjects in the control group (5.9 degrees +/- 9.4 degrees, P = .009). The gains in the sleeper stretch group (12.4 degrees +/- 10.4 degrees) were not significant compared to those of the control group (P = .586) and those of the cross-body stretch group (P = .148). The cross-body stretch in individuals with limited shoulder internal rotation ROM appears to be more effective than no stretching in controls without internal rotation asymmetry to improve shoulder internal rotation ROM. While the improvement in internal rotation from the cross-body stretch was greater than for the sleeper stretch and of a magnitude that could be clinically significant, the small sample size likely precluded statistical significance between groups.

Scapular Contribution for the End-Range of Shoulder Axial Rotation in Overhead Athletes

PubMed Central

Ribeiro, Andrea; Pascoal, Augusto Gil

2012-01-01

The aim of this study was to analyze the relative contribution of the scapular motion on the extreme range-of-motion of shoulder external and internal rotation, in overhead athletes. An electromagnetic tracking device (Flock of Birds) was used to record humeral and scapular kinematics. The dominant arm of 26 male subjects (13 athletes and 13 non-athletes) was studied while subjects actively reached end-range of internal and external rotation. Humeral and scapular angles were calculated and compared across groups by means of a t-test for independent samples. A bivariate correlation approach was used to describe the relationship between humeral angles and scapular variables. The range-of-motion of the thoracohumeral angles, during shoulder external rotation was significantly less (p < 0.05) on the athletes group, athletes also positioned their dominant scapula more retracted and posteriorly tilted. A positive correlation was found between glenohumeral angles and scapular tilt (r = 0.6777; p < 0.05). Concerning internal rotation; athletes showed significantly greater (highest) thoracohumeral angles (p < 0.05). Scapula assumed a position more in retraction and anterior tilt. Based on these findings, it is suggested that differences found in athletes seem to reveal an eventual shoulder adaptation to the throwing mechanics. Key points In external rotation end-range, athletes positioned their scapula more in retraction and posterior tilt. In internal rotation end-range, athletes positioned their scapula more in retraction and anterior tilt. Results seem to reveal a sport-related shoulder adaptation. PMID:24150078

Shoulder internal rotation elbow flexion test for diagnosing cubital tunnel syndrome.

PubMed

Ochi, Kensuke; Horiuchi, Yukio; Tanabe, Aya; Waseda, Makoto; Kaneko, Yasuhito; Koyanagi, Takahiro

2012-06-01

Shoulder internal rotation enhances symptom provocation attributed to cubital tunnel syndrome. We present a modified elbow flexion test--the shoulder internal rotation elbow flexion test--for diagnosing cubital tunnel syndrome. Fifty-five ulnar nerves in cubital tunnel syndrome patients and 123 ulnar nerves in controls were examined with 5 seconds each of elbow flexion, shoulder internal rotation, and shoulder internal rotation elbow flexion tests before and after treatment (surgery in 18; conservative in others). For the shoulder internal rotation elbow flexion test position, 90° abduction, maximum internal rotation, and 10° flexion of the shoulder were combined with the elbow flexion test position. The test was considered positive if any symptom for cubital tunnel syndrome developed <5 seconds. Influence of the shoulder internal rotation elbow flexion test was evaluated by nerve conduction studies in 10 cubital tunnel syndrome nerves and 7 control nerves. The sensitivities/specificities of the 5-second elbow flexion, shoulder internal rotation, and shoulder internal rotation elbow flexion tests were 25%/100%, 58%/100%, and 87%/98%, respectively. Sensitivity differences between the shoulder internal rotation elbow flexion test and the other two tests were significant. Shoulder internal rotation elbow flexion test results and cubital tunnel syndrome symptoms were significantly correlated. Influence of the shoulder internal rotation elbow flexion test on the ulnar nerve was seen in 8 of 10 cubital tunnel syndrome nerves but not in controls. The 5-second shoulder internal rotation elbow flexion test is specific, easy and quick provocative test for diagnosing cubital tunnel syndrome. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

An observational study of emergency department intern activities.

PubMed

Zhu, Jia Ni; Weiland, Tracey J; Taylor, David M; Dent, Andrew W

2008-05-05

To describe how intern time is spent, and the frequency of activities performed by interns during emergency department (ED) rotations. Prospective observational study of 42 ED interns from three Melbourne city teaching hospitals during 5 months in 2006. Direct observations were made by a single researcher for 390.8 hours, sampling all days of the week and all hours of the day. Proportion of time spent on tasks and number of procedures performed or observed by interns. Direct patient-related tasks accounted for 86.6% of total intern time, including 43.9% spent on liaising and documentation, 17.5% obtaining patient histories, 9.3% on physical examinations, 5.6% on procedures, 4.8% ordering or interpreting investigations, 3.0% on handover and 4.9% on other clinical activities. Intern time spent on non-clinical activities included 4.2% on breaks, 3.7% on downtime, 1.7% on education, and 1.3% on teaching others. Adjusted for an 8-week term, the ED intern would take 253 patient histories, consult more senior ED staff on 683 occasions, perform 237 intravenous cannulations/phlebotomies, 39 arterial punctures, 12 wound repairs and apply 16 plasters. They would perform chest compressions under supervision on seven occasions, observe defibrillation twice and intubation once, but may not see a thoracostomy. The ED exposes interns to a broad range of activities. With the anticipated increase in intern numbers, dilution of the emergency medicine experience may occur, and requirements for supervision may increase. Substitution of ED rotations may deprive interns of a valuable learning experience.

Glenohumeral joint rotation range of motion in competitive swimmers.

PubMed

Riemann, Bryan L; Witt, Joe; Davies, George J

2011-08-01

Much research has examined shoulder range of motion adaptations in overhead-unilateral athletes. Based on the void examining overhead-bilateral athletes, especially competitive swimmers, we examined shoulder external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion of competitive swimmers. The range of motion of registered competitive swimmers (n = 144, age = 12-61 years) was compared by limb (dominant, non-dominant), sex, and age group (youth, high school, college, masters). Significantly (P < 0.05) greater dominant external rotation was observed for both men and women high school and college swimmers, youth women swimmers, and men masters swimmers compared with the non-dominant limb. The isolated internal rotation (glenohumeral rotation), composite internal rotation (glenohumeral rotation plus scapulothoracic protraction), and total arc of motion (external rotation plus composite internal rotation) of the non-dominant limb was significantly greater than that of the dominant limb by sex and age group. Youth and high school swimmers demonstrated significantly greater composite internal rotation than college and masters swimmers. Youth swimmers displayed significantly greater total arc of motion than all other age groups. These data will aid in the interpretation of shoulder range of motion values in competitive swimmers during preseason screenings, injury evaluations and post-rehabilitation programmes, with the results suggesting that differences exist in bilateral external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion.

Single Neurons in M1 and Premotor Cortex Directly Reflect Behavioral Interference

PubMed Central

Zach, Neta; Inbar, Dorrit; Grinvald, Yael; Vaadia, Eilon

2012-01-01

Some motor tasks, if learned together, interfere with each other's consolidation and subsequent retention, whereas other tasks do not. Interfering tasks are said to employ the same internal model whereas noninterfering tasks use different models. The division of function among internal models, as well as their possible neural substrates, are not well understood. To investigate these questions, we compared responses of single cells in the primary motor cortex and premotor cortex of primates to interfering and noninterfering tasks. The interfering tasks were visuomotor rotation followed by opposing visuomotor rotation. The noninterfering tasks were visuomotor rotation followed by an arbitrary association task. Learning two noninterfering tasks led to the simultaneous formation of neural activity typical of both tasks, at the level of single neurons. In contrast, and in accordance with behavioral results, after learning two interfering tasks, only the second task was successfully reflected in motor cortical single cell activity. These results support the hypothesis that the representational capacity of motor cortical cells is the basis of behavioral interference and division between internal models. PMID:22427923

A UV spectroscopic survey of periodic M dwarfs in the Hyades

NASA Astrophysics Data System (ADS)

Agueros, Marcel

2017-08-01

Because of its proximity, the 650-Myr-old Hyades open cluster is a unique resource for exploring the relationship between magnetic activity, rotation, and age in low-mass stars. While the cluster has been largely ignored in UV studies of the dependence of activity on rotation, we now have an extensive and growing set of complementary rotation period, Halpha, and X-ray measurements with which to examine in detail the rotation-activity relation at 650 Myr and to constrain theories of magnetic heating. We propose to measure Mg II line emission, the strongest NUV activity tracer, in COS spectra of 17 Hyads ranging in spectral type from M0 to M7 with known rotation periods and Halpha and X-ray measurements. These stars form a representative sample of M-dwarf Hyads with known periods and are a significant addition to, and expansion of, the sample of 20 mainly solar-mass rotators with existing (mostly low-resolution) International Ultravioled Explorer (IUE) NUV spectra. The Mg II measurements will contribute significantly to our goal of mapping out the rotation-activity relation star-by-star in this benchmark open cluster. This, in turn, will move us toward an improved understanding of the radiation environment and habitability of the exoplanets we continue to find around low-mass stars.

Trunk and hip biomechanics influence anterior cruciate loading mechanisms in physically active participants.

PubMed

Frank, Barnett; Bell, David R; Norcross, Marc F; Blackburn, J Troy; Goerger, Benjamin M; Padua, Darin A

2013-11-01

Excessive trunk motion and deficits in neuromuscular control (NMC) of the lumbopelvic hip complex are risk factors for anterior cruciate ligament (ACL) injury. However, the relationship between trunk motion, NMC of the lumbopelvic hip complex, and triplanar knee loads during a sidestep cutting task has not been examined. To determine if there is an association between multiplanar trunk motion, NMC of the lumbopelvic hip complex, and triplanar knee loads with ACL injury during a sidestep cutting task. Descriptive laboratory study. The hip and knee biomechanics and trunk motion of 30 participants (15 male, 15 female) were analyzed during a sidestep cutting task using an optoelectric camera system interfaced to a force plate. Trunk and lower extremity biomechanics were calculated from the kinematic and ground-reaction force data during the first 50% of the stance time during the cutting task. Pearson product moment correlation coefficients were calculated between trunk and lower extremity biomechanics. Multiple linear regression analyses were carried out to determine the amount of variance in triplanar knee loading explained by trunk motion and hip moments. A greater internal knee varus moment (mean, 0.11 ± 0.12 N·m/kg*m) was associated with less transverse-plane trunk rotation away from the stance limb (mean, 20.25° ± 4.42°; r = -0.46, P = .011) and a greater internal hip adduction moment (mean, 0.33 ± 0.25 N·m/kg*m; r = 0.83, P < .05). A greater internal knee external rotation moment (mean, 0.11 ± 0.08 N·m/kg*m) was associated with a greater forward trunk flexion (mean, 7.62° ± 5.28°; r = 0.42, P = .020) and a greater hip internal rotation moment (mean, 0.15 ± 0.16 N·m/kg*m; r = 0.59, P = .001). Trunk rotation and hip adduction moment explained 81% (P < .05) of the variance in knee varus moment. Trunk flexion and hip internal rotation moment explained 48% (P < .05) of the variance in knee external rotation moment. Limited trunk rotation displacement toward the new direction of travel and hip adduction moment are associated with an increased internal knee varus moment, while a combined increase in trunk flexion displacement and hip internal rotation moment is associated with a higher internal knee external rotation moment. Prevention interventions for ACL injury should encourage trunk rotation toward the new direction of travel and limit excessive trunk flexion while adjusting frontal- and transverse-plane hip NMC.

Flexibility of internal and external glenohumeral rotation of junior female tennis players and its correlation with performance ranking.

PubMed

Chiang, Ching-Cheng; Hsu, Chih-Chia; Chiang, Jinn-Yen; Chang, Weng-Cheng; Tsai, Jong-Chang

2016-12-01

[Purpose] The purpose of this study was to compare the internal and external rotation of the dominant and nondominant shoulders of adolescent female tennis players. The correlation between the shoulder rotation range of motion and the player's ranking was also analyzed. [Subjects and Methods] Twenty-one female junior tennis players who were 13 to 18 years old participated in this study. A standard goniometer was used to measure the internal and external rotation of both glenohumeral joints. The difference in internal and external rotation was calculated as the glenohumeral rotation deficit. The year-end ranking of each player was obtained from the Chinese Taipei Tennis Association. [Results] The internal rotation of the dominant shoulder was significantly smaller than that of the nondominant shoulder. Moreover, player ranking was significantly and negatively correlated with the internal rotation range of motion of both shoulders. On the other hand, the correlations of the internal and external rotation ranges of motion with the age, height, and weight were not significant. [Conclusion] The flexibility of the glenohumeral internal rotation is smaller in the dominant shoulder than of the nondominant shoulder in these junior female tennis players. Flexibility of the glenohumeral internal rotation may be a factor affecting performance in junior female tennis players.

Restoration of Full Shoulder Range of Motion After Application of the Fascial Distortion Model.

PubMed

Boucher, Joshua D; Figueroa, Jose

2018-05-01

Decreased active and passive range of motion (ROM) accompanied by pain in the shoulder is a common presentation for patients with frozen shoulder, and it can be difficult to restore normal function. Through the fascial distortion model, physicians can apply a manual technique to rapidly and effectively increase ROM and decrease pain. A 28-year-old man presented 18 months after sustaining a shoulder hyperextension injury. On active and passive ROM examination, he had approximately 90° of shoulder abduction and moderately reduced internal rotation associated with 8/10 pain. After 2 applications of the fascial distortion model, his shoulder restored to full abduction and internal rotation with no pain.

Comparison of Shoulder Range of Motion, Strength, and Playing Time in Uninjured High School Baseball Pitchers Who Reside in Warm- and Cold-Weather Climates

PubMed Central

Kaplan, Kevin M.; ElAttrache, Neal S.; Jobe, Frank W.; Morrey, Bernard F.; Kaufman, Kenton R.; Hurd, Wendy J.

2014-01-01

Background There is an assumption that baseball athletes who reside in warm-weather climates experience larger magnitude adaptations in throwing shoulder motion and strength compared with their peers who reside in cold-weather climates. Hypotheses (1) The warm-weather climate (WWC) group would exhibit more pronounced shoulder motion and strength adaptations than the cold-weather climate (CWC) group, and (2) the WWC group would participate in pitching activities for a greater proportion of the year than the CWC group, with the time spent pitching predicting throwing shoulder motion and strength in both groups. Study Design Cross-sectional study; Level of evidence, 3. Methods One hundred uninjured high school pitchers (50 each WWC, CWC) were recruited. Rotational shoulder motion and isometric strength were measured and participants reported the number of months per year they pitched. To identify differences between groups, t tests were performed; linear regression was used to determine the influence of pitching volume on shoulder motion and strength. Results The WWC group pitched more months per year than athletes from the CWC group, with the number of months spent pitching negatively related to internal rotation motion and external rotation strength. The WWC group exhibited greater shoulder range of motion in all planes compared with the CWC group, as well as significantly lower external rotation strength and external/internal rotation strength ratios. There was no difference in internal rotation strength between groups, nor a difference in the magnitude of side-to-side differences for strength or motion measures. Conclusion Athletes who reside in cold- and warm-weather climates exhibit differences in throwing shoulder motion and strength, related in part to the number of months spent participating in pitching activities. The amount of time spent participating in pitching activities and the magnitude of range of motion and strength adaptations in athletes who reside in warm-weather climates may make these athletes more susceptible to throwing-related injuries. PMID:21051421

A 12-week rehabilitation program improves body composition, pain sensation, and internal/external torques of baseball pitchers with shoulder impingement symptom.

PubMed

Cha, Jun-Youl; Kim, Jae-Hak; Hong, Ju; Choi, Young-Tae; Kim, Min-Ho; Cho, Ji-Hyun; Ko, Il-Gyu; Jee, Yong-Seok

2014-02-01

The aim of this study was to investigate the effects of a 12-week rehabilitation program on body composition, shoulder pain, and isokinetic internal/external torques of pitchers with impingement syndrome. A total of 30 pitchers were divided into 2 groups: experimental group (EG, n = 16) and control group (CG, n= 14). The rehabilitation program consisted of physical therapy, warm-up, work-out, and cool-down. As results, body weight and fat mass of EG were decreased whereas muscle mass of EG was significantly increased after the experiment. The pain degrees in resting, normal daily activity, and strenuous activity on the numeric pain rating scale were significantly decreased in the EG. The internal and external peak torques (PTs) of uninvolved and involved sides of EG were increased in EG after 12 weeks. Such results provide a deficit ratio of both sides in EG close to normal values. The ratios of internal/external PTs in EG were also close to the reference values. The internal and external total works of both sides in EG were similar to the values of PT. The fatigue indices of internal and external rotators of both sides in EG were decreased. As a conclusion, a 12-week rehabilitation program reduced the shoulder pain, improved the body composition and enhanced the isokinetic shoulder internal/external rotators in EG with impingement symptoms. Also the study suggested that the rehabilitation program evened out the ratio between internal and external rotators and lowered the fatigue level after the experiment.

A 12-week rehabilitation program improves body composition, pain sensation, and internal/external torques of baseball pitchers with shoulder impingement symptom

PubMed Central

Cha, Jun-Youl; Kim, Jae-Hak; Hong, Ju; Choi, Young-Tae; Kim, Min-Ho; Cho, Ji-Hyun; Ko, Il-Gyu; Jee, Yong-Seok

2014-01-01

The aim of this study was to investigate the effects of a 12-week rehabilitation program on body composition, shoulder pain, and isokinetic internal/external torques of pitchers with impingement syndrome. A total of 30 pitchers were divided into 2 groups: experimental group (EG, n = 16) and control group (CG, n= 14). The rehabilitation program consisted of physical therapy, warm-up, work-out, and cool-down. As results, body weight and fat mass of EG were decreased whereas muscle mass of EG was significantly increased after the experiment. The pain degrees in resting, normal daily activity, and strenuous activity on the numeric pain rating scale were significantly decreased in the EG. The internal and external peak torques (PTs) of uninvolved and involved sides of EG were increased in EG after 12 weeks. Such results provide a deficit ratio of both sides in EG close to normal values. The ratios of internal/external PTs in EG were also close to the reference values. The internal and external total works of both sides in EG were similar to the values of PT. The fatigue indices of internal and external rotators of both sides in EG were decreased. As a conclusion, a 12-week rehabilitation program reduced the shoulder pain, improved the body composition and enhanced the isokinetic shoulder internal/external rotators in EG with impingement symptoms. Also the study suggested that the rehabilitation program evened out the ratio between internal and external rotators and lowered the fatigue level after the experiment. PMID:24678503

Can turned inward patella predict an excess of femoral anteversion during gait in spastic diplegic children?

PubMed

Simon, Anne-Laure; Presedo, Ana; Ilharreborde, Brice; Mallet, Cindy; Mazda, Keyvan; Penneçot, Georges-François

2014-06-01

Determining patellar orientation in the transverse plane during observational gait analysis is a fundamental aspect of physical examinations. Many physicians consider that an abnormal position of the patella in the transverse planes is only explained by a rotational abnormality of the proximal femur. A total of 188 spastic diplegic children with cerebral palsy were reviewed (376 lower limbs). The physical examination included observation of patellar orientation at midstride and measuring femoral anteversion (FA). All patients also underwent 3-dimensional (3D) computerized gait analysis of pelvic and hip rotation kinematics. Observational gait analysis and videotapes found 103 children (206 lower limbs) with inturned patella at midstance. Kinematic data from 3D gait analysis showed that the visual impression of turned inward patella was erroneous in 48 limbs. Of the remaining 158 lower limbs, 117 (74%) exhibited excessive FA and 41 (26%) did not. Of the 117 with excessive FA, kinematics showed only 66 (56%) with excessive internal hip rotation (with or without excessive internal pelvic rotation). Of the 41 lower limbs without excessive FA, 25 were explained by excessive internal pelvic rotation and 16 were explained by excessive internal hip rotation (isolated spasticity and/or contracture of internal rotator muscles). Turned inward patella was caused by isolated excessive internal pelvic rotation in 48%, excessive internal hip rotation in 35% (including 44 cases with excessive FA and 12 cases with isolated spasticity and/or contracture of internal hip rotators), and excessive internal hip rotation combined with excessive internal pelvic rotation in 17%. Excessive FA was not the only cause of turned inward patella gait and could not explain this gait anomaly by itself. Excessive internal pelvic rotation was the most frequent cause of turned inward patella gait. Level IV.

Rotating night shift work and physical activity of nurses and midwives in the cross-sectional study in Łódź, Poland.

PubMed

Peplonska, Beata; Bukowska, Agnieszka; Sobala, Wojciech

2014-12-01

Shift work have been thought to restrict participation in leisure time activities, but the knowledge about physical activity in rotating night shift nurses has been limited so far. We investigated the associations between the rotating night shift work and physical activity using data from a cross-sectional study among nurses and midwives. This study included 354 nurses and midwives (aged 40-60) currently working rotating night shifts and 371 ones working days only. The information on the work characteristics and potential covariates was collected via a personal interview. Weight and height were measured and BMI was calculated. Physical activity was assessed according to the international questionnaire on physical activity - IPAQ, and four domains: leisure time, occupational, transport related and household were analyzed. Women who reported none leisure time activity were defined as recreationally "inactive". The associations were examined with multiple linear or logistic regression models adjusted for age, season of the year, number of full term births, marital status and BMI. Total and occupational physical activity was significantly higher among nurses working rotating night shifts. However, leisure time activity was significantly affected among rotating night shift nurses and midwives, compared to women working during the days only, with increased odds ratio for recreational "inactivity" (OR = 1.57, 95% CI: 1.11-2.20). Rotating night shift work among nurses and midwives is associated with higher occupational physical activity but lower leisure time activity. Initiatives supporting exercising among night shift workers are recommended.

Autologous platelet gel and platelet-poor plasma reduce pain with total shoulder arthroplasty.

PubMed

Zavadil, Douglas P; Satterlee, C Craig; Costigan, Jaime M; Holt, David W; Shostrom, Valerie K

2007-09-01

The recovery of patients undergoing total shoulder arthroplasty (TSA) can be adversely affected by a number of complications. Autologous platelet gel (APG), produced by activating platelet-rich plasma (PRP), has been shown to improve hemostasis and wound healing and reduce infections in some surgical procedures. Activated platelet-poor plasma (PPP) has also been used as a hemostatic agent. This study examines the effects of APG and PPP treatment on TSA patients postoperatively. After Institutional Review Board (IRB) approval, 40 patients undergoing TSA at our institution were prospectively enrolled in our study. They were randomized into either a control (n = 20) or study (n = 20) group, with the study group receiving APG and PPP treatment. Preoperative demographic data, pre- and postoperative laboratory data, pain scores, pain medication, complications, pre- and postoperative range of motion measurements, and postoperative lengths of stay were recorded for each group. The preoperative internal rotation index was significantly higher in the control group compared with treatment patients (4.64 +/- 4.46 vs. 1.88 +/- 2.44, p < .05). The percent hemoglobin retained postoperatively was higher in the treatment group at 24 (84.54 +/- 5.32 vs. 79.87 +/- 8.73) and 72 hours (87.46 +/- 16.03 vs. 76.70 vs. 5.96), but neither difference reached statistical significance. The treatment group had significantly lower pain scores (p = .007) and total fentanyl requirements (p < .05) compared with control patients. The internal rotation index improvement factor (postoperative internal rotation index/preoperative internal rotation index) was significantly higher in the treatment group vs. the control group (p < .05). Although it did not reach statistical significance, the treatment group was discharged almost 9 hours earlier than the control group (64.44 +/- 15.23 vs. 73.39 +/- 15.37). APG and PPP treatment decreased pain and provided a greater increase in internal rotation measurements postoperatively.

Electromyographic analysis of trunk and hip muscles during resisted lateral band walking.

PubMed

Youdas, James W; Foley, Brooke M; Kruger, BreAnna L; Mangus, Jessica M; Tortorelli, Alis M; Madson, Timothy J; Hollman, John H

2013-02-01

The purpose of this study was to simultaneously quantify bilateral activation/recruitment levels (% maximum voluntary isometric contraction [MVIC]) for trunk and hip musculature on both moving and stance lower limbs during resisted lateral band walking. Differential electromyographic (EMG) activity was recorded in neutral, internal, and external hip rotation in 21 healthy participants. EMG signals were collected with DE-3.1 double-differential surface electrodes at a sampling frequency of 1,000 Hz during three consecutive lateral steps. Gluteus medius average EMG activation was greater (p = 0.001) for the stance limb (52 SD 18% MVIC) than moving limb (35 SD 16% MVIC). Gluteus maximus EMG activation was greater (p = 0.002) for the stance limb (19 SD 13% MVIC) than moving limb (13 SD 9% MVIC). Erector spinae activation was greater (p = 0.007) in hip internal rotation (30 SD 13% MVIC) than neutral rotation (26 SD 10% MVIC) and the moving limb (31 SD 15% MVIC) was greater (p = 0.039) than the stance limb (23 SD 11% MVIC). Gluteus medius and maximus muscle activation were greater on the stance limb than moving limb during resisted lateral band walking. Therefore, clinicians may wish to consider using the involved limb as the stance limb during resisted lateral band walking exercise.

Effect of power-assisted hand-rim wheelchair propulsion on shoulder load in experienced wheelchair users: A pilot study with an instrumented wheelchair.

PubMed

Kloosterman, Marieke G M; Buurke, Jaap H; de Vries, Wiebe; Van der Woude, Lucas H V; Rietman, Johan S

2015-10-01

This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an instrumented wheelchair on a treadmill while upper-extremity kinematic, kinetic and surface electromyographical data was collected during propulsion with and without power-assist. As a result during power-assisted propulsion the peak resultant force exerted at the hand-rim decreased and was performed with significantly less abduction and internal rotation at the shoulder. At shoulder level the anterior directed force and internal rotation and flexion moments decreased significantly. In addition, posterior and the minimal inferior directed forces and the external rotation moment significantly increased. The stroke angle decreased significantly, as did maximum shoulder flexion, extension, abduction and internal rotation. Stroke-frequency significantly increased. Muscle activation in the anterior deltoid and pectoralis major also decreased significantly. In conclusion, compared to hand-rim propulsion power-assisted propulsion seems effective in reducing potential risk factors of overuse injuries with the highest gain on decreased range of motion of the shoulder joint, lower peak propulsion force on the rim and reduced muscle activity. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Acute Effects of Foot Rotation in Healthy Adults during Running on Knee Moments and Lateral-Medial Shear Force

PubMed Central

Valenzuela, Kevin A.; Lynn, Scott K.; Noffal, Guillermo J.; Brown, Lee E.

2016-01-01

As runners age, the likelihood of developing osteoarthritis (OA) significantly increases as 10% of people 55+ have symptomatic knee OA while 70% of people 65+ have radiographic signs of knee OA. The lateral-medial shear force (LMF) and knee adduction moment (KAM) during gait have been associated with cartilage loading which can lead to OA. Foot rotation during gait has been shown to alter the LMF and KAM, however it has not been investigated in running. The purpose of this study was to investigate changes in the KAM and LMF with foot rotation during running. Twenty participants volunteered and performed five running trials in three randomized conditions (normal foot position [NORM], external rotation [EXT], and internal rotation [INT]) at a running speed of 3.35m·s-1 on a 20 meter runway. Kinematic and kinetic data were gathered using a 9-camera motion capture system and a force plate, respectively. Repeated measures ANOVAs determined differences between conditions. The KAM and LMF were lower in both EXT and INT conditions compared to the NORM, but there were no differences between EXT and INT conditions. The decreases in KAM and LMF in the EXT condition were expected and concur with past research in other activities. The reductions in the INT condition were unexpected and contradict the literature. This may indicate that participants are making mechanical compensations at other joints to reduce the KAM and LMF in this abnormal internal foot rotation condition. Key points External rotation of the foot during running reduced the loads on the medial compartment of the knee Internal rotation of the foot also reduced the medial loads, but is a more unnatural intervention External and internal rotation reduced the shear forces on the knee, which may help slow the degeneration of knee joint cartilage PMID:26957926

Hip rotation range of motion in sitting and prone positions in healthy Japanese adults

PubMed Central

Han, Heonsoo; Kubo, Akira; Kurosawa, Kazuo; Maruichi, Shizuka; Maruyama, Hitoshi

2015-01-01

[Purpose] The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions. [Subjects] The subjects included 151 students. [Methods] Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip rotation ROM was calculated by adding the measured values for external and internal rotations. [Results] Ipsilateral hip rotation ROM revealed significant differences between two positions for both left and right internal and external rotations. Hip rotation ROM was significantly higher in the prone position than in the sitting position. Hip rotation ROM significantly differed between the men and women. Hip external rotation ROM was significantly higher in both positions in men; conversely, hip internal rotation ROM was significantly higher in both positions in women. [Conclusion] Hip rotation ROM significantly differed between the sexes and between the sitting and prone positions. Total ipsilateral hip rotation ROM, total angle of external rotation, and total angle of internal rotation of the left and right hips greatly varied, suggesting that hip joint rotational ROM is widely distributed. PMID:25729186

Anatomical glenohumeral internal rotation deficit and symmetric rotational strength in male and female young beach volleyball players.

PubMed

Saccol, Michele Forgiarini; Almeida, Gabriel Peixoto Leão; de Souza, Vivian Lima

2016-08-01

Beach volleyball is a sport with a high demand of shoulder structures that may lead to adaptations in range of motion (ROM) and strength like in other overhead sports. Despite of these possible alterations, no study evaluated the shoulder adaptations in young beach volleyball athletes. The aim of this study was to compare the bilateral ROM and rotation strength in the shoulders of young beach volleyball players. Goniometric passive shoulder ROM of motion and isometric rotational strength were evaluated in 19 male and 14 female asymptomatic athletes. External and internal ROM, total rotation motion, glenohumeral internal rotation deficit (GIRD), external rotation and internal rotation strength, bilateral deficits and external rotation to internal rotation ratio were measured. The statistical analysis included paired Student's t-test and analysis of variance with repeated measures. Significantly lower dominant GIRD was found in both groups (p<0.05), but only 6 athletes presented pathological GIRD. For strength variables, no significant differences for external or internal rotation were evident. Young beach volleyball athletes present symmetric rotational strength and shoulder ROM rotational adaptations that can be considered as anatomical. These results indicate that young practitioners of beach volleyball are subject to moderate adaptations compared to those reported for other overhead sports. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stellar Rotation: New Insight from CoRoT

NASA Astrophysics Data System (ADS)

Catala, C.; Goupil, M. J.; Michel, E.; Baglin, A.; de Medeiros, J. Renan; Gondoin, Ph.

2009-02-01

We present an overview of the new insight provided by the CoRoT satellite on stellar rotation. Thanks to its ultra-high precision, high duty cycle, long photometric monitoring of thousands of stars, CoRoT gives us a powerful tool to study stellar rotational modulation, and therefore to measure stellar rotational periods and to study active structures at the surface of stars. This paper presents preliminary results concerning this type of study. CoRoT will also provide us with an insight of internal stellar rotation via the measurement and exploitation of rotational splittings of oscillation modes. This approach to stellar rotation with CoRoT will require a careful analysis of the oscillation power spectra, which is in progress, but prospects for such measurements are presented.

Humeral component retroversion in reverse total shoulder arthroplasty: a biomechanical study.

PubMed

Gulotta, Lawrence V; Choi, Dan; Marinello, Patrick; Knutson, Zakary; Lipman, Joseph; Wright, Timothy; Cordasco, Frank A; Craig, Edward V; Warren, Russell F

2012-09-01

Reverse total shoulder arthroplasty offers pain relief and functional improvement for patients with rotator cuff-deficient shoulders. The purpose of this study was to determine the optimal amount of humeral retroversion for this prosthesis. Six cadaveric shoulders underwent computed tomography (CT) imaging and were then dissected of soft tissues, except for their tendinous attachments. A reverse total shoulder arthroplasty was implanted in 0°, 20°, 30°, and 40° of retroversion, and the shoulders were mounted on a simulator to determine the muscle forces required to achieve 30° and 60° of scaption. CT images were converted into 3-dimensional models, and the amount of internal and external rotation was determined with computer modeling at various scaption angles. No differences were found in the forces required for 30° or 60° of scaption for any muscle, at any retroversion. With increasing retroversion, more impingement-free external rotation was obtained, with a concomitant decrease in the amount of internal rotation. Above 60°, the humerus was allowed to rotate around the glenosphere unencumbered. Increasing retroversion did not affect the muscle force requirements for scaption across the shoulder. Placing the humeral component in 0° to 20° of retroversion allows maximum internal rotation with the arm at the side, a movement that is required for daily activities. This limits external rotation with the arm at the side, but has no effect on external rotation with the arm elevated. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Rotational glenohumeral adaptations are associated with shoulder pathology in professional male handball players.

PubMed

Lubiatowski, Przemyslaw; Kaczmarek, Piotr; Cisowski, Pawel; Breborowicz, Ewa; Grygorowicz, Monika; Dzianach, Marcin; Krupecki, Tomasz; Laver, Lior; Romanowski, Leszek

2018-01-01

Glenohumeral range of motion adaptations may affect throwing athletes and contribute to shoulder injury. The purpose of this study was to evaluate shoulder rotation deficits among elite professional handball players and its correlation to the presence of shoulder pain and morphological changes. Eighty-seven elite professional handball players and 41 healthy non-athlete volunteers participated in the study. Evaluations included measurement of range of internal and external rotation, total arch of motion, identification of shoulder pain and ultrasound scan for diagnosis of rotator cuff tears and internal impingement. Glenohumeral rotational deficits (>20-25°) were found among 11 players group (13%). The throwing shoulders in the players group showed a decrease in internal rotation and an increase in external rotation with significantly larger ranges among players compared to the non-athlete group. Internal rotation deficit >20° was associated with higher incidence of shoulder pain among players. Both internal rotation deficits (>25°) and total arch of motion deficit (>20°) co-existed with higher incidence of internal impingement. Shoulder pain was common (36/97-41%) and was associated with decreased external rotation and total arch of motion. Internal impingement (found in 13/87-15%) correlated with decreased rotation ranges and a greater deficit in total arch of motion, whereas higher gain in external rotation correlated with a partial rotator cuff tear (found in 12/87-14%). Shoulder pathologies and problems commonly affected the group of handball players. Greater glenohumeral rotational deficits in throwing shoulders of handball players correlate with shoulder pain and internal impingement, while increased external rotation with partial rotator cuff tears. Such deficits affect 13% of the athlete population. Major clinical relevance of the study is to monitor handball players' shoulders both clinically and by proper imaging. Evaluation of range of rotation seems to identify shoulders at risk of the pathology. Cross-Sectional study with control group, Level II.

Glenohumeral joint translation and muscle activity in patients with symptomatic rotator cuff pathology: An ultrasonographic and electromyographic study with age-matched controls.

PubMed

Rathi, Sangeeta; Taylor, Nicholas F; Soo, Brendan; Green, Rodney A

2018-03-02

To determine whether patients with symptomatic rotator cuff pathology had more glenohumeral joint translation and different patterns of rotator cuff muscle activity compared to controls. Repeated measurements of glenohumeral translation and muscle activity in two positions and six testing conditions in two groups. Twenty participants with a symptomatic and diagnosed rotator cuff tear and 20 age, and gender matched controls were included. Neuromuscular activity was tested by inserting intramuscular electrodes in the rotator cuff muscles. Anterior and posterior glenohumeral translations were measured using real time ultrasound in testing conditions (with and without translation force, with and without isometric internal and external rotation), in two positions (shoulder neutral, 90° of abduction) and two force directions (anterior, posterior). Symptomatic pathology group demonstrated increased passive glenohumeral translation with posterior translation force (p<0.05). Overall, rotator cuff muscle contraction in the pathology group limited joint translation in a similar manner to the control group, but they did not show the normal direction specific pattern in the neutral posterior position (p<0.03). The pathology group demonstrated reduced EMG activity in the upper infraspinatus muscle relative to the reference position (p<0.02) with anterior translation force and in the supraspinatus (p<0.05) muscle with anterior and posterior translation force in the abducted position. Symptomatic pathology resulted in increased passive glenohumeral joint translation. Although there were some reductions in muscle activity with injury, their rotator cuff still controlled glenohumeral translation. These results highlight the need to consider joint translation in the assessment and management of patients with rotator cuff injury. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Using relative velocity vectors to reveal axial rotation about the medial and lateral compartment of the knee.

PubMed

Anderst, William J; Tashman, Scott

2010-03-22

A new technique is presented that utilizes relative velocity vectors between articulating surfaces to characterize internal/external rotation of the tibio-femoral joint during dynamic loading. Precise tibio-femoral motion was determined by tracking the movement of implanted tantalum beads in high-speed biplane X-rays. Three-dimensional, subject-specific CT reconstructions of the femur and tibia, consisting of triangular mesh elements, were positioned in each analyzed frame. The minimum distance between subchondral bone surfaces was recorded for each mesh element comprising each bone surface, and the relative velocity between these opposing closest surface elements was determined in each frame. Internal/external rotation was visualized by superimposing tangential relative velocity vectors onto bone surfaces at each instant. Rotation about medial and lateral compartments was quantified by calculating the angle between these tangential relative vectors within each compartment. Results acquired from 68 test sessions involving 23 dogs indicated a consistent pattern of sequential rotation about the lateral condyle (approximately 60 ms after paw strike) followed by rotation about the medial condyle (approximately 100 ms after paw strike). These results imply that axial knee rotation follows a repeatable pattern within and among subjects. This pattern involves rotation about both the lateral and medial compartments. The technique described can be easily applied to study human knee internal/external rotation during a variety of activities. This information may be useful to define normal and pathologic conditions, to confirm post-surgical restoration of knee mechanics, and to design more realistic prosthetic devices. Furthermore, analysis of joint arthrokinematics, such as those described, may identify changes in joint mechanics associated with joint degeneration. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Automatic toilet seat lowering apparatus

DOEpatents

Guerty, Harold G.

1994-09-06

A toilet seat lowering apparatus includes a housing defining an internal cavity for receiving water from the water supply line to the toilet holding tank. A descent delay assembly of the apparatus can include a stationary dam member and a rotating dam member for dividing the internal cavity into an inlet chamber and an outlet chamber and controlling the intake and evacuation of water in a delayed fashion. A descent initiator is activated when the internal cavity is filled with pressurized water and automatically begins the lowering of the toilet seat from its upright position, which lowering is also controlled by the descent delay assembly. In an alternative embodiment, the descent initiator and the descent delay assembly can be combined in a piston linked to the rotating dam member and provided with a water channel for creating a resisting pressure to the advancing piston and thereby slowing the associated descent of the toilet seat. A toilet seat lowering apparatus includes a housing defining an internal cavity for receiving water from the water supply line to the toilet holding tank. A descent delay assembly of the apparatus can include a stationary dam member and a rotating dam member for dividing the internal cavity into an inlet chamber and an outlet chamber and controlling the intake and evacuation of water in a delayed fashion. A descent initiator is activated when the internal cavity is filled with pressurized water and automatically begins the lowering of the toilet seat from its upright position, which lowering is also controlled by the descent delay assembly. In an alternative embodiment, the descent initiator and the descent delay assembly can be combined in a piston linked to the rotating dam member and provided with a water channel for creating a resisting pressure to the advancing piston and thereby slowing the associated descent of the toilet seat.

Differential activation of parts of the latissimus dorsi with various isometric shoulder exercises.

PubMed

Park, Se-yeon; Yoo, Won-gyu

2014-04-01

As no study has examined whether the branches of the latissimus dorsi are activated differently in different exercises, we investigated intramuscular differences of components of the latissimus dorsi during various shoulder isometric exercises. Seventeen male subjects performed four isometric exercises: shoulder extension, adduction, internal rotation, and shoulder depression. Surface electromyography (sEMG) was used to collect data from the medial and lateral components of the latissimus dorsi during the isometric exercises. Two-way repeated analysis of variance with two within-subject factors (exercise condition and muscle branch) was used to determine the significance of differences between the branches, and which branch was activated more with the exercise variation. The root mean squared sEMG values for the muscles were normalized using the modified isolation equation (%Isolation) and maximum voluntary isometric contraction (%MVIC). Neither the %MVIC nor %Isolation data differed significantly between muscle branches, while there was a significant difference with exercise. %MVIC was significantly higher with shoulder extension, compared to the other isometric exercises. There was a significant correlation between exercise condition and muscle branch in the %Isolation data. Shoulder extension and adduction and internal rotation increased %Isolation of the medial latissimus dorsi more than shoulder depression. Shoulder depression had the highest value of %Isolation of the lateral latissimus dorsi compared to the other isometric exercises. Comparing the medial and lateral latissimus dorsi, the medial component was predominantly activated with shoulder extension, adduction, and internal rotation, and the lateral component with shoulder depression. Shoulder extension is effective for activating the latissimus dorsi regardless of the intramuscular branch. Copyright © 2014 Elsevier Ltd. All rights reserved.

International Laser Ranging Service (ILRS): Terms of Reference

NASA Technical Reports Server (NTRS)

Husson, Van; Noll, Carey

2000-01-01

The International Laser Ranging Service (ILRS) is an established Service within Section II , Advanced Space Technology, of the International Association of Geodesy (IAG). The primary objective of the ILRS is to provide a service to support, through Satellite and Lunar Laser Ranging data and related products, geodetic and geophysical research activities as well as International Earth Rotation Service (IERS) products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). The service also develops the necessary standards/specifications and encourages international adherence to its conventions.

Angular velocity affects trunk muscle strength and EMG activation during isokinetic axial rotation.

PubMed

Fan, Jian-Zhong; Liu, Xia; Ni, Guo-Xin

2014-01-01

To evaluate trunk muscle strength and EMG activation during isokinetic axial rotation at different angular velocities. Twenty-four healthy young men performed isokinetic axial rotation in right and left directions at 30, 60, and 120 degrees per second angular velocity. Simultaneously, surface EMG was recorded on external oblique (EO), internal oblique (IO), and latissimus dorsi (LD) bilaterally. In each direction, with the increase of angular velocity, peak torque decreased, whereas peak power increased. During isokinetic axial rotation, contralateral EO as well as ipsilateral IO and LD acted as primary agonists, whereas, ipsilateral EO as well as contralateral IO and LD acted as primary antagonistic muscles. For each primary agonist, the root mean square values decreased with the increase of angular velocity. Antagonist coactiviation was observed at each velocity; however, it appears to be higher with the increase of angular velocity. Our results suggest that velocity of rotation has great impact on the axial rotation torque and EMG activity. An inverse relationship of angular velocity was suggested with the axial rotation torque as well as root mean square value of individual trunk muscle. In addition, higher velocity is associated with higher coactivation of antagonist, leading to a decrease in torque with the increase of velocity.

Rotational characterization of methyl methacrylate: Internal dynamics and structure determination

NASA Astrophysics Data System (ADS)

Herbers, Sven; Wachsmuth, Dennis; Obenchain, Daniel A.; Grabow, Jens-Uwe

2018-01-01

Rotational constants, Watson's S centrifugal distortion coefficients, and internal rotation parameters of the two most stable conformers of methyl methacrylate were retrieved from the microwave spectrum. Splittings of rotational energy levels were caused by two non equivalent methyl tops. Constraining the centrifugal distortion coefficients and internal rotation parameters to the values of the main isotopologues, the rotational constants of all single substituted 13C and 18O isotopologues were determined. From these rotational constants the substitution structures and semi-empirical zero point structures of both conformers were precisely determined.

Differential Rotation in Sun-like Stars from Surface Variability and Asteroseismology

NASA Astrophysics Data System (ADS)

Nielsen, Martin Bo

2017-03-01

The Sun and other stars are known to oscillate. Through the study of small perturbations to the frequencies of these oscillations the rotation of the deep interior can be inferred. However, thus far the internal rotation of other Sun-like stars is unknown. The NASA Kepler mission has observed a multitude of Sun-like stars over a period of four years. This has provided high-quality photometric data that can be used to study the rotation of stars with two different techniques: asteroseismology and surface activity. Asteroseismology provides a means of measuring rotation in the stellar interior, while photometric variability from magnetically active regions are sensitive to rotation at the stellar surface. The combination of these two methods can be used to constrain the radial differential rotation in Sun-like stars. First, we developed an automated method for measuring the rotation of stars using surface variability. This method was initially applied to the entire Kepler catalog, out of which we detected signatures of rotation in 12,000 stars across the main sequence, providing robust estimates of the surface rotation rates and the associated errors. Second, we performed an asteroseismic analysis of six Sun-like stars, where we were able to measure the rotational splitting as a function of frequency in the p-mode envelope. This was done by dividing the oscillation spectrum into individual segments, and fitting a model independently to each segment. We found that the measured splittings were all consistent with a constant value, indicating little differential rotation. Third, we compared the asteroseismic rotation rates of five Sun-like stars to their surface rotation rates. We found that the values were in good agreement, again indicating little differential rotation between the regions where the two methods are most sensitive. Finally, we discuss how the surface rotation rates may be used as a prior on the seismic envelope rotation rate in a double-zone model, consisting of an independently-rotating radiative interior and convective envelope. Using such a prior we find that the rotation rates of the radiative interior and convective envelope likely do not differ by more than 50%. This further supports the idea that Sun-like stars likely show a rotation pattern similar to that of the Sun. Results from the analysis presented herein provide physical limits on the internal differential rotation of Sun-like stars, and show that this method may be easily applied to a wider variety of stars.

Preoperative hip rotation moments do not predict long-term development after femoral derotation osteotomy in children with cerebral palsy.

PubMed

Braatz, Frank; Dreher, Thomas; Wolf, Sebastian I; Niklasch, Mirjam

2018-03-01

Femoral derotation osteotomy (FDO) is the standard treatment for internal rotation gait (IRG) in children with cerebral palsy (CP) although high rates of recurrence have been reported recently. Various factors associated with recurrence could be identified, but no predictor named. Does FDO lead to a change of internal transversal hip moments? Are preoperative internal transversal hip moments a predictor for recurrence of IRG? 41 children with spastic bilateral CP and 72 limbs that received a FDO (10.4 ± 2.7 years at surgery) were included retrospectively. Kinematic data were analyzed pre- (2 ± 3 months), postoperatively (12 ± 3 months) and at long-term follow-up (at least five years postoperatively; 84 ± 13 months), internal transversal hip moments were analyzed pre- and postoperatively. The maximum peaks of the internal hip rotation moment during loading response decreased significantly (p = 0.003). The minimum during the second half of the stance phase increased significantly (p = 0.004) and the initially internal externally rotating moment changed to an internal internally rotating moment. No correlation between changes in hip rotation from postoperatively to the long-term follow-up and the preoperative internal hip rotation moment could be identified. FDO leads to changes in internal hip rotation moments. Preoperative internal hip rotation moments can't be used as predicting factor for recurrence of IRG. The data suggest, that recurrence of IRG depends less on patient specific motion patterns, but more on the time point of surgery and the therapy of all concomitant deformities during SEMLS. Copyright © 2018 Elsevier B.V. All rights reserved.

Which shoulder motions cause subacromial impingement? Evaluating the vertical displacement and peak strain of the coracoacromial ligament by ultrasound speckle tracking imaging.

PubMed

Park, In; Lee, Hyo-Jin; Kim, Sung-Eun; Bae, Sung-Ho; Byun, Chu-Hwan; Kim, Yang-Soo

2015-11-01

Subacromial impingement is a common cause of shoulder pain and one cause of rotator cuff disease. We aimed to identify which shoulder motions cause subacromial impingement by measuring the vertical displacement and peak strain of the coracoacromial ligament using ultrasound speckle tracking imaging. Sixteen shoulders without shoulder disability were enrolled. All subjects were men, and the average age was 28.6 years. The vertical displacement and peak strain of the coracoacromial ligament were analyzed by the motion tracing program during the following active assisted motions (active motion controlled by the examiner): (1) forward flexion in the scapular plane, (2) horizontal abduction in the axial plane, (3) external rotation with the arm at 0° abduction (ER0), (4) internal rotation with the arm at 0° abduction (IR0), (5) internal rotation with the arm at 90° abduction (IR90), and (6) internal rotation at the back (IRB). The mean vertical displacement of the coracoacromial ligament during forward flexion (2.2 mm), horizontal abduction (2.2 mm), and IR90 (2.4 mm) was significantly greater than that during the other motions (ER0, -0.7 mm; IR0, 0.5 mm; IRB, 1.0 mm; P < .003). The mean peak strain was significantly higher in forward flexion (6.88%), horizontal abduction (6.58%), and IR90 (4.88%) than with the other motions (ER0, 1.42%; IR0, 1.78%; IRB, 2.61%; P < .003). Forward flexion, horizontal abduction, and IR90 showed higher vertical displacement and peak strain of the coracoacromial ligament, causing subacromial impingement. It is recommended that patients with impingement syndrome or a repaired rotator cuff avoid these shoulder motions. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

In Vivo Talocrural Joint Contact Mechanics With Functional Ankle Instability.

PubMed

Kobayashi, Takumi; Suzuki, Eiichi; Yamazaki, Naohito; Suzukawa, Makoto; Akaike, Atsushi; Shimizu, Kuniaki; Gamada, Kazuyoshi

2015-12-01

Functional ankle instability (FAI) may involve abnormal kinematics and contact mechanics during ankle internal rotation. Understanding of these abnormalities is important to prevent secondary problems in patients with FAI. However, there are no in vivo studies that have investigated talocrural joint contact mechanics during weightbearing ankle internal rotation. The objective of this study to determine talocrural contact mechanics during weightbearing ankle internal rotation in patients with FAI. Twelve male subjects with unilateral FAI (age range, 18-26 years) were enrolled. Computed tomography and fluoroscopic imaging of both lower extremities were obtained during weightbearing passive ankle joint complex rotation. Three-dimensional bone models created from the computed tomographic images were matched to the fluoroscopic images to compute 6 degrees of freedom for talocrural joint kinematics. The closest contact area in the talocrural joint in ankle neutral rotation and maximum internal rotation during either dorsiflexion or plantar flexion was determined using geometric bone models and talocrural joint kinematics data. The closest contact area in the talus shifted anteromedially during ankle dorsiflexion-internal rotation, whereas it shifted posteromedially during ankle plantar flexion-internal rotation. The closest contact area in FAI joints was significantly more medial than that in healthy joints during maximum ankle internal rotation and was associated with excessive talocrural internal rotation or inversion. This study demonstrated abnormal talocrural kinematics and contact mechanics in FAI subjects. Such abnormal kinematics may contribute to abnormal contact mechanics and may increase cartilage stress in FAI joints. Therapeutic, Level IV: cross-sectional case-control study. © 2015 The Author(s).

Functional magnetic resonance imaging examination of two modular architectures for switching multiple internal models.

PubMed

Imamizu, Hiroshi; Kuroda, Tomoe; Yoshioka, Toshinori; Kawato, Mitsuo

2004-02-04

An internal model is a neural mechanism that can mimic the input-output properties of a controlled object such as a tool. Recent research interests have moved on to how multiple internal models are learned and switched under a given context of behavior. Two representative computational models for task switching propose distinct neural mechanisms, thus predicting different brain activity patterns in the switching of internal models. In one model, called the mixture-of-experts architecture, switching is commanded by a single executive called a "gating network," which is different from the internal models. In the other model, called the MOSAIC (MOdular Selection And Identification for Control), the internal models themselves play crucial roles in switching. Consequently, the mixture-of-experts model predicts that neural activities related to switching and internal models can be temporally and spatially segregated, whereas the MOSAIC model predicts that they are closely intermingled. Here, we directly examined the two predictions by analyzing functional magnetic resonance imaging activities during the switching of one common tool (an ordinary computer mouse) and two novel tools: a rotated mouse, the cursor of which appears in a rotated position, and a velocity mouse, the cursor velocity of which is proportional to the mouse position. The switching and internal model activities temporally and spatially overlapped each other in the cerebellum and in the parietal cortex, whereas the overlap was very small in the frontal cortex. These results suggest that switching mechanisms in the frontal cortex can be explained by the mixture-of-experts architecture, whereas those in the cerebellum and the parietal cortex are explained by the MOSAIC model.

Incorporation of a Global Surgery Rotation into an Academic General Surgery Residency Program: Impact and Perceptions.

PubMed

LeCompte, Michael Thomas; Goldman, Connor; Tarpley, John L; Tarpley, Margaret; Hansen, Erik N; Nthumba, Peter M; Terhune, Kyla P; Kauffmann, Rondi M

2018-03-14

Global surgery is increasingly recognized as a vital component of international public health. Access to basic surgical care is limited in much of the world, resulting in a global burden of treatable disease. To address the lack of surgical workforce in underserved environments and to foster ongoing interest in global health among US-trained surgeons, our institution established a residency rotation through partnership with an academic hospital in Kijabe, Kenya. This study evaluates the perceptions of residents involved in the rotation, as well as its impact on their future involvement in global health. A retrospective review of admission applications from residents matriculating at our institution was conducted to determine stated interest in global surgery. These were compared to post-rotation evaluations and follow-up surveys to assess interest in global surgery and the effects of the rotation on the practices of the participants. A total of 78 residents matriculated from 2006 to 2016. Seventeen participated in the rotation with 76% of these reporting high satisfaction with the rotation. Sixty-five percent had no prior experience providing health care in an international setting. Post-rotation surveys revealed an increase in global surgery interest among participants. Long-term interest was demonstrated in 33% (n = 6) who reported ongoing activity in global health in their current practices. Participation in global rotations was also associated with increased interest in domestically underserved populations and affected economic and cost decisions within graduates' practices.

Immobilization in Neutral Rotation for a Glenohumeral Dislocation Using a Sling and Splint

PubMed Central

2008-01-01

The purpose of this manuscript is to provide an expedient means of immobilizing a glenohumeral dislocation in neutral rotation. This technique for post-reduction immobilization of a glenohumeral dislocation is inexpensive and easy to fabricate. Anterior glenohumeral dislocations often involve an avulsion of the labrum from the glenoid rim. In contrast to immobilization in internal rotation, positioning the shoulder in 0-45° of external rotation approximates the labrum and glenoid rim. It is hypothesized that placing the shoulder in a more externally rotated position could allow for better healing and increased joint stability. This technique places the shoulder in neutral rotation, because 45° of external rotation is awkward and may interfere with certain activities of daily living. Structural aluminum malleable (SAM) splints are used as an alternative to a bolster sling. The SAM splints are lightweight, simply shaped, and easily stored. PMID:21509136

Effects of 6-week sling-based training of the external-rotator muscles on the shoulder profile in elite female high school handball players.

PubMed

Genevois, Cyril; Berthier, Philippe; Guidou, Vincent; Muller, Franck; Thiebault, Boris; Rogowski, Isabelle

2014-11-01

In women's handball, the large numbers of throws and passes make the shoulder region vulnerable to overuse injuries. Repetitive throwing motions generate imbalance between shoulder internal- and external-rotator muscles. It has not yet been established whether sling-based training can improve shoulder external-rotator muscle strength. This study investigated the effectiveness of a 6-wk strengthening program in improving shoulder functional profile in elite female high school handball players. Crossover study. National elite handball training center. 25 elite female high school handball players. The program, completed twice per week for 6 wk, included sling-based strengthening exercises using a suspension trainer for external rotation with scapular retraction and scapular retraction alone. Maximal shoulder external- and internal-rotation strength, shoulder external- and internal-rotation range of motion (ROM), and maximal throwing velocity were assessed preintervention and postintervention for dominant and nondominant sides. After sling training, external- and internal-rotation strength increased significantly for both sides (P ≤ .001, and P = .004, respectively), with the result that there was no significant change in external- and internal-rotation strength ratios for either the dominant or the nondominant shoulder. No significant differences were observed for external-rotation ROM, while internal-rotation ROM decreased moderately, in particular in the dominant shoulder (P = .005). Maximal throwing velocity remained constant for the dominant arm, whereas a significant increase was found for the nondominant arm (P = .017). This 6-wk strengthening program was effective in improving shoulder external-rotator muscle strength but resulted in a decrease in the ROM in shoulder internal rotation, while throwing velocity remained stable. Adding a stretching program to this type of sling-based training program might help avoid potential detrimental effects on shoulder ROM.

EFFECT OF CHERENKOV LIGHT POLARIZATION ON TOTAL REFLECTION COUNTER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dowell, J.D.; Duteil, P.; Leontic, B.

1963-01-01

A rugged total internal reflection counter with a 3- to 5cm thick compact radiator was used at the CERN proton synchrotron for beam analysis. The threshold behavior of this counter was compared when filled with glycerol and with turpentine. Turpentine is optically active and rotates the plane of polarization about 7 un. Concent 85% /cm. Figures illustrate the effect of this polarization rotation. (A.G.W.)

Which is the best predictor of excessive hip internal rotation in women with patellofemoral pain: Rearfoot eversion or hip muscle strength? Exploring subgroups.

PubMed

Ferreira, Amanda Schenatto; de Oliveira Silva, Danilo; Briani, Ronaldo Valdir; Ferrari, Deisi; Aragão, Fernando Amâncio; Pazzinatto, Marcella Ferraz; de Azevedo, Fábio Mícolis

2018-03-26

Patellofemoral pain (PFP) has been linked to increased patellofemoral joint stress as a result of excessive hip internal rotation. Lower hip strength and/or excessive rearfoot eversion have been used to explain such altered movement pattern; however, it is unknown which one is the best predictor of excessive hip internal rotation. To investigate if peak rearfoot eversion and/or peak concentric hip abductor strength can predict peak hip internal rotation during stair ascent in women with PFP. This cross-sectional study included thirty-seven women with PFP which underwent three-dimensional kinematic analysis during stair ascent and hip abductor strength analysis in an isokinetic dynamometer. A forced entry linear regression model analysis was carried out to determine which independent variables present the best capability to predict the hip internal rotation. Peak concentric hip abductor strength significantly predicted peak hip internal rotation during stair ascent (R 2  = 0.27, p = 0.001). Peak rearfoot eversion did not predict peak hip internal rotation during stair ascent (R 2  < 0.01, p = 0.62). A Post-hoc analysis was conducted to explore if a subgroup with excessive rearfoot eversion would predict hip internal rotation. Based on a previous reported cut-off point, 48.6% of the participants were classified as excessive rearfoot eversion. For the subgroup with excessive rearfoot eversion, peak concentric hip abductor strength and peak rearfoot eversion significantly predicted peak hip internal rotation during stair ascent (R 2  = 0.26, p = 0.02; R 2  = 0.42, p = 0.003, respectively). For non-excessive rearfoot eversion subgroup, peak concentric hip abductor strength significantly predicted peak hip internal rotation during stair ascent (R 2  = 0.53; p < 0.001); and peak rearfoot eversion did not (R 2  = 0.01; p = 0.65). Findings indicate that hip muscle strength seems to be related with hip internal rotation in all women with PFP. Rearfoot eversion seems to be related with hip internal rotation only in a subgroup with excessive rearfoot eversion. Copyright © 2018. Published by Elsevier B.V.

Influence of Component Rotation in Total Knee Arthroplasty on Tibiofemoral Kinematics-A Cadaveric Investigation.

PubMed

Maderbacher, Guenther; Keshmiri, Armin; Springorum, Hans R; Maderbacher, Hermann; Grifka, Joachim; Baier, Clemens

2017-09-01

Physiological tibiofemoral kinematics have been shown to be important for good knee function after total knee arthroplasty (TKA). The purpose of the present study was to investigate the influence of component rotation on tibiofemoral kinematics during knee flexion. We asked which axial component alignment best reconstructs physiological tibiofemoral kinematics and which combinations should be avoided. Ten healthy cadaveric knees were examined. By means of a navigational device, tibiofemoral kinematics between 0° and 90° of flexion were assessed before and after TKA using the following different rotational component alignment: femoral components: ligament balanced, 6° internal, 3° external rotation, and 6° external rotation in relation to the posterior condylar line; tibial components: self-adapted, 6° internal rotation, and 6° external rotation. Physiological tibiofemoral kinematics could be partly reconstructed by TKA. Ligament-balanced femoral rotation and 6° femoral external rotation both in combination with 6° tibial component external rotation, and 3° femoral external rotation in combination with 6° tibial component internal rotation or self-aligning tibial component were able to restore tibial longitudinal rotation. Largest kinematical differences were found for the combination femoral component internal and tibial component external rotations. From a kinematic-based view, surgeons should avoid internal rotation of femoral components. However, even often recommended combinations of rotational component alignment (3° femoral external and tibial external rotation) significantly change tibiofemoral kinematics. Self-aligning tibial components solely restored tibiofemoral kinematics with the combination of 3° femoral component of external rotation. For the future, navigational devices might help to axially align components to restore patient-specific and natural tibiofemoral kinematics. Copyright © 2017 Elsevier Inc. All rights reserved.

The functional significance of velocity storage and its dependence on gravity.

PubMed

Laurens, Jean; Angelaki, Dora E

2011-05-01

Research in the vestibular field has revealed the existence of a central process, called 'velocity storage', that is activated by both visual and vestibular rotation cues and is modified by gravity, but whose functional relevance during natural motion has often been questioned. In this review, we explore spatial orientation in the context of a Bayesian model of vestibular information processing. In this framework, deficiencies/ambiguities in the peripheral vestibular sensors are compensated for by central processing to more accurately estimate rotation velocity, orientation relative to gravity, and inertial motion. First, an inverse model of semicircular canal dynamics is used to reconstruct rotation velocity by integrating canal signals over time. However, its low-frequency bandwidth is limited to avoid accumulation of noise in the integrator. A second internal model uses this reconstructed rotation velocity to compute an internal estimate of tilt and inertial acceleration. The bandwidth of this second internal model is also restricted at low frequencies to avoid noise accumulation and drift of the tilt/translation estimator over time. As a result, low-frequency translation can be erroneously misinterpreted as tilt. The time constants of these two integrators (internal models) can be conceptualized as two Bayesian priors of zero rotation velocity and zero linear acceleration, respectively. The model replicates empirical observations like 'velocity storage' and 'frequency segregation' and explains spatial orientation (e.g., 'somatogravic') illusions. Importantly, the functional significance of this network, including velocity storage, is found during short-lasting, natural head movements, rather than at low frequencies with which it has been traditionally studied.

The functional significance of velocity storage and its dependence on gravity

PubMed Central

Laurens, Jean

2013-01-01

Research in the vestibular field has revealed the existence of a central process, called ‘velocity storage’, that is activated by both visual and vestibular rotation cues and is modified by gravity, but whose functional relevance during natural motion has often been questioned. In this review, we explore spatial orientation in the context of a Bayesian model of vestibular information processing. In this framework, deficiencies/ambiguities in the peripheral vestibular sensors are compensated for by central processing to more accurately estimate rotation velocity, orientation relative to gravity, and inertial motion. First, an inverse model of semicircular canal dynamics is used to reconstruct rotation velocity by integrating canal signals over time. However, its low-frequency bandwidth is limited to avoid accumulation of noise in the integrator. A second internal model uses this reconstructed rotation velocity to compute an internal estimate of tilt and inertial acceleration. The bandwidth of this second internal model is also restricted at low frequencies to avoid noise accumulation and drift of the tilt/translation estimator over time. As a result, low-frequency translation can be erroneously misinterpreted as tilt. The time constants of these two integrators (internal models) can be conceptualized as two Bayesian priors of zero rotation velocity and zero linear acceleration, respectively. The model replicates empirical observations like ‘velocity storage’ and ‘frequency segregation’ and explains spatial orientation (e.g., ‘somatogravic’) illusions. Importantly, the functional significance of this network, including velocity storage, is found during short-lasting, natural head movements, rather than at low frequencies with which it has been traditionally studied. PMID:21293850

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, N. B.; Qu, Z. N., E-mail: znqu@ynao.ac.cn

The ensemble empirical mode decomposition (EEMD) analysis is utilized to extract the intrinsic mode functions (IMFs) of the solar mean magnetic field (SMMF) observed at the Wilcox Solar Observatory of Stanford University from 1975 to 2014, and then we analyze the periods of these IMFs as well as the relation of IMFs (SMMF) with some solar activity indices. The two special rotation cycles of 26.6 and 28.5 days should be derived from different magnetic flux elements in the SMMF. The rotation cycle of the weak magnetic flux element in the SMMF is 26.6 days, while the rotation cycle of themore » strong magnetic flux element in the SMMF is 28.5 days. The two rotation periods of the structure of the interplanetary magnetic field near the ecliptic plane are essentially related to weak and strong magnetic flux elements in the SMMF, respectively. The rotation cycle of weak magnetic flux in the SMMF did not vary over the last 40 years because the weak magnetic flux element derived from the weak magnetic activity on the full disk is not influenced by latitudinal migration. Neither the internal rotation of the Sun nor the solar magnetic activity on the disk (including the solar polar fields) causes the annual variation of SMMF. The variation of SMMF at timescales of a solar cycle is more related to weak magnetic activity on the full solar disk.« less

At the Cosmonaut Hotel in Baikonur, Kazakhstan, Expedition 48-49 crewmember Kate Rubins of NASA takes a spin in a rotating chair to test her vestibular system June 30 as part of pre-launch activities. Rubins, Anatoly Ivanishin of Roscosmos and Takuya Onishi of the Japan Aerospace Exploration Agency will launch July 7, Baikonur time, on the Soyuz MS-01 spacecraft for a planned four-month mission on the International Space Station...NASA/Alexander Vysotsky.

NASA Image and Video Library

2016-06-30

At the Cosmonaut Hotel in Baikonur, Kazakhstan, Expedition 48-49 crewmember Kate Rubins of NASA takes a spin in a rotating chair to test her vestibular system June 30 as part of pre-launch activities. Rubins, Anatoly Ivanishin of Roscosmos and Takuya Onishi of the Japan Aerospace Exploration Agency will launch July 7, Baikonur time, on the Soyuz MS-01 spacecraft for a planned four-month mission on the International Space Station. NASA/Alexander Vysotsky

At the Cosmonaut Hotel in Baikonur, Kazakhstan, Expedition 48-49 crewmember Takuya Onishi of the Japan Aerospace Exploration Agency takes a spin in a rotating chair to test his vestibular system June 30 as part of pre-launch activities. Onishi, Kate Rubins of NASA and Anatoly Ivanishin of Roscosmos will launch July 7, Baikonur time, on the Soyuz MS-01 spacecraft for a planned four-month mission on the International Space Station...NASA/Alexander Vysotsky.

NASA Image and Video Library

2016-06-30

At the Cosmonaut Hotel in Baikonur, Kazakhstan, Expedition 48-49 crewmember Takuya Onishi of the Japan Aerospace Exploration Agency takes a spin in a rotating chair to test his vestibular system June 30 as part of pre-launch activities. Onishi, Kate Rubins of NASA and Anatoly Ivanishin of Roscosmos will launch July 7, Baikonur time, on the Soyuz MS-01 spacecraft for a planned four-month mission on the International Space Station. NASA/Alexander Vysotsky

Gender differences in rotation of the shank during single-legged drop landing and its relation to rotational muscle strength of the knee.

PubMed

Kiriyama, Shinya; Sato, Haruhiko; Takahira, Naonobu

2009-01-01

Increased shank rotation during landing has been considered to be one of the factors for noncontact anterior cruciate ligament injuries in female athletes. There have been no known gender differences in rotational knee muscle strength, which is expected to inhibit exaggerated shank rotation. Women have less knee external rotator strength than do men. Lower external rotator strength is associated with increased internal shank rotation at the time of landing. Controlled laboratory study. One hundred sixty-nine healthy young subjects (81 female and 88 male; age, 17.0 +/- 1.0 years) volunteered to participate in this study. The subjects performed single-legged drop landings from a 20-cm height. Femoral and shank kinematics were measured using a 3D optoelectronic tracking system during the drop landings, and then the joint angles around the knee (flexion/extension, valgus/varus, and internal/external rotation) were calculated. The maximal isometric rotational muscle strength of the knee was measured at 30 degrees of knee flexion in a supine position using a dynamometer. The female subjects had significantly less external shank rotation strength than did the male subjects (P < .001). Female subjects also exhibited significantly greater peak shank internal rotation angles than did males during landing (P < .05). Moderate but significant association was found between the maximum shank external rotation strength and the peak shank internal rotation angle during landing (r = -0.322, P < .01). Female subjects tended to have poor shank external rotator strength. This may lead to large shank internal rotation movement during the single-legged drop landing. Improving strength training of the external rotator muscle may help decrease the rates of anterior cruciate ligament injury in female athletes.

Rotator cuff strength in recurrent anterior shoulder instability.

PubMed

Edouard, Pascal; Degache, Francis; Beguin, Laurent; Samozino, Pierre; Gresta, Giorgio; Fayolle-Minon, Isabelle; Farizon, Frédéric; Calmels, Paul

2011-04-20

Although rotator-cuff muscle contraction plays an important role in stabilizing the glenohumeral joint, little is known about the role of these muscles in the pathophysiology of recurrent anterior instability. We intended to analyze the association between isokinetic internal rotator and external rotator muscle strength and glenohumeral joint instability in patients with recurrent anterior instability that was not previously treated surgically. We enrolled thirty-seven patients with unilateral recurrent anterior posttraumatic shoulder dislocation and eleven healthy nonathletic subjects in this controlled study. The association between internal rotator and external rotator strength and shoulder instability was analyzed by side-to-side comparisons and comparisons with a control group. Isokinetic internal rotator and external rotator strength was evaluated with a Con-Trex dynamometer, with the subject seated and the shoulder abducted 45° in the scapular plane. Tests were performed at 180°/s, 120°/s, and 60°/s in concentric mode for both sides. Peak torque normalized to body weight and external rotator to internal rotator ratio were calculated for each angular velocity. Clinical and isokinetic evaluation was done by the same rehabilitation physician. The association between shoulder instability and internal rotator and external rotator strength was associated with side-to-side differences (p < 0.05). Compared with a control group, strength values were lower on the pathological shoulder side of the patients with shoulder instability than on the healthy contralateral shoulder of control subjects at 180°/s and 120°/s (p < 0.05). The side-to-side differences were increased when the nondominant upper-extremity side was involved and were decreased when the dominant side was involved. There was no association between glenohumeral joint instability and external rotator to internal rotator ratio. Internal rotator and external rotator weakness was associated with recurrent anterior instability, and side-to-side differences depended on the side of hand dominance. Use of a control group may help in the analysis of the influence of constraints on shoulder strength. Further prospective studies are necessary to determine whether the weakness is a cause or an effect of the instability.

Patch-Augmented Latissimus Dorsi Transfer and Open Reduction–Internal Fixation of Unstable Os Acromiale for Irreparable Massive Posterosuperior Rotator Cuff Tear

PubMed Central

Petri, Maximilian; Greenspoon, Joshua A.; Bhatia, Sanjeev; Millett, Peter J.

2015-01-01

Latissimus dorsi transfer is a reasonable treatment option for massive posterosuperior rotator cuff tears that can substantially improve chronically painful and dysfunctional shoulders. This report and accompanying video describe the treatment of an active 43-year-old man with severe pain and weakness in the right shoulder after 3 failed rotator cuff repairs. Preoperative imaging showed a massive posterosuperior rotator cuff tear retracted to the glenoid as well as a hypermobile os acromiale likely causing dynamic impingement and recurrent rotator cuff tears. After diagnostic arthroscopy, the latissimus tendon is harvested and augmented with a 3-mm human acellular dermal patch (ArthroFlex; Arthrex, Naples, FL). The native rotator cuff tissue is repaired as much as possible, and the latissimus tendon is passed underneath the deltoid and posterior to the teres minor. The patch-augmented tendon is then integrated into a double-row SpeedBridge repair of eight 4.75-mm BioComposite SwiveLock anchors (Arthrex). The bony surface of the os acromiale is prepared and then fixed to the acromion with 2 cannulated partially threaded screws and additional tension-band wiring. Postoperative rehabilitation initially focuses on early passive range of motion, followed by active and active-assisted motion and a biofeedback program starting at 6 weeks postoperatively. PMID:26697309

Rotational Spectrum of 1,1-Difluoroethane: Internal Rotation Analysis and Structure

NASA Astrophysics Data System (ADS)

Villamanan, R. M.; Chen, W. D.; Wlodarczak, G.; Demaison, J.; Lesarri, A. G.; Lopez, J. C.; Alonso, J. L.

1995-05-01

The rotational spectrum of CH3CHF2 in its ground state was measured up to 653 GHz. Accurate rotational and centrifugal distortion constants were determined. The internal rotation splittings were analyzed using the internal axis method. An ab initio structure has been calculated and a near-equilibrium structure has been estimated using offsets derived empirically. This structure was compared to an experimental r0 structure. The four lowest excited states (including the methyl torsion) have also been assigned.

Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

PubMed Central

Pontaga, Inese; Zidens, Janis

2014-01-01

The aim of the investigation was to: 1) compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2) determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15-year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg). The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external– concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles. PMID:25414738

The Goal of the IAU/IAG Joint Working Group on the Theory of Earth Rotation

NASA Technical Reports Server (NTRS)

Ferrandiz, J. M.; Gross, R. S.

2013-01-01

In 2012 the International Association of Geodesy (IAG) and the International Astronomical Union (IAU) initiated a process to establish a Joint Working Group (JWG) on theory of Earth rotation with the purpose of promoting the development of improved theories of the Earth rotation which reach the accuracy required to meet the needs of the near future as recommended by, e.g. GGOS, the Global Geodetic Observing System of the IAG. The JWG was approved by both organizations in April 2013 with the chairs being the two authors of this paper. Its structure comprises three Sub Working Groups (SWGs) addressing Precession/Nutation, Polar Motion and UT1, the Numerical Solutions and Validation, respectively. The SWGs should work in parallel for the sake of efficiency, but should keep consistency as an overall goal. This paper offers a view of the objectives and scope of the JWG and reports about its initial activities and plans.

Predicting the Functional Roles of Knee Joint Muscles from Internal Joint Moments.

PubMed

Flaxman, Teresa E; Alkjær, Tine; Simonsen, Erik B; Krogsgaard, Michael R; Benoit, Daniel L

2017-03-01

Knee muscles are commonly labeled as flexors or extensors and aptly stabilize the knee against sagittal plane loads. However, how these muscles stabilize the knee against adduction-abduction and rotational loads remains unclear. Our study sought 1) to classify muscle roles as they relate to joint stability by quantifying the relationship between individual muscle activation patterns and internal net joint moments in all three loading planes and 2) to determine whether these roles change with increasing force levels. A standing isometric force matching protocol required subjects to modulate ground reaction forces to elicit various combinations and magnitudes of sagittal, frontal, and transverse internal joint moments. Surface EMG measured activities of 10 lower limb muscles. Partial least squares regressions determined which internal moment(s) were significantly related to the activation of individual muscles. Rectus femoris and tensor fasciae latae were classified as moment actuators for knee extension and hip flexion. Hamstrings were classified as moment actuators for hip extension and knee flexion. Gastrocnemius and hamstring muscles were classified as specific joint stabilizers for knee rotation. Vastii were classified as general joint stabilizers because activation was independent of moment generation. Muscle roles did not change with increasing effort levels. Our findings indicate muscle activation is not dependent on anatomical orientation but perhaps on its role in maintaining knee joint stability in the frontal and transverse loading planes. This is useful for delineating the roles of biarticular knee joint muscles and could have implications in robotics, musculoskeletal modeling, sports sciences, and rehabilitation.

REVIEWS OF TOPICAL PROBLEMS: The differential rotation of stars

NASA Astrophysics Data System (ADS)

Kitchatinov, Leonid L.

2005-05-01

Astronomical observations of recent years have substantially extended our knowledge of the rotation of stars. Helioseismology has found out that the equator-to-pole decline in the angular velocity observed on the solar surface traces down to the deep interior of the Sun. New information has been gained regarding the dependence of the rotational nonuniformities on the angular velocity and mass of the star. These achievements have prompted the development of the theory of differential rotation, which is the focal point of this review. Nonuniform rotation results from the interaction of turbulent convection with rotation. The investigation into the turbulent mechanisms of angular-momentum transport has reached a level at which the obtained results can serve as the basis for developing quantitative models of stellar rotation. Such models contain virtually no free parameters but closely reproduce the helioseismological data on the internal rotation of the Sun. The theoretical predictions on the differential rotation of the stars agree with observations. A brief discussion is held here on the relation between the magnetic activity of stars and the nonuniformity of their rotation and on prospects for further development of the theory.

Weight-bearing computed tomography findings in varus ankle osteoarthritis: abnormal internal rotation of the talus in the axial plane.

PubMed

Kim, Ji-Beom; Yi, Young; Kim, Jae-Young; Cho, Jae-Ho; Kwon, Min-Soo; Choi, Seung-Hyuk; Lee, Woo-Chun

2017-08-01

To assess the incidence of abnormal internal rotation of the talus in the axial plane in patients with varus ankle osteoarthritis, and to determine whether this incidence differs from the severity of varus ankle osteoarthritis (moderate versus severe). We retrospectively evaluated weight-bearing computed tomography (CT) and plain radiographs of 52 ankles with no abnormalities (control group) and 96 ankles with varus osteoarthritis (varus-OA group), which were further stratified into a moderate-OA subgroup (50 ankles) and a severe-OA subgroup (46 ankles). A new radiographic parameter on weight-bearing CT, the talus rotation ratio, was used to assess the rotation of the talus in the axial plane. The normal range of the talus rotation ratio was defined as the 95% prediction interval for talus rotation ratio values in the control group. Abnormal internal rotation of the talus was defined for talus rotation ratio values above the normal range. We determined the incidence of abnormal internal rotation of the talus in the varus-OA group, moderate-OA subgroup, and severe-OA subgroup. In the varus-OA group, the incidence of abnormal internal rotation of the talus was 45% (43 ankles), which corresponded to an incidence of 32% (16 ankles) in the moderate-OA subgroup and 59% (27 ankles) in the severe-OA subgroup (p = 0.013). Our study demonstrates that abnormal internal rotation of the talus occurs in patients with varus ankle osteoarthritis, and is more frequently noted in severe than in moderate varus ankle osteoarthritis.

Immune suppression of human lymphoid tissues and cells in rotating suspension culture and onboard the International Space Station

PubMed Central

Fitzgerald, Wendy; Chen, Silvia; Walz, Carl; Zimmerberg, Joshua; Margolis, Leonid

2013-01-01

The immune responses of human lymphoid tissue explants or cells isolated from this tissue were studied quantitatively under normal gravity and microgravity. Microgravity was either modeled by solid body suspension in a rotating, oxygenated culture vessel or was actually achieved on the International Space Station (ISS). Our experiments demonstrate that tissues or cells challenged by recall antigen or by polyclonal activator in modeled microgravity lose all their ability to produce antibodies and cytokines and to increase their metabolic activity. In contrast, if the cells were challenged before being exposed to modeled microgravity suspension culture, they maintained their responses. Similarly, in microgravity in the ISS, lymphoid cells did not respond to antigenic or polyclonal challenge, whereas cells challenged prior to the space flight maintained their antibody and cytokine responses in space. Thus, immune activation of cells of lymphoid tissue is severely blunted both in modeled and true microgravity. This suggests that suspension culture via solid body rotation is sufficient to induce the changes in cellular physiology seen in true microgravity. This phenomenon may reflect immune dysfunction observed in astronauts during space flights. If so, the ex vivo system described above can be used to understand cellular and molecular mechanisms of this dysfunction. PMID:19609626

Anterolateral Knee Extra-articular Stabilizers: A Robotic Sectioning Study of the Anterolateral Ligament and Distal Iliotibial Band Kaplan Fibers.

PubMed

Geeslin, Andrew G; Chahla, Jorge; Moatshe, Gilbert; Muckenhirn, Kyle J; Kruckeberg, Bradley M; Brady, Alex W; Coggins, Ashley; Dornan, Grant J; Getgood, Alan M; Godin, Jonathan A; LaPrade, Robert F

2018-05-01

The individual kinematic roles of the anterolateral ligament (ALL) and the distal iliotibial band Kaplan fibers in the setting of anterior cruciate ligament (ACL) deficiency require further clarification. This will improve understanding of their potential contribution to residual anterolateral rotational laxity after ACL reconstruction and may influence selection of an anterolateral extra-articular reconstruction technique, which is currently a matter of debate. Hypothesis/Purpose: To compare the role of the ALL and the Kaplan fibers in stabilizing the knee against tibial internal rotation, anterior tibial translation, and the pivot shift in ACL-deficient knees. We hypothesized that the Kaplan fibers would provide greater tibial internal rotation restraint than the ALL in ACL-deficient knees and that both structures would provide restraint against internal rotation during a simulated pivot-shift test. Controlled laboratory study. Ten paired fresh-frozen cadaveric knees (n = 20) were used to investigate the effect of sectioning the ALL and the Kaplan fibers in ACL-deficient knees with a 6 degrees of freedom robotic testing system. After ACL sectioning, sectioning was randomly performed for the ALL and the Kaplan fibers. An established robotic testing protocol was utilized to assess knee kinematics when the specimens were subjected to a 5-N·m internal rotation torque (0°-90° at 15° increments), a simulated pivot shift with 10-N·m valgus and 5-N·m internal rotation torque (15° and 30°), and an 88-N anterior tibial load (30° and 90°). Sectioning of the ACL led to significantly increased tibial internal rotation (from 0° to 90°) and anterior tibial translation (30° and 90°) as compared with the intact state. Significantly increased internal rotation occurred with further sectioning of the ALL (15°-90°) and Kaplan fibers (15°, 60°-90°). At higher flexion angles (60°-90°), sectioning the Kaplan fibers led to significantly greater internal rotation when compared with ALL sectioning. On simulated pivot-shift testing, ALL sectioning led to significantly increased internal rotation and anterior translation at 15° and 30°; sectioning of the Kaplan fibers led to significantly increased tibial internal rotation at 15° and 30° and anterior translation at 15°. No significant difference was found when anterior tibial translation was compared between the ACL/ALL- and ACL/Kaplan fiber-deficient states on simulated pivot-shift testing or isolated anterior tibial load. The ALL and Kaplan fibers restrain internal rotation in the ACL-deficient knee. Sectioning the Kaplan fibers led to greater tibial internal rotation at higher flexion angles (60°-90°) as compared with ALL sectioning. Additionally, the ALL and Kaplan fibers contribute to restraint of the pivot shift and anterior tibial translation in the ACL-deficient knee. This study reports that the ALL and distal iliotibial band Kaplan fibers restrain anterior tibial translation, internal rotation, and pivot shift in the ACL-deficient knee. Furthermore, sectioning the Kaplan fibers led to significantly greater tibial internal rotation when compared with ALL sectioning at high flexion angles. These results demonstrate increased rotational knee laxity with combined ACL and anterolateral extra-articular knee injuries and may allow surgeons to optimize the care of patients with this injury pattern.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Triana, S. A.; Moravveji, E.; Pápics, P. I.

The internal angular momentum distribution of a star is the key to determining its evolution. Fortunately, stellar internal rotation can be probed through studies of rotationally split nonradial oscillation modes. In particular, the detection of nonradial gravity modes (g modes) in massive young stars has recently become feasible thanks to the Kepler space mission. Our goal is to derive the internal rotation profile of the Kepler B8V star KIC 10526294 through asteroseismology. We interpret the observed rotational splittings of its dipole g modes using four different approaches based on the best seismic models of the star and their rotational kernels.more » We show that these kernels can resolve differential rotation within the radiative envelope if a smooth rotational profile is assumed and if the observational errors are small. Based on Kepler data, we find that the rotation rate near the core-envelope boundary is well constrained to 163 ± 89 nHz. The seismic data are consistent with rigid rotation but a profile with counter-rotation within the envelope has a statistical advantage over constant rotation. Our study should be repeated for other massive stars with a variety of stellar parameters in order to determine the physical conditions that control the internal rotation profile of young massive stars, with the aim of improving the input physics of their models.« less

ANODAL TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) INCREASES ISOMETRIC STRENGTH OF SHOULDER ROTATORS MUSCLES IN HANDBALL PLAYERS.

PubMed

Hazime, Fuad Ahmad; da Cunha, Ronaldo Alves; Soliaman, Renato Rozenblit; Romancini, Ana Clara Bezerra; Pochini, Alberto de Castro; Ejnisman, Benno; Baptista, Abrahão Fontes

2017-06-01

Weakness of the rotator cuff muscles can lead to imbalances in the strength of shoulder external and internal rotators, change the biomechanics of the glenohumeral joint and predispose an athlete to injury. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has demonstrated promising results in a variety of health conditions. However few studies addressed its potential approach in the realm of athletics. The purpose of this study was to investigate if transcranial direct current stimulation (tDCS) technique increases the isometric muscle strength of shoulder external and internal rotators in handball athletes. Randomized, double-blind, placebo-controlled, crossover study. Eight female handball players aged between 17 and 21 years (Mean=19.65; SD=2.55) with 7.1 ± 4.8 years of experience in training, participating in regional and national competitions were recruited. Maximal voluntary isometric contraction (MVIC) of shoulder external and internal rotator muscles was evaluated during and after 30 and 60 minutes post one session of anodal and sham current (2mA; 0.057mA/cm 2 ) with a one-week interval between stimulations. Compared to baseline, MVIC of shoulder external and internal rotators significantly increased after real but not sham tDCS. Between-group differences were observed for external and internal rotator muscles. Maximal voluntary isometric contraction of external rotation increased significantly during tDCS, and 30 and 60 minutes post-tDCS for real tDCS compared to that for sham tDCS. For internal rotation MVIC increased significantly during and 60 minutes post-tDCS. The results indicate that transcranial direct current stimulation temporarily increases maximal isometric contractions of the internal and external rotators of the shoulder in handball players. 2.

Imagery May Arise from Associations Formed through Sensory Experience: A Network of Spiking Neurons Controlling a Robot Learns Visual Sequences in Order to Perform a Mental Rotation Task

PubMed Central

McKinstry, Jeffrey L.; Fleischer, Jason G.; Chen, Yanqing; Gall, W. Einar; Edelman, Gerald M.

2016-01-01

Mental imagery occurs “when a representation of the type created during the initial phases of perception is present but the stimulus is not actually being perceived.” How does the capability to perform mental imagery arise? Extending the idea that imagery arises from learned associations, we propose that mental rotation, a specific form of imagery, could arise through the mechanism of sequence learning–that is, by learning to regenerate the sequence of mental images perceived while passively observing a rotating object. To demonstrate the feasibility of this proposal, we constructed a simulated nervous system and embedded it within a behaving humanoid robot. By observing a rotating object, the system learns the sequence of neural activity patterns generated by the visual system in response to the object. After learning, it can internally regenerate a similar sequence of neural activations upon briefly viewing the static object. This system learns to perform a mental rotation task in which the subject must determine whether two objects are identical despite differences in orientation. As with human subjects, the time taken to respond is proportional to the angular difference between the two stimuli. Moreover, as reported in humans, the system fills in intermediate angles during the task, and this putative mental rotation activates the same pathways that are activated when the system views physical rotation. This work supports the proposal that mental rotation arises through sequence learning and the idea that mental imagery aids perception through learned associations, and suggests testable predictions for biological experiments. PMID:27653977

Global health training and international clinical rotations during residency: current status, needs, and opportunities.

PubMed

Drain, Paul K; Holmes, King K; Skeff, Kelley M; Hall, Thomas L; Gardner, Pierce

2009-03-01

Increasing international travel and migration have contributed to globalization of diseases. Physicians today must understand the global burden and epidemiology of diseases, the disparities and inequities in global health systems, and the importance of cross-cultural sensitivity. To meet these needs, resident physicians across all specialties have expressed growing interest in global health training and international clinical rotations. More residents are acquiring international experience, despite inadequate guidance and support from most accreditation organizations and residency programs. Surveys of global health training, including international clinical rotations, highlight the benefits of global health training as well as the need for a more coordinated approach. In particular, international rotations broaden a resident's medical knowledge, reinforce physical examination skills, and encourage practicing medicine among underserved and multicultural populations. As residents recognize these personal and professional benefits, a strong majority of them seek to gain international clinical experience. In conclusion, with feasible and appropriate administrative steps, all residents can receive global health training and be afforded the accreditation and programmatic support to participate in safe international rotations. The next steps should address accreditation for international rotations and allowance for training away from continuity clinics by residency accreditation bodies, and stipend and travel support for six or more weeks of call-free elective time from residency programs.

MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VIII. Faraday Rotation in Parsec-scale AGN Jets

NASA Astrophysics Data System (ADS)

Hovatta, Talvikki; Lister, Matthew L.; Aller, Margo F.; Aller, Hugh D.; Homan, Daniel C.; Kovalev, Yuri Y.; Pushkarev, Alexander B.; Savolainen, Tuomas

2012-10-01

We report observations of Faraday rotation measures for a sample of 191 extragalactic radio jets observed within the MOJAVE program. Multifrequency Very Long Baseline Array observations were carried out over 12 epochs in 2006 at four frequencies between 8 and 15 GHz. We detect parsec-scale Faraday rotation measures in 149 sources and find the quasars to have larger rotation measures on average than BL Lac objects. The median core rotation measures are significantly higher than in the jet components. This is especially true for quasars where we detect a significant negative correlation between the magnitude of the rotation measure and the de-projected distance from the core. We perform detailed simulations of the observational errors of total intensity, polarization, and Faraday rotation, and concentrate on the errors of transverse Faraday rotation measure gradients in unresolved jets. Our simulations show that the finite image restoring beam size has a significant effect on the observed rotation measure gradients, and spurious gradients can occur due to noise in the data if the jet is less than two beams wide in polarization. We detect significant transverse rotation measure gradients in four sources (0923+392, 1226+023, 2230+114, and 2251+158). In 1226+023 the rotation measure is for the first time seen to change sign from positive to negative over the transverse cuts, which supports the presence of a helical magnetic field in the jet. In this source we also detect variations in the jet rotation measure over a timescale of three months, which are difficult to explain with external Faraday screens and suggest internal Faraday rotation. By comparing fractional polarization changes in jet components between the four frequency bands to depolarization models, we find that an external purely random Faraday screen viewed through only a few lines of sight can explain most of our polarization observations, but in some sources, such as 1226+023 and 2251+158, internal Faraday rotation is needed.

Reproducibility of an optical measurement system for the clinical evaluation of active knee rotation in weight-bearing, healthy subjects.

PubMed

Testa, R; Chouteau, J; Viste, A; Cheze, L; Fessy, M-H; Moyen, B

2012-04-01

A knee is typically evaluated passively by a clinician during an office visit, without using dedicated measurement tools. When the knee is evaluated with the patient standing and actively participating in the movement, the results will differ than when the knee is passively moved through its range-of-motion by the surgeon. If a precise measurement system was available, it could provide additional information to the clinician during this evaluation. The goal of this study was to verify the reproducibility of a fast, flexible optical measurement system to measure rotational knee laxity during weight-bearing. Two passive reflective targets were placed on the legs of 11 subjects to monitor femur and tibia displacements in three dimensions. Subjects performed internal and external rotation movements with the knee extended or flexed 30°. During each movement, seven variables were measured: internal rotation, external rotation and overall laxity in extension and 30° flexion, along with neutral rotation value in 30° flexion. Measurement accuracy was also assessed and the right and left knees were compared. Reproducibility was assessed over two measurements sessions. The calculated intra-class correlation coefficient (ICC) for reproducibility was above 0.9 for five of the seven variables measured. The calculated ICC for the right/left comparison was above 0.75 for five of the seven variables measured. These results confirmed that the proposed system provides reproducible measurements. Our right/left comparison results were consistent with the published literature. This system is fast, reproducible and flexible, which makes it suitable for assessing various weight-bearing movements during clinical evaluations. Level III, experimental study. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

The benefits of international rotations to resource-limited settings for U.S. surgery residents.

PubMed

Henry, Jaymie A; Groen, Reinou S; Price, Raymond R; Nwomeh, Benedict C; Kingham, T Peter; Hardy, Mark A; Kushner, Adam L

2013-04-01

U.S. surgery residents increasingly are interested in international experiences. Recently, the Residency Review Committee approved international surgery rotations for credit toward graduation. Despite this growing interest, few U.S. surgery residency programs offer formal international rotations. We aimed to present the benefits of international surgery rotations and how these rotations contribute to the attainment of the 6 Accreditation Council for Graduate Medical Education (ACGME) competencies. An e-mail-based survey was sent in November 2011 to the 188 members of Surgeons OverSeas, a group of surgeons, residents, fellows, and medical students with experience working in resource-limited settings. They were asked to list 5 benefits of international rotations for surgery residents. The frequency of benefits was qualitatively grouped into 4 major categories: educational, personal, benefits to the foreign institution/Global Surgery, and benefits to the home institution. The themes were correlated with the 6 ACGME competencies. The 58 respondents (31% response rate) provided a total of 295 responses. Fifty themes were identified. Top benefits included learning to optimally function with limited resources, exposure to a wide variety of operative pathology, exposure to a foreign culture, and forming relationships with local counterparts. All ACGME competencies were covered by the themes. International surgery rotations to locations in which resources are constrained, operative diseases vary, and patient diversity abound provide unique opportunities for surgery residents to attain the 6 ACGME competencies. General surgery residency programs should be encouraged to establish formal international rotations as part of surgery training to promote resident education and assist with necessary oversight. Copyright © 2013 Mosby, Inc. All rights reserved.

Quantifying acromiohumeral distance in overhead athletes with glenohumeral internal rotation loss and the influence of a stretching program.

PubMed

Maenhout, Annelies; Van Eessel, Valerie; Van Dyck, Lieselot; Vanraes, Aagje; Cools, Ann

2012-09-01

Loss of internal rotation range of motion (ROM) on the dominant side is well documented in athletes performing overhead sports activity. This altered motion pattern has been shown to change glenohumeral and scapular kinematics. This could compromise the subacromial space and explain the association between glenohumeral internal rotation deficit (GIRD) and subacromial impingement. First, to quantify acromiohumeral distance (AHD) and compare between the dominant and nondominant side in overhead athletes with GIRD of more than 15°. Second, to investigate the effect of a sleeper stretch program on ROM and AHD. Controlled laboratory study. Range of motion was measured with a digital inclinometer and AHD was measured with ultrasound in 62 overhead athletes with GIRD (>15°) at baseline. Differences between sides were analyzed. Athletes were randomly allocated to the stretch (n = 30) or control group (n = 32). The stretch group performed a 6-week sleeper stretch program on the dominant side. Change of range of motion and AHD were measured and analyzed in both groups after 6 weeks. The dominant side showed a significant internal rotation deficit (-24.7° ± 6.3°) and horizontal adduction deficit (-11.8° ± 7.4°) and the dominant side AHD was significantly smaller with the arm at neutral (-0.4 ± 0.6 mm) and at 45° (-0.5 ± 0.8 mm) and 60° (-0.6 ± 0.7 mm) of active abduction compared with the nondominant side. After stretching, significant increase of internal rotation (+13.5° ± 0.8°), horizontal adduction (+10.6° ± 0.9°) ROM and AHD (+0.5 to +0.6mm) was observed at the dominant side of the stretch group compared with prestretching measurements. No significant change of AHD was seen in the nondominant side of the stretch group and in both sides of the control group. The AHD, a 2-dimensional measure for subacromial space, was found to be smaller on the dominant side in athletes with GIRD and was found to increase after a 6-week sleeper stretch program. These findings might provide insight into the relation between GIRD and subacromial impingement but future studies are needed to determine clinical implications.

Isokinetic strength differences between patients with primary reverse and total shoulder prostheses: muscle strength quantified with a dynamometer.

PubMed

Alta, Tjarco D W; Veeger, DirkJan H E J; de Toledo, Joelly M; Janssen, Thomas W J; Willems, W Jaap

2014-11-01

Range of motion after total shoulder arthroplasty is better than after reverse shoulder arthroplasty, however with similar clinical outcome. It is unclear if this difference can only be found in the different range of motion or also in the force generating capacity. (1) are isokinetically produced joint torques of reverse shoulder arthroplasty comparable to those of total shoulder arthroplasty? (2) Does this force-generating capacity correlate with functional outcome? Eighteen reverse shoulder arthroplasty patients (71years (SD 9years)) (21 shoulders, follow-up of 21months (SD 10months)) were recruited, 12 total shoulder arthroplasty patients (69years (SD 9years)) (14 shoulders, follow-up of 35months (SD 11months)). Pre- and post-operative Constant-Murley scores were obtained; two isokinetic protocols (ab-/adduction and ex-/internal rotations) at 60°/s were performed. Twelve of 18 reverse shoulder arthroplasty patients generated enough speed to perform the test (13 shoulders). Mean ab-/adduction torques are 16.3Nm (SD 5.6Nm) and 20.4Nm (SD 11.8Nm). All total shoulder arthroplasty patients generated enough speed (14 shoulders). Mean ab-/adduction torques are 32.1Nm (SD 13.3Nm) and 43.1Nm (SD 21.5Nm). Only 8 reverse shoulder arthroplasty patients (9 shoulders) could perform ex-/internal rotation tasks and all total shoulder arthroplasty patients. Mean ex-/internal rotation torques are 9.3Nm (SD 4.7Nm) and 9.2Nm (SD 2.1Nm) for reverse shoulder arthroplasty, and 17.9Nm (SD 7.7Nm) and 23.5Nm (SD 10.6Nm) for total shoulder arthroplasty. Significant correlations between sub-scores: activity, mobility and strength and external rotation torques for reverse shoulder arthroplasty. Moderate to strong correlation for sub-scores: strength in relation to abduction, adduction and internal rotation torques for total shoulder arthroplasty. Shoulders with a total shoulder arthroplasty are stronger. This can be explained by the absence of rotator cuff muscles and (probably) medialized center of rotation in reverse shoulder arthroplasty. The strong correlation between external rotation torques and post-operative Constant-Murley sub-scores demonstrates that external rotation is essential for good clinical functioning in reverse shoulder arthroplasty. Copyright © 2014 Elsevier Ltd. All rights reserved.

A comparison of trapezius muscle activities of different shoulder abduction angles and rotation conditions during prone horizontal abduction

PubMed Central

Lim, Jin Yong; Lee, Jung Seok; Mun, Byeong Mu; Kim, Tae Ho

2015-01-01

[Purpose] This study examined the differences in the activities of three parts of the trapezius muscle—the upper trapezius (UT), middle trapezius (MT), and lower trapezius (LT)—among three different rotation conditions of the shoulders, while subjects performed prone horizontal abduction (PHA) at 30°, 60°, 90°, and 120° of abduction. [Subjects and Methods] The subjects of this experimental study were 16 healthy male adults. Surface electromyography was used to collect data on the activity of each part of the trapezius. A two-way analysis of variance was used to compare the activities of each area of the trapezius—the UT, MT, and LT—among internal rotation (IR), the neutral position (NP), and external rotation (ER) of the shoulders during PHA with shoulder abduction of 30°, 60°, 90°, and 120°. [Results] Activity of the UT, MT, and LT significantly increased as the shoulder abduction angle increased during PHA. There was a significant difference only in the activity of the LT, with change in shoulder rotation. In addition, the muscle activity of the LT was highest during shoulder IR at 120°. [Conclusion] Although activity of the LT was the highest during IR at 120 abduction, PHA accompanied by ER at an abduction angle of 120° would be effective at eliciting high activity in the LT when PHA is performed. Nonetheless, at an early stage of rehabilitation, PHA accompanied by ER at low abduction angles of 30° and 60° would be desirable to elicit low activity of the UT and high activity of the LT. PMID:25642047

Early experience in establishing and evaluating an ACGME-approved international general surgery rotation.

PubMed

Tarpley, Margaret; Hansen, Erik; Tarpley, John L

2013-01-01

In 2011, the Accreditation Council for Graduate Medical Education Surgery Residency Review Committee first provided guidelines for elective international general surgery rotations. The Vanderbilt general surgery residency program received Surgery Residency Review Committee approval for a fourth-year elective in Kenya beginning in the 2011-2012 academic year. Because this rotation would break ground culturally and geographically, and as an educational partnership, a briefing and debriefing process was developed for this ground-breaking year. Our objectives were to prepare residents to maximize the experience without competing for cases with local trainees or overburdening the host institution and to perform continuous quality assessment and improvement as each resident returned back. Briefing included health protection strategies, a procedures manual containing step-by-step preparation activities, and cultural-sensitivity training. Institutional Review Board exemption approval was obtained to administer a questionnaire created for returning residents concerning educational value, relations with local trainees, physical environment, and personal perceptions that would provide the scaffold for the debriefing conference. The questionnaire coupled with the debriefing discussion for the first 9 participants revealed overall satisfaction with the rotation and the briefing process, good health, and no duty hours or days-off issues. Other findings include the following: (1) emotional effect of observing African families weigh cost in medical decision making; (2) satisfactory access to educational resources; (3) significant exposure to specialties such as urology and radiology; and (4) toleration of 4 weeks as a single and expressed need for leisure activity materials such as books, DVDs, or games. The responses triggered adjustments in the briefing sessions and travel preparation. The host institution invited the residents to return for the 2012-2013 year as well as 2013-2014. Detailed preparation and the follow-up evaluation for assessment and improvement of this nascent international surgery experience are associated with resident satisfaction and the host institution has agreed to continue the rotation. Copyright © 2013 Association of Program Directors in Surgery. All rights reserved.

Roles of Shape and Internal Structure in Rotational Disruption of Asteroids

NASA Astrophysics Data System (ADS)

Hirabayashi, Masatoshi; Scheeres, Daniel Jay

2015-08-01

An active research area over the last decade has been to explore configuration changes of rubble pile asteroids due to rotationally induced disruption, initially driven by the remarkable fact that there is a spin period threshold of 2 hr for asteroids larger than a few hundred meters in size. Several different disruption modes due to rapid rotation can be identified, as surface shedding, fission and failure of the internal structure. Relevant to these discussions are many observations of asteroid shapes that have revealed a diversity of forms such as oblate spheroids with equatorial ridges, strongly elongated shapes and contact binaries, to say nothing of multi-body systems. With consideration that rotationally induced deformation is one of the primary drivers of asteroid evolution, we have been developing two techniques for investigating the structure of asteroids, while accounting for their internal mechanical properties through plastic theory. The first technique developed is an analytical model based on limit analysis, which provides rigorous bounds on the asteroid mechanical properties for their shapes to remain stable. The second technique applies finite element model analysis that accounts for plastic deformation. Combining these models, we have explored the correlation between unique shape features and failure modes. First, we have been able to show that contact binary asteroids preferentially fail at their narrow necks at a relatively slow spin period, due to stress concentration. Second, applying these techniques to the breakup event of active asteroid P/2013 R3, we have been able to develop explicit constraints on the cohesion within rubble pile asteroids. Third, by probing the effect of inhomogeneous material properties, we have been able to develop conditions for whether an oblate body will fail internally or through surface shedding. These different failure modes can be tested by measuring the density distribution within a rubble pile body through determination of its gravity field. This talk will explore these different modes of failure and motivate divergent theories of failure that depend on properties of rubble piles.

Helioseismic Constraints on the Gradient of Angular Velocity at the Base of the Solar Convection Zone

NASA Technical Reports Server (NTRS)

Kosovichev, A. G.

1996-01-01

The layer of transition from the nearly rigid rotation of the radiative interior to the latitudinal differential rotation of the convection zone plays a significant role in the internal dynamics of the Sun. Using rotational splitting coefficients of the p-mode frequencies, obtained during 1986-1990 at the Big Bear Solar Observatory, we have found that the thickness of the transitional layer is 0.09 +/- 0.04 solar radii (63 +/- 28 Mm), and that most of the transition occurs beneath the adiabatically stratified part of the convection zone, as suggested by the dynamo theories of the 22 yr solar activity cycle.

Does the Powers™ strap influence the lower limb biomechanics during running?

PubMed

Greuel, Henrike; Herrington, Lee; Liu, Anmin; Jones, Richard K

2017-09-01

Previous research has reported a prevalence of running related injuries in 25.9% to 72% of all runners. A greater hip internal rotation and adduction during the stance phase in running has been associated with many running related injuries, such as patellofemoral pain. Researchers in the USA designed a treatment device 'the Powers™ strap' to facilitate an external rotation of the femur and to thereby control abnormal hip and knee motion during leisure and sport activities. However, to date no literature exists to demonstrate whether the Powers™ strap is able to reduce hip internal rotation during running. 22 healthy participants, 11 males and 11 females (age: 27.45±4.43 years, height: 1.73±0.06m, mass: 66.77±9.24kg) were asked to run on a 22m track under two conditions: without and with the Powers™ strap. Three-dimensional motion analysis was conducted using ten Qualisys OQUS 7 cameras (Qualisys AB, Sweden) and force data was captured with three AMTI force plates (BP600900, Advanced Mechanical Technology, Inc.USA). Paired sample t-tests were performed at the 95% confidence interval on all lower limb kinematic and kinetic data. The Powers™ strap significantly reduced hip and knee internal rotation throughout the stance phase of running. These results showed that the Powers™ strap has the potential to influence hip motion during running related activities, in doing so this might be beneficial for patients with lower limb injuries. Future research should investigate the influence of the Powers™ strap in subjects who suffer from running related injuries, such as patellofemoral pain. Copyright © 2017 Elsevier B.V. All rights reserved.

The Microwave Spectrum of Partially Deuterated Species of Dimethyl Ether

NASA Astrophysics Data System (ADS)

Lauvergnat, D.; Margulès, L.; Motiyenko, R. A.; Guillemin, J.-C.; Coudert, L. H.

2011-06-01

Dimethyl ether is a molecule of astrophysical interest spectroscopically well characterized. It is one of the simplest molecules with two methyl groups undergoing large amplitude internal rotations. Due to deuterium enrichment in the interstellar medium, one can reasonably expect that partially deuterated species of dimethyl ether might be detected. However, there are no spectroscopic results about the microwave spectrum of such species. A theoretical calculation of the rotation-torsion energy levels of the partially deuterated species of dimethyl ether has been undertaken aided by ab initio calculations. The approach accounts for the complicated torsion-rotation interactions displayed by this molecule and for the fact that deuteration leads to changes of the bidimensional internal rotation effective potential energy surface. Due to zero-point energy contributions from the 19 small amplitude vibrational modes, this surface no longer displays G36 symmetry. Rotation-torsion energy levels are computed treating the two angles of internal rotation as active coordinates and evaluating Hamiltonian matrix elements with the help of Gaussian quadrature. It is hoped that the present results will allow us to understand the microwave spectrum of the mono deuterated species CH_2DOCH_3 which has been recorded in Lille with the new sub millimeter wave spectrometer (150--950 GHz) based on harmonic generation of solid-state sources. [2] Snyder, Buhl, and Schwartz, Astrophys. J. Letters 191 (1974) L79. [3] Endres, Drouin, Pearson, Müller, Lewen, Schlemmer, and Giesen, A&A 504 (2009) 635. [4] Solomon and Woolf, Astrophys. J. Letters 180 (1973) L89. [5] Lauvergnat and Nauts, J. Chem. Phys. 116 (2002) 8560; and Light and Bačić, J. Chem. Phys. 87 (1987) 4008.

Isometric hip-rotator torque production at varying degrees of hip flexion.

PubMed

Johnson, Sam; Hoffman, Mark

2010-02-01

Hip torque production is associated with certain knee injuries. The hip rotators change function depending on hip angle. To compare hip-rotator torque production between 3 angles of hip flexion, limbs, and sexes. Descriptive. University sports medicine research laboratory. 15 men and 15 women, 19-39 y. Three 6-s maximal isometric contractions of the hip external and internal rotators at 10 degrees, 40 degrees, and 90 degrees of hip flexion on both legs. Average torque normalized to body mass. Internal-rotation torque was greatest at 90 degrees of hip flexion, followed by 40 degrees of hip flexion and finally 10 degrees of hip flexion. External-rotation torque was not different based on hip flexion. The nondominant leg's external rotators were stronger than the dominant leg's, but the reverse was true for internal rotators. Finally, the men had more overall rotator torque. Hip-rotation torque production varies between flexion angle, leg, and sex. Clinicians treating lower extremity problems need to be aware of these differences.

Glenohumeral internal rotation deficit in throwing athletes: current perspectives

PubMed Central

Rose, Michael B; Noonan, Thomas

2018-01-01

Glenohumeral internal rotation deficit (GIRD) is an adaptive process in which the throwing shoulder experiences a loss of internal rotation (IR). GIRD has most commonly been defined by a loss of >20° of IR compared to the contralateral shoulder. Total rotational motion of the shoulder is the sum of internal and external rotation and may be more important than the absolute value of IR loss. Pathologic GIRD has been defined as a loss of IR combined with a loss of total rotational motion. The leading pathologic process in GIRD is posterior capsular and rotator-cuff tightness, due to the repetitive cocking that occurs with the overhead throwing motion. GIRD has been associated with numerous pathologic conditions, including posterior superior labral tears, partial articular-sided rotator-cuff tears, and superior labral anterior-to-posterior tears. The mainstay of treatment for patients with GIRD is posterior capsular stretching and strengthening to improve scapular mechanics. In patients who fail nonoperative therapy, shoulder arthroscopy can be performed. Arthroscopic surgery in the high-level throwing athlete should be to restore them to their functional baseline with the minimum amount of intervention possible. PMID:29593438

Torsion-rotation intensities in methanol

NASA Astrophysics Data System (ADS)

Pearson, John

Methanol exists in numerous kinds of astronomical objects featuring a wide range of local conditions. The light nature of the molecule coupled with the internal rotation of the methyl group with respect to the hydroxyl group results in a rich, strong spectrum that spans the entire far-infrared region. As a result, any modest size observational window will have a number of strong methanol transitions. This has made it the gas of choice for testing THz receivers and to extract the local physical conditions from observations covering small frequency windows. The latter has caused methanol to be dubbed the Swiss army knife of astrophysics. Methanol has been increasingly used in this capacity and will be used even more for subsequent investigations into the Herschel archive, and with SOFIA and ALMA. Interpreting physical conditions on the basis of a few methanol lines requires that the molecular data, line positions, intensities, and collision rates, be complete, consistent and accurate to a much higher level than previously required for astrophysics. The need for highly reliable data is even more critical for modeling the two classes of widespread maser action and many examples of optical pumping through the torsional bands. Observation of the torsional bands in the infrared will be a unique opportunity to directly connect JWST observations with those of Herschel, SOFIA, and ALMA. The theory for the intensities of torsion-rotation transitions in a molecule featuring a single internally rotating methyl group is well developed after 70 years of research. However, other than a recent very preliminary and not completely satisfactory investigation of a few CH3OH torsional bands, this theory has never been experimentally tested for any C3V internal rotor. More alarming is a set of recent intensity calibrated microwave measurements that showed deviations relative to calculations of up to 50% in some ground state rotational transitions commonly used by astronomers to extract local conditions. We propose a comprehensive study of the intensities of methanol involving both the pure rotation bands and the torsional bands to serve as a benchmark for the theory used to calculate the infrared activity of all single methyl internal rotation molecules.

Effect of limb rotation on radiographic alignment in total knee arthroplasties.

PubMed

Radtke, Kerstin; Becher, Christoph; Noll, Yvonne; Ostermeier, Sven

2010-04-01

Even in a well-aligned total knee arthroplasty (TKA), limb rotation at the time of radiographic assessment will alter the measurement of alignment. This could influence the radiographic outcome of TKA. The purpose of this study was to evaluate the effect of limb rotation on radiographic alignment after TKA and to establish a re-calculation of this rotation by using existing radiographic landmarks. Synthetic femur and tibia (Sawbones), Inc. Vashon Island, WA) were used to create a TKA of the Triathlon knee prosthesis system (Stryker), Limerick, Ireland). The femoral alignment was 6.5 degrees valgus. The model was fixed in an upright stand. Five series of nine anteroposterior (AP) long leg radiographs were taken on a 30 cm x 120 cm plates in full extension with the limb rotated, in 5 degrees increments, from 20 degrees external rotation to 20 degrees internal rotation. After digitizing each radiograph (Scanner Hewlett Packard XJ 527), an observer measured the anatomic mechanical angle of the femur [AMA ( degrees )], the mechanical lateral proximal femur angle [mLPFA ( degrees )], the mechanical lateral distal femur angle [mLDFA ( degrees )], the mechanical medial proximal tibia angle [mMPTA ( degrees )] and the mechanical lateral distal tibia angle [mLDTA ( degrees )] using a digital measurement software (MediCAD, Hectec, Altfraunhofen, Germany). Besides, the observer measured the geometrical distances of the femoral component figured on the long leg radiograph. A ratio of one distance to another was measured (called femoral component distance ratio). The average radiographic anatomic alignment ranged from 6.827 degrees AMA (SD = 0.22 degrees ) in 20 degrees internal rotation to 4.627 degrees AMA (SD = 0.22 degrees ) in 20 degrees external rotation. Average mLPFA ( degrees ) ranged from 101.63 degrees (SD = 0.63) in 20 degrees internal rotation to 93.60 degrees (SD = 0.74 degrees ) in 20 degrees external rotation. Average mLDFA ( degrees ) ranged from 90.59 degrees (SD = 3.01 degrees ) in 20 degrees internal rotation to 86.76 degrees (SD = 0.36 degrees ) in 20 degrees external rotation. Average mMPTA ( degrees ) ranged from 90.35 degrees (SD = 0.81 degrees ) in 20 degrees internal rotation to 88.49 degrees (SD = 0.52 degrees ) in 20 degrees external rotation. Average mLDTA ( degrees ) ranged from 98.89 degrees (SD = 2.3 degrees ) in 20 degrees internal rotation to 90.53 degrees (SD = 3.39 degrees ) in 20 degrees external rotation. Without an application of limb rotation, the femoral component distance ratio was measured to be 0.89 (SD = 0.01), in 20 degrees internal rotation 0.63 (SD = 0.01) and in 20 degrees external rotation 1.16 (SD = 0.01). Limb rotation had a highly statistically significant effect on measured anatomic alignment and mechanical angles. A correlation between limb rotation, anatomic mechanical angle, mechanical angles measured at femur and tibia and the femoral component distance ratio was established. As the anatomic mechanical angle and the femoral component distance ratio change linearly in the range of 20 degrees internal and external limb rotation, a calculation of the femoral component distance ratio could be used to re-calculate the limb rotation at the time of radiographic assessment to evaluate the evidence of a long leg radiograph.

Three-dimensional knee joint kinematics during golf swing and stationary cycling after total knee arthroplasty.

PubMed

Hamai, Satoshi; Miura, Hiromasa; Higaki, Hidehiko; Shimoto, Takeshi; Matsuda, Shuichi; Okazaki, Ken; Iwamoto, Yukihide

2008-12-01

The expectation of returning to sports activities after total knee arthroplasty (TKA) has become more important to patients than ever. To our knowledge, no studies have been published evaluating the three-dimensional knee joint kinematics during sports activity after TKA. Continuous X-ray images of the golf swing and stationary cycling were taken using a large flat panel detector for four and eight post-arthroplasty knees, respectively. The implant flexion and axial rotation angles were determined using a radiographic-based, image-matching technique. Both the golf swing from the set-up position to the top of the backswing, and the stationary cycling from the top position of the crank to the bottom position of the crank, produced progressive axial rotational motions (p = 0.73). However, the golf swing from the top of the backswing to the end of the follow-through produced significantly larger magnitudes of rotational motions in comparison to stationary cycling (p < 0.01). Excessive internal-external rotations generated from the top of the backswing to the end of the follow-through could contribute to accelerated polyethylene wear. However, gradual rotational movements were consistently demonstrated during the stationary cycling. Therefore, stationary cycling is recommended rather than playing golf for patients following a TKA who wish to remain physically active.

Comparison of shoulder internal rotation test with the elbow flexion test in the diagnosis of cubital tunnel syndrome.

PubMed

Ochi, Kensuke; Horiuchi, Yukio; Tanabe, Aya; Morita, Kozo; Takeda, Kentaro; Ninomiya, Ken

2011-05-01

To compare the shoulder internal rotation test-a new, provocative test-with the elbow flexion test in the diagnosis of cubital tunnel syndrome (CubTS). Twenty-five patients with CubTS were examined before and after surgery with 10 seconds each of the elbow flexion and shoulder internal rotation tests. Fifty-four asymptomatic individuals and 14 neuropathy patients with a diagnosis other than CubTS were also examined as control cases. For the shoulder internal rotation test, the patient's upper extremity was kept at 90° abduction, maximum internal rotation, and 10° flexion at the shoulder, with 90° elbow flexion and neutral position of the forearm and wrist, with finger extension. Test results were considered positive if any slight symptom attributable to CubTS occurred within 10 seconds. Extraneural pressure inside the cubital tunnel was intraoperatively measured with the positions of both the elbow flexion and shoulder internal rotation tests, in 15 of the CubTS cases. Statistical analyses were performed using Student's t-test with a confidence level of 95%. The preoperative sensitivity in CubTS cases was 80% in the 10-second shoulder internal rotation test and 36% in the 10-second elbow flexion test, and these differences were significant. None of the control cases had positive results in either test. All the CubTS cases improved with surgery; after surgery, neither test provoked symptoms in any surgical patient. The extraneural pressure increased in both provocative positions with no significant difference. Positive results for the 10-second shoulder internal rotation test were more sensitive than that for the elbow flexion test of the same duration and seemed specific to CubTS. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Extreme fluctuations of active Brownian motion

NASA Astrophysics Data System (ADS)

Pietzonka, Patrick; Kleinbeck, Kevin; Seifert, Udo

2016-05-01

In active Brownian motion, an internal propulsion mechanism interacts with translational and rotational thermal noise and other internal fluctuations to produce directed motion. We derive the distribution of its extreme fluctuations and identify its universal properties using large deviation theory. The limits of slow and fast internal dynamics give rise to a kink-like and parabolic behavior of the corresponding rate functions, respectively. For dipolar Janus particles in two- and three-dimensions interacting with a field, we predict a novel symmetry akin to, but different from, the one related to entropy production. Measurements of these extreme fluctuations could thus be used to infer properties of the underlying, often hidden, network of states.

Microwave Spectra and AB Initio Studies of the Ne-Acetone Complex

NASA Astrophysics Data System (ADS)

Gao, Jiao; Thomas, Javix; Xu, Yunjie; Jäger, Wolfgang

2015-06-01

Microwave spectra of the neon-acetone van der Waals complex were measured using a cavity-based molecular beam Fourier-transform microwave spectrometer in the region from 5 to 18 GHz. Both 20Ne and 22Ne containing isotopologues were studied and both c- and weaker a-type rotational transitions were observed. The transitions are split into multiplets due to the internal rotation of two methyl groups in acetone. Electronic structure calculations were done at the MP2 level of theory with the 6-311++g (2d, p) basis set for all atoms and the internal rotation barrier height of the methyl groups was determined to be about 2.8 kJ/mol. The ab initio rotational constants were the basis for our spectroscopic searches, but the multiplet structures and floppiness of the complex made the quantum number assignment very difficult. The assignment was finally achieved with the aid of constructing closed frequency loops and predicting internal rotation splittings using the XIAM code. Analyses of the spectra yielded rotational and centrifugal distortion constants, as well as internal rotation parameters, which were interpreted in terms of structure and internal dynamics of the complex. H. Hartwig and H. Dreizler, Z. Naturforsch. A 51, 923 (1996).

Low Barrier Methyl Rotation in 3-PENTYN-1-OL as Observed by Microwave Spectroscopy

NASA Astrophysics Data System (ADS)

Eibl, Konrad; Kannengießer, Raphaela; Stahl, Wolfgang; Nguyen, Ha Vinh Lam; Kleiner, Isabelle

2016-06-01

It is known that the barrier to internal rotation of the methyl groups in ethane (1) is about 1000 wn. If a C-C-triple bond is inserted between the methyl groups as a spacer (2), the torsional barrier is assumed to be dramatically lower, which is a common feature of ethinyl groups in general. To study this effect of almost free internal rotation, we measured the rotational spectrum of 3-pentyn-1-ol (3) by pulsed jet Fourier transform microwave spectroscopy in the frequency range from 2 to 26.5 GHz. Quantum chemical calculations at the MP2/6-311++G(d,p) level of theory yielded five stable conformers on the potential energy surface. The most stable conformer, which possesses C1 symmetry, was assigned and fitted using two theoretical approaches treating internal rotations, the rho axis method (BELGI-C1) and the combined axis method (XIAM). The molecular parameters as well as the internal rotation parameters were determined. A very low barrier to internal rotation of the methyl group of only 9.4545(95) wn was observed. R. M. Pitzer, Acc. Chem. Res., 1983, 16, 207-210

The effect of glenosphere diameter in reverse shoulder arthroplasty on muscle force, joint load, and range of motion.

PubMed

Langohr, G Daniel G; Giles, Joshua W; Athwal, George S; Johnson, James A

2015-06-01

Little is known about the effects of glenosphere diameter on shoulder joint loads. The purpose of this biomechanical study was to investigate the effects of glenosphere diameter on joint load, load angle, and total deltoid force required for active abduction and range of motion in internal/external rotation and abduction. A custom, instrumented reverse shoulder arthroplasty implant system capable of measuring joint load and varying glenosphere diameter (38 and 42 mm) and glenoid offset (neutral and lateral) was implanted in 6 cadaveric shoulders to provide at least 80% power for all variables. A shoulder motion simulator was used to produce active glenohumeral and scapulothoracic motion. All implant configurations were tested with active and passive motion with joint kinematics, loads, and moments recorded. At neutral and lateralized glenosphere positions, increasing diameter significantly increased joint load (+12 ± 21 N and +6 ± 9 N; P < .01) and deltoid load required for active abduction (+9 ± 22 N and +11 ± 15 N; P < .02), whereas joint load angle was unaffected (P > .8). Passive internal rotation was reduced with increased diameter at both neutral and lateralized glenosphere positions (-6° ± 6° and -12° ± 6°; P < .002); however, external rotation was not affected (P > .05). At neutral glenosphere position, increasing diameter increased the maximum angles of both adduction (+1° ± 1°; P = .03) and abduction (+8° ± 9°; P < .05). Lateralization also increased abduction range of motion compared with neutral (P < .01). Although increasing glenosphere diameter significantly increased joint load and deltoid force, the clinical impact of these changes is presently unclear. Internal rotation, however, was reduced, which contradicts previous bone modeling studies, which we postulate is due to increased posterior capsular tension as it is forced to wrap around a larger 42 mm implant assembly. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Adolescents' Self-Efficacy to Overcome Barriers to Physical Activity Scale

ERIC Educational Resources Information Center

Dwyer, John J. M.; Chulak, Tala; Maitland, Scott; Allison, Kenneth R.; Lysy, Daria C.; Faulkner, Guy E. J.; Sheeshka, Judy

2012-01-01

This paper describes a revised measure of self-efficacy to overcome barriers to moderate and vigorous physical activity in a sample of 484 high school students in Toronto, Ontario. The students had a mean age of 15.3 years. Principal axis factoring with oblique rotation yielded five factors: self-efficacy to overcome internal, harassment, physical…

Assessment of the midflexion rotational laxity in posterior-stabilized total knee arthroplasty.

PubMed

Hino, Kazunori; Kutsuna, Tatsuhiko; Oonishi, Yoshio; Watamori, Kunihiko; Kiyomatsu, Hiroshi; Iseki, Yasutake; Watanabe, Seiji; Ishimaru, Yasumitsu; Miura, Hiromasa

2017-11-01

To evaluate changes in midflexion rotational laxity before and after posterior-stabilized (PS)-total knee arthroplasty (TKA). Twenty-nine knees that underwent PS-TKA were evaluated. Manual mild passive rotational stress was applied to the knees, and the internal-external rotational angle was measured automatically by a navigation system at 30°, 45°, 60°, and 90° of knee flexion. The post-operative internal rotational laxity was statistically significantly increased compared to the preoperative level at 30°, 45°, 60°, and 90° of flexion. The post-operative external rotational laxity was statistically significantly decreased compared to the preoperative level at 45° and 60° of flexion. The post-operative internal-external rotational laxity was statistically significantly increased compared to the preoperative level only at 30° of flexion. The preoperative and post-operative rotational laxity showed a significant correlation at 30°, 45°, 60°, and 90° of flexion. Internal-external rotational laxity increases at the initial flexion range due to resection of both the anterior or posterior cruciate ligaments and retention of the collateral ligaments in PS-TKA. Preoperative and post-operative rotational laxity indicated a significant correlation at the midflexion range. This study showed that a large preoperative rotational laxity increased the risk of a large post-operative laxity, especially at the initial flexion range in PS-TKA. III.

Job rotation and internal marketing for increased job satisfaction and organisational commitment in hospital nursing staff.

PubMed

Chen, Su-Yueh; Wu, Wen-Chuan; Chang, Ching-Sheng; Lin, Chia-Tzu

2015-04-01

To develop or enhance the job satisfaction and organisational commitment of nurses by implementing job rotation and internal marketing practices. No studies in the nursing management literature have addressed the integrated relationships among job rotation, internal marketing, job satisfaction and organisational commitment. This cross-sectional study included 266 registered nurses (response rate 81.8%) in two southern Taiwan hospitals. Software used for data analysis were SPSS 14.0 and AMOS 14.0 (structural equation modelling). Job rotation and internal marketing positively affect the job satisfaction and organisational commitment of nurses, and their job satisfaction positively affects their organisational commitment. Job rotation and internal marketing are effective strategies for improving nursing workforce utilisation in health-care organisations because they help to achieve the ultimate goals of increasing the job satisfaction of nurses and encouraging them to continue working in the field. This in turn limits the vicious cycle of high turnover and low morale in organisations, which wastes valuable human resources. Job rotation and internal marketing help nursing personnel acquire knowledge, skills and insights while simultaneously improving their job satisfaction and organisational commitment. © 2013 John Wiley & Sons Ltd.

Clinical and neuropathological study about the neurotization of the suprascapular nerve in obstetric brachial plexus lesions

PubMed Central

2009-01-01

Background The lack of recovery of active external rotation of the shoulder is an important problem in children suffering from brachial plexus lesions involving the suprascapular nerve. The accessory nerve neurotization to the suprascapular nerve is a standard procedure, performed to improve shoulder motion in patients with brachial plexus palsy. Methods We operated on 65 patients with obstetric brachial plexus palsy (OBPP), aged 5-35 months (average: 19 months). We assessed the recovery of passive and active external rotation with the arm in abduction and in adduction. We also looked at the influence of the restoration of the muscular balance between the internal and the external rotators on the development of a gleno-humeral joint dysplasia. Intraoperatively, suprascapular nerve samples were taken from 13 patients and were analyzed histologically. Results Most patients (71.5%) showed good recovery of the active external rotation in abduction (60°-90°). Better results were obtained for the external rotation with the arm in abduction compared to adduction, and for patients having only undergone the neurotization procedure compared to patients having had complete plexus reconstruction. The neurotization operation has a positive influence on the glenohumeral joint: 7 patients with clinical signs of dysplasia before the reconstructive operation did not show any sign of dysplasia in the postoperative follow-up. Conclusion The neurotization procedure helps to recover the active external rotation in the shoulder joint and has a good prevention influence on the dysplasia in our sample. The nerve quality measured using histopathology also seems to have a positive impact on the clinical results. PMID:19744351

Knee Joint Kinematics and Kinetics During a Lateral False-Step Maneuver

PubMed Central

Golden, Grace M.; Pavol, Michael J.; Hoffman, Mark A.

2009-01-01

Abstract Context: Cutting maneuvers have been implicated as a mechanism of noncontact anterior cruciate ligament (ACL) injuries in collegiate female basketball players. Objective: To investigate knee kinematics and kinetics during running when the width of a single step, relative to the path of travel, was manipulated, a lateral false-step maneuver. Design: Crossover design. Setting: University biomechanics laboratory. Patients or Other Participants: Thirteen female collegiate basketball athletes (age  =  19.7 ± 1.1 years, height  =  172.3 ± 8.3 cm, mass  =  71.8 ± 8.7 kg). Intervention(s): Three conditions: normal straight-ahead running, lateral false step of width 20% of body height, and lateral false step of width 35% of body height. Main Outcome Measure(s): Peak angles and internal moments for knee flexion, extension, abduction, adduction, internal rotation, and external rotation. Results: Differences were noted among conditions in peak knee angles (flexion [P < .01], extension [P  =  .02], abduction [P < .01], and internal rotation [P < .01]) and peak internal knee moments (abduction [P < .01], adduction [P < .01], and internal rotation [P  =  .03]). The lateral false step of width 35% of body height was associated with larger peak flexion, abduction, and internal rotation angles and larger peak abduction, adduction, and internal rotation moments than normal running. Peak flexion and internal rotation angles were also larger for the lateral false step of width 20% of body height than for normal running, whereas peak extension angle was smaller. Peak internal rotation angle increased progressively with increasing step width. Conclusions: Performing a lateral false-step maneuver resulted in changes in knee kinematics and kinetics compared with normal running. The differences observed for lateral false steps were consistent with proposed mechanisms of ACL loading, suggesting that lateral false steps represent a hitherto neglected mechanism of noncontact ACL injury. PMID:19771289

Reorientational Dynamics of Enzymes Adsorbed on Quartz: A Temperature-Dependent Time-Resolved TIRF Anisotropy Study

PubMed Central

Czeslik, C.; Royer, C.; Hazlett, T.; Mantulin, W.

2003-01-01

The preservation of enzyme activity and protein binding capacity upon protein adsorption at solid interfaces is important for biotechnological and medical applications. Because these properties are partly related to the protein flexibility and mobility, we have studied the internal dynamics and the whole-body reorientational rates of two enzymes, staphylococcal nuclease (SNase) and hen egg white lysozyme, over the temperature range of 20–80°C when the proteins are adsorbed at the silica/water interface and, for comparison, when they are dissolved in buffer. The data were obtained using a combination of two experimental techniques, total internal reflection fluorescence spectroscopy and time-resolved fluorescence anisotropy measurements in the frequency domain, with the protein Trp residues as intrinsic fluorescence probes. It has been found that the internal dynamics and the whole-body rotation of SNase and lysozyme are markedly reduced upon adsorption over large temperature ranges. At elevated temperatures, both protein molecules appear completely immobilized and the fractional amplitudes for the whole-body rotation, which are related to the order parameter for the local rotational freedom of the Trp residues, remain constant and do not approach zero. This behavior indicates that the angular range of the Trp reorientation within the adsorbed proteins is largely restricted even at high temperatures, in contrast to that of the dissolved proteins. The results of this study thus provide a deeper understanding of protein activity at solid surfaces. PMID:12668461

GLENOHUMERAL MOTION DEFICITS: FRIEND OR FOE?

PubMed Central

Wilk, Kevin E.; Davies, George; Ellenbecker, Todd; Reinold, Mike

2013-01-01

In most shoulder conditions a loss of glenohumeral motion results in shoulder performance impairments. However, in the overhead athlete loss of glenohumeral internal rotation, termed glenohumeral internal rotation deficiency (GIRD), is a normal phenomenon that should be expected. Without a loss of glenohumeral internal rotation the overhead athlete will not have the requisite glenohumeral external rotation needed to throw a baseball at nearly 100 miles per hour, or serve a tennis ball at velocities of 120 miles per hour or more. Not all GIRD is pathologic. The authors of this manuscript have defined two types of GIRD; one that is normal and one that is pathologic. Anatomical GIRD (aGIRD) is one that is normal in overhead athletes and is characterized by a loss of internal rotation of less than 18°‐20° with symmetrical total rotational motion (TROM) bilaterally. Pathologic GIRD (pGIRD) is when there is a loss of glenohumeral internal rotation greater than 18°‐20° with a corresponding loss of TROM greater than 5° when compared bilaterally. A more problematic motion restriction may be that of a loss of TROM in the glenohumeral joint. Recent evidence supports that a loss of TROM is predictive of future injury to the shoulder in professional athletes. Additionally, external rotation deficiency (ERD), the difference between external rotation (ER) of the throwing shoulder and the non‐throwing shoulder of less than 5°, may be another predictor of future shoulder injury and disability. Level of Evidence: 5 PMID:24175137

A unified internal model theory to resolve the paradox of active versus passive self-motion sensation

PubMed Central

Angelaki, Dora E

2017-01-01

Brainstem and cerebellar neurons implement an internal model to accurately estimate self-motion during externally generated (‘passive’) movements. However, these neurons show reduced responses during self-generated (‘active’) movements, indicating that predicted sensory consequences of motor commands cancel sensory signals. Remarkably, the computational processes underlying sensory prediction during active motion and their relationship to internal model computations during passive movements remain unknown. We construct a Kalman filter that incorporates motor commands into a previously established model of optimal passive self-motion estimation. The simulated sensory error and feedback signals match experimentally measured neuronal responses during active and passive head and trunk rotations and translations. We conclude that a single sensory internal model can combine motor commands with vestibular and proprioceptive signals optimally. Thus, although neurons carrying sensory prediction error or feedback signals show attenuated modulation, the sensory cues and internal model are both engaged and critically important for accurate self-motion estimation during active head movements. PMID:29043978

Influence of Medial Collateral Ligament Release for Internal Rotation of Tibia in Posterior-Stabilized Total Knee Arthroplasty: A Cadaveric Study.

PubMed

Wada, Keizo; Hamada, Daisuke; Tamaki, Shunsuke; Higashino, Kosaku; Fukui, Yoshihiro; Sairyo, Koichi

2017-01-01

Previous studies suggested that changes in kinematics in total knee arthroplasty (TKA) affected satisfaction level. The aim of this cadaveric study was to evaluate the effect of medial collateral ligament (MCL) release by multiple needle puncture on knee rotational kinematics in posterior-stabilized TKA. Six fresh, frozen cadaveric knees were included in this study. All TKA procedures were performed with an image-free navigation system using a 10-mm polyethylene insert. Tibial internal rotation was assessed to evaluate intraoperative knee kinematics. Multiple needle puncturing was performed 5, 10, and 15 times for the hard portion of the MCL at 90° knee flexion. Kinematic analysis was performed after every 5 punctures. After performing 15 punctures, a 14-mm polyethylene insert was inserted, and kinematic analysis was performed. The tibial internal rotation angle at maximum knee flexion without multiple needle puncturing was significantly larger (9.42°) than that after 15 punctures (3°). Negative correlation (Pearson r = -0.715, P < .001) between tibial internal rotation angle at maximum knee flexion and frequency of puncture was observed. The tibial internal rotation angle with a 14-mm insert was significantly larger (7.25°) compared with the angle after 15 punctures. Tibial internal rotation during knee flexion was reduced by extensive MCL release using multiple needle puncturing and was recovered by increasing of medial tightness. From the point of view of knee kinematics, medial tightness should be allowed to maintain the internal rotation angle of the tibia during knee flexion which might lead to patient satisfaction. Copyright © 2016 Elsevier Inc. All rights reserved.

The American Society of Shoulder and Elbow Therapists' consensus statement on rehabilitation following arthroscopic rotator cuff repair.

PubMed

Thigpen, Charles A; Shaffer, Michael A; Gaunt, Bryce W; Leggin, Brian G; Williams, Gerald R; Wilcox, Reg B

2016-04-01

This is a consensus statement on rehabilitation developed by the American Society of Shoulder and Elbow Therapists. The purpose of this statement is to aid clinical decision making during the rehabilitation of patients after arthroscopic rotator cuff repair. The overarching philosophy of rehabilitation is centered on the principle of the gradual application of controlled stresses to the healing rotator cuff repair with consideration of rotator cuff tear size, tissue quality, and patient variables. This statement describes a rehabilitation framework that includes a 2-week period of strict immobilization and a staged introduction of protected, passive range of motion during weeks 2-6 postoperatively, followed by restoration of active range of motion, and then progressive strengthening beginning at postoperative week 12. When appropriate, rehabilitation continues with a functional progression for return to athletic or demanding work activities. This document represents the first consensus rehabilitation statement developed by a multidisciplinary society of international rehabilitation professionals specifically for the postoperative care of patients after arthroscopic rotator cuff repair. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Outcomes of reverse shoulder arthroplasty using a mini 25-mm glenoid baseplate.

PubMed

Athwal, George S; Faber, Kenneth J

2016-01-01

As worldwide use of reverse shoulder arthroplasty (RSA) increases, a range of implant sizes may be required to match regional and ethnic variation in patients' height and bone size. The purpose of this study was to report the outcomes of RSA using a mini 25-mm-diameter glenoid baseplate in smaller patients with rotator cuff arthropathy. Between 2009 and 2012, 28 patients underwent RSA for cuff-tear arthropathy using a 25-mm circular glenoid baseplate (Aequlais Reversed, Tornier, Bloomington, MN, USA). Twenty-four patients were able to return for comprehensive follow-up. The mean height of the entire cohort was 158 ± 10 cm (5 ft. 2 in.). The indication to use a smaller baseplate was a combination of preoperative templating using computed tomography (CT) and intraoperative measurements of glenoid width. At a mean of 36 ± 8 months' follow-up, there were no revisions or glenoid-sided failures. The mean American Shoulder and Elbow Surgeons (ASES) score was 70 ± 10, the Simple Shoulder Test (SST) was 10 ± 2, the Constant was 60 ± 10 and the Disabilities of the Arm, Shoulder and Hand (DASH) was 18 ± 15. Mean active forward elevation was 140 ± 15°, active external rotation was 21 ± 15° and active internal rotation was to the sacroiliac joint. Mean shoulder strength in flexion was 5.2 ± 1.7 kg, in external rotation was 2.9 ± 1.4 kg and in internal rotation was 4.3 ± 1.2 kg. Radiographs demonstrated no evidence of glenoid loosening. There was, however, a 62 % rate of scapular notching. Short-term outcomes of mini 25-mm baseplate RSA in proportionally smaller patients are good and demonstrate implant safety and effectiveness. Scapular notching rates are worrisome, and additional follow-up is necessary to determine if notching is progressive and becomes symptomatic.

MOJAVE: MONITORING OF JETS IN ACTIVE GALACTIC NUCLEI WITH VLBA EXPERIMENTS. VIII. FARADAY ROTATION IN PARSEC-SCALE AGN JETS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hovatta, Talvikki; Lister, Matthew L.; Aller, Margo F.

2012-10-01

We report observations of Faraday rotation measures for a sample of 191 extragalactic radio jets observed within the MOJAVE program. Multifrequency Very Long Baseline Array observations were carried out over 12 epochs in 2006 at four frequencies between 8 and 15 GHz. We detect parsec-scale Faraday rotation measures in 149 sources and find the quasars to have larger rotation measures on average than BL Lac objects. The median core rotation measures are significantly higher than in the jet components. This is especially true for quasars where we detect a significant negative correlation between the magnitude of the rotation measure andmore » the de-projected distance from the core. We perform detailed simulations of the observational errors of total intensity, polarization, and Faraday rotation, and concentrate on the errors of transverse Faraday rotation measure gradients in unresolved jets. Our simulations show that the finite image restoring beam size has a significant effect on the observed rotation measure gradients, and spurious gradients can occur due to noise in the data if the jet is less than two beams wide in polarization. We detect significant transverse rotation measure gradients in four sources (0923+392, 1226+023, 2230+114, and 2251+158). In 1226+023 the rotation measure is for the first time seen to change sign from positive to negative over the transverse cuts, which supports the presence of a helical magnetic field in the jet. In this source we also detect variations in the jet rotation measure over a timescale of three months, which are difficult to explain with external Faraday screens and suggest internal Faraday rotation. By comparing fractional polarization changes in jet components between the four frequency bands to depolarization models, we find that an external purely random Faraday screen viewed through only a few lines of sight can explain most of our polarization observations, but in some sources, such as 1226+023 and 2251+158, internal Faraday rotation is needed.« less

Internal rotation in halogenated toluenes: Rotational spectrum of 2,3-difluorotoluene

NASA Astrophysics Data System (ADS)

Nair, K. P. Rajappan; Herbers, Sven; Grabow, Jens-Uwe; Lesarri, Alberto

2018-07-01

The microwave rotational spectrum of 2,3-difluorotoluene has been studied by pulsed supersonic jet using Fourier transform microwave spectroscopy. The tunneling splitting due to the methyl internal rotation in the ground torsional state could be unambiguously identified and the three-fold (V3) potential barrier hindering the internal rotation of the methyl top was determined as 2518.70(15) J/mol. The ground-state rotational parameters for the parent and seven 13C isotopic species in natural abundance were determined with high accuracy, including all quartic centrifugal distortion constants. The molecular structure was derived using the substitution (rs) method. From the rotational constants of the different isotopic species the rs structure as well as the r0 structure was determined. Supporting ab initio (MP2) and DFT (B3LYP) calculations provided comparative values for the potential barrier and molecular parameters.

Effect of forearm axially rotated posture on shoulder load and shoulder abduction / flexion angles in one-armed arrest of forward falls.

PubMed

Hsu, Hsiu-Hao; Chou, You-Li; Lou, Shu-Zon; Huang, Ming-Jer; Chou, Paul Pei-Hsi

2011-03-01

Falling onto the outstretched hand is the most common cause of upper extremity injury. This study develops an experimental model for evaluating the shoulder load during a simulated forward fall onto one hand with three different forearm axially rotated postures, and examines the shoulder abduction angle and shoulder flexion angle in each case. Fifteen healthy young male subjects with an average age of 23.7 years performed a series of one-armed arrests from a height of 5 cm onto a force plate. The kinematics and kinetics of the upper extremity were analyzed for three different forearm postures, namely 45° externally rotated, non-rotated, and 45° internally rotated. The shoulder joint load and shoulder abduction/flexion angles were significantly dependent on the rotational posture of the forearm. The shoulder medio-lateral shear forces in the externally rotated group were found to be 1.61 and 2.94 times higher than those in the non-rotated and internally rotated groups, respectively. The shoulder flexion angles in the externally rotated, non-rotated and internally rotated groups were 0.6°, 8.0° and 19.2°, respectively, while the corresponding shoulder abduction angles were 6.1°, 34.1° and 46.3°, respectively. In falls onto the outstretched hand, an externally rotated forearm posture should be avoided in order to reduce the medio-lateral shear force acting on the shoulder joint. In falls of this type, a 45° internally rotated forearm posture represents the most effective fall strategy in terms of minimizing the risk of upper extremity injuries. Copyright © 2010 Elsevier Ltd. All rights reserved.

Resistance training is accompanied by increases in hip strength and changes in lower extremity biomechanics during running.

PubMed

Snyder, Kelli R; Earl, Jennifer E; O'Connor, Kristian M; Ebersole, Kyle T

2009-01-01

Movement and muscle activity of the hip have been shown to affect movement of the lower extremity, and been related to injury. The purpose of this study was to determine if increased hip strength affects lower extremity mechanics during running. Within subject, repeated measures design. Fifteen healthy women volunteered. Hip abduction and external rotation strength were measured using a hand-held dynamometer. Three-dimensional biomechanical data of the lower extremity were collected during running using a high-speed motion capture system. Measurements were made before, at the mid-point, and after a 6-week strengthening program using closed-chain hip rotation exercises. Joint range of motion (rearfoot eversion, knee abduction, hip adduction, and internal rotation), eversion velocity, eversion angle at heel strike, and peak joint moments (rearfoot inversion, knee abduction, hip abduction, and external rotation) were analyzed using repeated measures analysis of variance (P

Observed differences in upper extremity forces, muscle efforts, postures, velocities and accelerations across computer activities in a field study of office workers.

PubMed

Bruno Garza, J L; Eijckelhof, B H W; Johnson, P W; Raina, S M; Rynell, P W; Huysmans, M A; van Dieën, J H; van der Beek, A J; Blatter, B M; Dennerlein, J T

2012-01-01

This study, a part of the PRedicting Occupational biomechanics in OFfice workers (PROOF) study, investigated whether there are differences in field-measured forces, muscle efforts, postures, velocities and accelerations across computer activities. These parameters were measured continuously for 120 office workers performing their own work for two hours each. There were differences in nearly all forces, muscle efforts, postures, velocities and accelerations across keyboard, mouse and idle activities. Keyboard activities showed a 50% increase in the median right trapezius muscle effort when compared to mouse activities. Median shoulder rotation changed from 25 degrees internal rotation during keyboard use to 15 degrees external rotation during mouse use. Only keyboard use was associated with median ulnar deviations greater than 5 degrees. Idle activities led to the greatest variability observed in all muscle efforts and postures measured. In future studies, measurements of computer activities could be used to provide information on the physical exposures experienced during computer use. Practitioner Summary: Computer users may develop musculoskeletal disorders due to their force, muscle effort, posture and wrist velocity and acceleration exposures during computer use. We report that many physical exposures are different across computer activities. This information may be used to estimate physical exposures based on patterns of computer activities over time.

Seismic constraints on rotation of Sun-like star and mass of exoplanet.

PubMed

Gizon, Laurent; Ballot, Jérome; Michel, Eric; Stahn, Thorsten; Vauclair, Gérard; Bruntt, Hans; Quirion, Pierre-Olivier; Benomar, Othman; Vauclair, Sylvie; Appourchaux, Thierry; Auvergne, Michel; Baglin, Annie; Barban, Caroline; Baudin, Fréderic; Bazot, Michaël; Campante, Tiago; Catala, Claude; Chaplin, William; Creevey, Orlagh; Deheuvels, Sébastien; Dolez, Noël; Elsworth, Yvonne; García, Rafael; Gaulme, Patrick; Mathis, Stéphane; Mathur, Savita; Mosser, Benoît; Régulo, Clara; Roxburgh, Ian; Salabert, David; Samadi, Réza; Sato, Kumiko; Verner, Graham; Hanasoge, Shravan; Sreenivasan, Katepalli R

2013-08-13

Rotation is thought to drive cyclic magnetic activity in the Sun and Sun-like stars. Stellar dynamos, however, are poorly understood owing to the scarcity of observations of rotation and magnetic fields in stars. Here, inferences are drawn on the internal rotation of a distant Sun-like star by studying its global modes of oscillation. We report asteroseismic constraints imposed on the rotation rate and the inclination of the spin axis of the Sun-like star HD 52265, a principal target observed by the CoRoT satellite that is known to host a planetary companion. These seismic inferences are remarkably consistent with an independent spectroscopic observation (rotational line broadening) and with the observed rotation period of star spots. Furthermore, asteroseismology constrains the mass of exoplanet HD 52265b. Under the standard assumption that the stellar spin axis and the axis of the planetary orbit coincide, the minimum spectroscopic mass of the planet can be converted into a true mass of 1.85(-0.42)(+0.52)M(Jupiter), which implies that it is a planet, not a brown dwarf.

Seismic constraints on rotation of Sun-like star and mass of exoplanet

PubMed Central

Gizon, Laurent; Ballot, Jérome; Michel, Eric; Stahn, Thorsten; Vauclair, Gérard; Bruntt, Hans; Quirion, Pierre-Olivier; Benomar, Othman; Vauclair, Sylvie; Appourchaux, Thierry; Auvergne, Michel; Baglin, Annie; Barban, Caroline; Baudin, Fréderic; Bazot, Michaël; Campante, Tiago; Catala, Claude; Chaplin, William; Creevey, Orlagh; Deheuvels, Sébastien; Dolez, Noël; Elsworth, Yvonne; García, Rafael; Gaulme, Patrick; Mathis, Stéphane; Mathur, Savita; Mosser, Benoît; Régulo, Clara; Roxburgh, Ian; Salabert, David; Samadi, Réza; Sato, Kumiko; Verner, Graham; Hanasoge, Shravan; Sreenivasan, Katepalli R.

2013-01-01

Rotation is thought to drive cyclic magnetic activity in the Sun and Sun-like stars. Stellar dynamos, however, are poorly understood owing to the scarcity of observations of rotation and magnetic fields in stars. Here, inferences are drawn on the internal rotation of a distant Sun-like star by studying its global modes of oscillation. We report asteroseismic constraints imposed on the rotation rate and the inclination of the spin axis of the Sun-like star HD 52265, a principal target observed by the CoRoT satellite that is known to host a planetary companion. These seismic inferences are remarkably consistent with an independent spectroscopic observation (rotational line broadening) and with the observed rotation period of star spots. Furthermore, asteroseismology constrains the mass of exoplanet HD 52265b. Under the standard assumption that the stellar spin axis and the axis of the planetary orbit coincide, the minimum spectroscopic mass of the planet can be converted into a true mass of , which implies that it is a planet, not a brown dwarf. PMID:23898183

Rotating full- and reduced-dimensional quantum chemical models of molecules

NASA Astrophysics Data System (ADS)

Fábri, Csaba; Mátyus, Edit; Császár, Attila G.

2011-02-01

A flexible protocol, applicable to semirigid as well as floppy polyatomic systems, is developed for the variational solution of the rotational-vibrational Schrödinger equation. The kinetic energy operator is expressed in terms of curvilinear coordinates, describing the internal motion, and rotational coordinates, characterizing the orientation of the frame fixed to the nonrigid body. Although the analytic form of the kinetic energy operator might be very complex, it does not need to be known a priori within this scheme as it is constructed automatically and numerically whenever needed. The internal coordinates can be chosen to best represent the system of interest and the body-fixed frame is not restricted to an embedding defined with respect to a single reference geometry. The features of the technique mentioned make it especially well suited to treat large-amplitude nuclear motions. Reduced-dimensional rovibrational models can be defined straightforwardly by introducing constraints on the generalized coordinates. In order to demonstrate the flexibility of the protocol and the associated computer code, the inversion-tunneling of the ammonia (14NH3) molecule is studied using one, two, three, four, and six active vibrational degrees of freedom, within both vibrational and rovibrational variational computations. For example, the one-dimensional inversion-tunneling model of ammonia is considered also for nonzero rotational angular momenta. It turns out to be difficult to significantly improve upon this simple model. Rotational-vibrational energy levels are presented for rotational angular momentum quantum numbers J = 0, 1, 2, 3, and 4.

Influence of Playing a Prolonged Tennis Match on Shoulder Internal Range of Motion.

PubMed

Martin, Caroline; Kulpa, Richard; Ezanno, Felix; Delamarche, Paul; Bideau, Benoit

2016-08-01

Shoulder range of motion (ROM) deficits have been identified as an injury risk factor among tennis players. It is well known that shoulder internal rotation deficit increases with age and years of play, but there is a lack of knowledge regarding the influence of a prolonged tennis match on shoulder ROM. To examine changes in shoulder ROM during a prolonged tennis match. Descriptive laboratory study. Shoulder passive internal and external rotation ROM were measured on 8 male tennis players before, every 30 minutes during, and just after a 3-hour tennis match. Total ROM was calculated as the combination of shoulder internal and external rotations. Ball velocity on the serve was measured with a radar gun before, at midmatch, and just after the match. Decreases in shoulder internal rotation (-20.8°; P = .005), total ROM (-24.6°; P = .001), and serve velocity (-1.8 m/s; P = .002) were observed at the end of the match. No statistically significant difference was observed for shoulder external rotation after the match (P = .460). Passive shoulder internal rotation and total ROM are significantly decreased during a 3-hour tennis match. The results show that a prolonged tennis match play can modify values of shoulder ROM. © 2016 The Author(s).

Effects of whole-body cryotherapy in the management of adhesive capsulitis of the shoulder.

PubMed

Ma, Sang-Yeol; Je, Hyun Dong; Jeong, Ji Hoon; Kim, Hae-Young; Kim, Hyeong-Dong

2013-01-01

To compare 2 different treatment approaches, physical therapy modalities, and joint mobilization versus whole-body cryotherapy (WBC) combined with physical therapy modalities and joint mobilization, for symptoms of adhesive capsulitis (AC) of the shoulder. A randomized trial. Hospital. Patients with AC of the shoulder (N=30). Patients were randomly assigned to 2 groups. The WBC group received physical therapy modalities, passive joint mobilization of the shoulder, and WBC, whereas the non-WBC group received only physical therapy modalities and passive joint mobilization of the shoulder. Visual analog scale (VAS), active range of motion (ROM) of flexion, abduction, internal and external rotation of the shoulder, and the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) were measured before and after the intervention. A statistically significant difference between groups was found for the VAS, active ROM of flexion, abduction, internal rotation, and external rotation, and the ASES with greater improvements in the WBC group (Ps<.01). Overall, both groups showed a significant improvement in all outcome measures and ROM measures from pre to post at a level of P<.01. There is significant improvement with the addition of WBC to treatment interventions in this sample of patients. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

In vivo axial humero-ulnar rotation in normal and dysplastic canine elbow joints.

PubMed

Rohwedder, Thomas; Fischer, Martin; Böttcher, Peter

2018-04-01

To prospectively compare relative axial (internal-external) humero-ulnar rotation in normal and dysplastic canine elbow joints. Six normal elbows (five dogs) and seven joints (six dogs) with coronoid disease were examined. After implantation of 0.8 mm tantalum beads into humerus and ulna, biplanar x-ray movies of the implanted elbows were taken while dogs were walking on a treadmill. Based on the 2D bead coordinates of the synchronized x-ray movies virtual 3D humero-ulnar animations were calculated. Based on these, relative internal-external humero-ulnar rotation was measured over the first third of stance phase and expressed as maximal rotational amplitude. Amplitudes from three consecutive steps were averaged and groupwise compared using an unpaired t-test. In normal elbow joints mean axial relative humero-ulnar rotation was 2.9° (SD 1.1). Dysplastic joints showed a significantly greater rotational amplitude (5.3°, SD 2.0; p = 0.0229, 95% confidence interval 0.4-4.4). Dysplastic elbow joints show greater relative internal-external humero-ulnar rotation compared to normal elbows, which might reflect rotational joint instability. Increased relative internal-external humero-ulnar rotation might alter physiological joint contact and pressure patterns. Future studies are needed to verify if this plays a role in the pathogenesis of medial coronoid disease. Schattauer GmbH.

A randomised trial into the effect of an isolated hip abductor strengthening programme and a functional motor control programme on knee kinematics and hip muscle strength.

PubMed

Palmer, Kathryn; Hebron, Clair; Williams, Jonathan M

2015-05-03

Dynamic knee valgus and internal femoral rotation are proposed to be contributory risk factors for patellofemoral pain and anterior cruciate ligament injuries. Multimodal interventions including hip abductor strengthening or functional motor control programmes have a positive impact of pain, however their effect on knee kinematics and muscle strength is less clear. The aim of this study was to examine the effect of isolated hip abductor strengthening and a functional motor control exercise on knee kinematics and hip abductor strength. This prospective, randomised, repeated measures design included 29 asymptomatic volunteers presenting with increase knee valgus and femoral internal rotation. Participants completed either isolated hip abductor strengthening or a functional motor control exercise for 5 weeks. Knee kinematics were measured using inertial sensors during 2 functional activities and hip abductor strength measured using a load cell during isometric hip abduction. There were no significant differences in dynamic knee valgus and internal rotation following the isolated hip abductor or functional motor control intervention, and no significant differences between the groups for knee angles. Despite this, the actual magnitude of reduction in valgus was 10° and 5° for the functional motor control group and strengthening group respectively. The actual magnitude of reduction in internal rotation was 9° and 18° for the functional motor control group and strengthening group respectively. Therefore there was a tendency towards clinically significant improvements in knee kinematics in both exercise groups. A statistically significant improvement in hip abductor strength was evident for the functional motor control group (27% increase; p = 0.008) and strengthening group (35% increase; p = 0.009) with no significant difference between the groups being identified (p = 0.475). Isolated hip strengthening and functional motor control exercises resulted in non-statistically significant changes in knee kinematics, however there was a clear trend towards clinically meaningful reductions in valgus and internal rotation. Both groups demonstrated similar significant gains in hip abductor strength suggesting either approach could be used to strengthen the hip abductors.

Hand-held dynamometer testing of the internal and external rotator musculature based on selected positions to establish normative data and unilateral ratios.

PubMed

Riemann, Bryan L; Davies, George J; Ludwig, Lauren; Gardenhour, Helen

2010-12-01

Objective documentation is needed of shoulder internal and external rotator strength using hand-held dynamometry in selected positions commonly used in a clinic. We compared strength measures and unilateral ratios between gender, limbs (dominant, nondominant), and 3 testing positions. We hypothesized that men would be stronger than women, the dominant shoulder would be stronger than the nondominant shoulder, and the seated neutral (0° adduction) and seated 30° abduction, 30° scaption, 30° diagonal (30°-30°-30°) positions would be stronger than the prone at 90°-90° position. Three positions (prone at 90°, seated at neutral, and seated at 30°-30°-30°) were evaluated in 181 individuals using hand-held dynamometry. Three separate 3-factor (limb by position by gender) analyses of variance were conducted on internal rotation, external rotation, and unilateral ratios. Although the dominant limb was significantly stronger (P < .001) than the nondominant for internal rotation, there was no difference for external rotation. The external rotators demonstrated significantly greater strength in the prone at 90° position compared with the seated at neutral (P = .001) and seated at 30°-30°-30° (P = .002) positions. The internal rotators demonstrated significantly greater (P = .036) strength in the neutral position than in the prone at 90° position for the women. The unilateral ratio of external rotators/internal rotators ranged from 86% to 99%. For the women, the prone at 90° ratio was significantly greater than seated at neutral (P = .001) and seated at 30°-30°-30° (P = .001) positions. Moderate strength relationships (r = 0.506 to 0.572) were revealed between body mass and all strength measures. The results of this study provide evidence to interpret normative data, bilateral comparisons and unilateral ratios of the internal/external rotators in the 3 selected positions. Because there are no differences between the seated at neutral and 30°-30°-30° positions and the advantages it offers, we recommend the 30°-30°-30° position for testing and the initiation of rehabilitation. Copyright © 2010 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Impact of abutment rotation and angulation on marginal fit: theoretical considerations.

PubMed

Semper, Wiebke; Kraft, Silvan; Mehrhof, Jurgen; Nelson, Katja

2010-01-01

Rotational freedom of various implant positional index designs has been previously calculated. To investigate its clinical relevance, a three-dimensional simulation was performed to demonstrate the influence of rotational displacements of the abutment on the marginal fit of prosthetic superstructures. Idealized abutments with different angulations (0, 5, 10, 15, and 20 degrees) were virtually constructed (SolidWorks Office Premium 2007). Then, rotational displacement was simulated with various degrees of rotational freedom (0.7, 0.95, 1.5, 1.65, and 1.85 degrees). The resulting horizontal displacement of the abutment from the original position was quantified in microns, followed by a simulated pressure-less positioning of superstructures with defined internal gaps (5 µm, 60 µm, and 100 µm). The resulting marginal gap between the abutment and the superstructure was measured vertically with the SolidWorks measurement tool. Rotation resulted in a displacement of the abutment of up to 157 µm at maximum rotation and angulation. Interference of a superstructure with a defined internal gap of 5 µm placed on the abutment resulted in marginal gaps up to 2.33 mm at maximum rotation and angulation; with a 60-µm internal gap, the marginal gaps reached a maximum of 802 µm. Simulation using a superstructure with an internal gap of 100 µm revealed a marginal gap of 162 µm at abutment angulation of 20 degrees and rotation of 1.85 degrees. The marginal gaps increased with the degree of abutment angulation and the extent of rotational freedom. Rotational displacement of the abutment influenced prosthesis misfit. The marginal gaps between the abutment and the superstructure increased with the rotational freedom of the index and the angulation of the abutment.

Rotating Interns' Images of Practitioners of Five Medical Specialties.

ERIC Educational Resources Information Center

Sangal, Rahul

1979-01-01

A study of rotating interns' images of medical practitioners focuses on what images the interns have of obstetrician-gynecologists, pediatricians, internists, psychiatrists, and surgeons, and seeks to determine whether these images differ according to choice of specialty for postgraduate work. (JMD)

Microwave Spectroscopy and Proton Transfer Dynamics in the Formic Acid-Acetic Acid Dimer

NASA Astrophysics Data System (ADS)

Howard, B. J.; Steer, E.; Page, F.; Tayler, M.; Ouyang, B.; Leung, H. O.; Marshall, M. D.; Muenter, J. S.

2012-06-01

The rotational spectrum of the doubly hydrogen-bonded {hetero} dimer formed between formic acid and acetic acid has been recorded between 4 and 18 GHz using a pulsed-nozzle Fourier transform microwave spectrometer. Each rigid-molecule rotational transition is split into four as a result of two concurrent tunnelling motions, one being proton transfer between the two acid molecules, and the other the torsion/rotation of the methyl group within the acetic acid. We present a full assignment of the spectrum for {J} = 1 to {J} = 7 for these four torsion/tunnelling states. Spectra have been observed for the main isotopic species, with deuterium substitution at the C of the formic acid and all 13C species in natural abundance, The observed transitions are fitted to within a few kilohertz using a molecule-fixed effective rotational Hamiltonian for the separate {A} and {E} vibrational species of the G12 permutation-inversion group which is applicable to this complex. To reduce the effects of internal angular momentum, a non-principal axis system is used throughout. Interpretation of the internal motion uses an internal-vibration and overall rotation scheme, and full sets of rotational and centrifugal distortion constants are determined. The proton tunnelling rates and the internal angular momentum of the methyl group in the {E} states is interpreted in terms of a dynamical model which involves coupled proton transfer and internal rotation. The resulting potential energy surface not only describes these internal motions, but can also explain the observed shifts in rotational constants between {A} and {E} species, and the deviations of the tunnelling frequencies from the expected 2:1 ratio. It also permits the determination of spectral constants free from the contamination effects of the internal dynamics. M.C.D. Tayler, B. Ouyang and B.J. Howard, J. Chem. Phys., {134}, 054316 (2011).

Reliability of Measurement of Glenohumeral Internal Rotation, External Rotation, and Total Arc of Motion in 3 Test Positions

PubMed Central

Kevern, Mark A.; Beecher, Michael; Rao, Smita

2014-01-01

Context: Athletes who participate in throwing and racket sports consistently demonstrate adaptive changes in glenohumeral-joint internal and external rotation in the dominant arm. Measurements of these motions have demonstrated excellent intrarater and poor interrater reliability. Objective: To determine intrarater reliability, interrater reliability, and standard error of measurement for shoulder internal rotation, external rotation, and total arc of motion using an inclinometer in 3 testing procedures in National Collegiate Athletic Association Division I baseball and softball athletes. Design: Cross-sectional study. Setting: Athletic department. Patients or Other Participants Thirty-eight players participated in the study. Shoulder internal rotation, external rotation, and total arc of motion were measured by 2 investigators in 3 test positions. The standard supine position was compared with a side-lying test position, as well as a supine test position without examiner overpressure. Results: Excellent intrarater reliability was noted for all 3 test positions and ranges of motion, with intraclass correlation coefficient values ranging from 0.93 to 0.99. Results for interrater reliability were less favorable. Reliability for internal rotation was highest in the side-lying position (0.68) and reliability for external rotation and total arc was highest in the supine-without-overpressure position (0.774 and 0.713, respectively). The supine-with-overpressure position yielded the lowest interrater reliability results in all positions. The side-lying position had the most consistent results, with very little variation among intraclass correlation coefficient values for the various test positions. Conclusions: The results of our study clearly indicate that the side-lying test procedure is of equal or greater value than the traditional supine-with-overpressure method. PMID:25188316

Correlation of glenohumeral internal rotation deficit and total rotational motion to shoulder injuries in professional baseball pitchers.

PubMed

Wilk, Kevin E; Macrina, Leonard C; Fleisig, Glenn S; Porterfield, Ronald; Simpson, Charles D; Harker, Paul; Paparesta, Nick; Andrews, James R

2011-02-01

Glenohumeral internal rotation deficit (GIRD) indicates a 20° or greater loss of internal rotation of the throwing shoulder compared with the nondominant shoulder. To determine whether GIRD and a deficit in total rotational motion (external rotation + internal rotation) compared with the nonthrowing shoulder correlate with shoulder injuries in professional baseball pitchers. Case series; Level of evidence, 4. Over 3 competitive seasons (2005 to 2007), passive range of motion measurements were evaluated on the dominant and nondominant shoulders for 170 pitcher-seasons. This included 122 professional pitchers during the 3 seasons of data collection, in which some pitchers were measured during multiple seasons. Ranges of motion were measured with a bubble goniometer during the preseason, by the same examiner each year. External and internal rotation of the glenohumeral joint was assessed with the participant supine and the arm abducted 90° in the plane of the scapula, with the scapula stabilized anteriorly at the coracoid process. The reproducibility of the test methods had an intraclass correlation coefficient of .81. Days in which the player was unable to participate because of injury or surgery were recorded during the season by the medical staff of the team and defined as an injury. Pitchers with GIRD (n = 40) were nearly twice as likely to be injured as those without but without statistical significance (P = .17). Pitchers with total rotational motion deficit greater than 5° had a higher rate of injury. Minor league pitchers were more likely than major league pitchers to be injured. However, when players were injured, major league pitchers missed a significantly greater number of games than minor league pitchers. Compared with pitchers without GIRD, pitchers with GIRD appear to be at a higher risk for injury and shoulder surgery.

Patellofemoral pain and asymmetrical hip rotation.

PubMed

Cibulka, Michael T; Threlkeld-Watkins, Julie

2005-11-01

Patellofemoral joint problems are the most common overuse injury of the lower extremity, and altered femoral or hip rotation may play a role in patellofemoral pain. The purpose of this case report is to describe the evaluation of and intervention for a patient with asymmetrical hip rotation and patellofemoral pain. The patient was a 15-year-old girl with an 8-month history of anterior right knee pain, without known trauma or injury. Prior to intervention, her score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 24%. Right hip medial (internal) rotation was less than left hip medial rotation, and manual muscle testing showed weakness of the right hip internal rotator and abductor muscles. The intervention was aimed at increasing right hip medial rotation, improving right hip muscle strength (eg, the muscle force exerted by a muscle or a group of muscles to overcome a resistance), and eliminating anterior right knee pain. After 6 visits (14 days), passive left and right hip medial rotations were symmetrical, and her right hip internal rotator and abductor muscle grades were Good plus. Her WOMAC score was 0%. The patient had right patellofemoral pain and an uncommon pattern of asymmetrical hip rotation, with diminished hip medial rotation and excessive hip lateral (external) rotation on the right side. The patient's outcomes suggest that femoral or hip joint asymmetry may be related to patellofemoral joint pain.

Relation Between Subacromial Bursitis on Ultrasonography and Efficacy of Subacromial Corticosteroid Injection in Rotator Cuff Disease: A Prospective Comparison Study.

PubMed

Lee, Doo-Hyung; Hong, Ji Yeon; Lee, Michael Young; Kwack, Kyu-Sung; Yoon, Seung-Hyun

2017-05-01

To evaluate the correlations between subacromial bursitis (bursal thickening and effusion) on ultrasonography and its response to subacromial corticosteroid injection in patients with rotator cuff disease. Prospective, longitudinal comparison study. University-affiliated tertiary care hospital. Patients with rotator cuff disease (N=69) were classified into 3 groups based on ultrasonographic findings; (1) normative bursa group (group 1, n=23): bursa and effusion thickness <1mm; (2) bursa thickening group (group 2, n=22): bursa thickness >2mm and effusion thickness <1mm; and (3) bursa effusion group (group 3, n=24): bursa thickness <1mm and effusion thickness >2mm. A single subacromial injection with 20mg of triamcinolone acetonide. Visual analog scale (VAS) of shoulder pain, Shoulder Disability Questionnaire (SDQ), angles of active shoulder range of motion (flexion, abduction, external rotation, and internal rotation), and bursa and effusion thickness at pre- and posttreatment at week 8. There were no significant differences between the 3 groups in demographic characteristics pretreatment. Groups 2 and 3 showed a significant difference compared with group 1 in changes on the VAS and abduction; group 3 showed a significant difference compared with group 1 in changes of the SDQ, internal rotation, and external rotation; and all groups showed significant differences when compared with each other (groups 1 and 3, 2 and 3, and 1 and 2) in changes of thickness. A patient with ultrasonographic observation of subacromial bursitis, instead of normative bursa, can expect better outcome with subacromial corticosteroid injection. Therefore, we recommend a careful selection of patients using ultrasonography prior to injection. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Video- Demonstrations of Stable and Unstable Solid Body Rotation on the International Space Station

NASA Technical Reports Server (NTRS)

2003-01-01

Saturday Morning Science, the science of opportunity series of applied experiments and demonstrations, performed aboard the International Space Station (ISS) by Expedition 6 astronaut Dr. Don Pettit, revealed some remarkable findings. In this video clip, Pettit demonstrates stable and unstable modes for solid body rotation on the ISS. Using a hard cover textbook, he demonstrates that it will rotate stably about the longest and shortest axis, which represent the maximum and minimum movements of Inertia. Trying to rotate the book around an intermediate axis results in an unstable rotation in which the book appears to flip-flop while it rotates.

The Effect of Shoulder Plyometric Training on Amortization Time and Upper-Extremity Kinematics.

PubMed

Swanik, Kathleen A; Thomas, Stephen J; Struminger, Aaron H; Bliven, Kellie C Huxel; Kelly, John D; Swanik, Charles B

2016-12-01

Plyometric training is credited with providing benefits in performance and dynamic restraint. However, limited prospective data exist quantifying kinematic adaptations such as amortization time, glenohumeral rotation, and scapulothoracic position, which may underlie the efficacy of plyometric training for upper-extremity rehabilitation or performance enhancement. To measure upper-extremity kinematics and plyometric phase times before and after an 8-wk upper-extremity strength- and plyometric-training program. Randomized pretest-posttest design. Research laboratory. 40 recreationally active men (plyometric group, age 20.43 ± 1.40 y, height 180.00 ± 8.80 cm, weight 73.07 ± 7.21 kg; strength group, age 21.95 ± 3.40 y, height 173.98 ± 11.91 cm, weight 74.79 ± 13.55 kg). Participants were randomly assigned to either a strength-training group or a strength- and plyometric-training group. Each participant performed the assigned training for 8 wk. Dynamic and static glenohumeral and scapular-rotation measurements were taken before and after the training programs. Dynamic measurement of scapular rotation and time spent in each plyometric phase (concentric, eccentric, and amortization) during a ball-toss exercise were recorded while the subjects were fitted with an electromagnetic tracking system. Static measures included scapular upward rotation at 3 different glenohumeral-abduction angles, glenohumeral internal rotation, and glenohumeral external rotation. Posttesting showed that both groups significantly decreased the time spent in the amortization, concentric, and eccentric phases of a ball-toss exercise (P < .01). Both groups also exhibited significantly decreased static external rotation and increased dynamic scapular upward rotation after the training period (P < .01). The only difference between the training protocols was that the plyometric-training group exhibited an increase in internal rotation that was not present in the strength-training group (P < .01). These findings support the use of both upper-extremity plyometrics and strength training for reducing commonly identified upper-extremity-injury risk factors and improving upper-extremity performance.

A survey of internal medicine residents and faculty about the duration of attendings' inpatient rotations.

PubMed

Akl, Elie A; Maroun, Nancy; Klocke, Robert A; Schünemann, Holger J

2004-11-01

Some training programs are shortening the duration of attendings' rotations from 4 weeks to 2 weeks. Our objective was to determine the effect of 2-week inpatient rotation on self-reported impact on medical education, patient care practices, and faculty performance by internal medicine residents and teaching faculty. Cross-sectional study using an anonymous mailed and emailed survey. University-based internal medicine residency program in Buffalo, New York that recently introduced 2-week rotations. One hundred nineteen residents (99 responded, 83%) and 83 teaching faculty (76 responded, 92%). Perceived impact on medical education, patient care, and attending performance on 7-point Likert scales ranging from negative (-3) across neutral (0) to positive (+3) ratings. In general, residents and attendings felt that the short rotation negatively affects the attending's ability to evaluate residents and some aspects of patient care, but that it has no negative impact on residents' or medical students' learning. Attendings thought the 2-week rotation positively affects their private life and overall productivity. Subgroup analysis indicated that residents who graduated from U.S. medical schools were more pessimistic about the 2-week rotation compared to their international counterparts. Attendings who had completed at least one short rotation had consistently higher ratings of the 2-week rotation. Residents and attendings' perceptions suggest that the shorter attending inpatient rotation might have negative impact on medical education and patient care but positive effects on the attending's work productivity and private life. This tradeoff requires further evaluation including objective medical education and patient care outcomes.

Active heat exchange system development for latent heat thermal energy storage

NASA Technical Reports Server (NTRS)

Alario, J.; Kosson, R.; Haslett, R.

1980-01-01

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application (300 MW sub t storage for 6 hours). Two concepts were selected for hardware development: (1) a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and (2) a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which was nickel plated to decrease adhesion forces. In addition to improving performance by providing a nearly constant transfer rate during discharge, these active heat exchanger concepts were estimated to cost at least 25% less than the passive tube-shell design.

Scapular kinematic and shoulder muscle activity alterations after serratus anterior muscle fatigue.

PubMed

Umehara, Jun; Kusano, Ken; Nakamura, Masatoshi; Morishita, Katsuyuki; Nishishita, Satoru; Tanaka, Hiroki; Shimizu, Itsuroh; Ichihashi, Noriaki

2018-02-23

Although the serratus anterior muscle has an important role in scapular movement, no study to date has investigated the effect of serratus anterior fatigue on scapular kinematics and shoulder muscle activity. The purpose of this study was to clarify the effect of serratus anterior fatigue on scapular movement and shoulder muscle activity. The study participants were 16 healthy men. Electrical muscle stimulation was used to fatigue the serratus anterior muscle. Shoulder muscle strength and endurance, scapular movement, and muscle activity were measured before and after the fatigue task. The muscle activity of the serratus anterior, upper and lower trapezius, anterior and middle deltoid, and infraspinatus muscles was recorded, and the median power frequency of these muscles was calculated to examine the degree of muscle fatigue. The muscle endurance and median power frequency of the serratus anterior muscle decreased after the fatigue tasks, whereas the muscle activities of the serratus anterior, upper trapezius, and infraspinatus muscles increased. External rotation of the scapula at the shoulder elevated position increased after the fatigue task. Selective serratus anterior fatigue due to electric muscle stimulation decreased the serratus anterior endurance at the flexed shoulder position. Furthermore, the muscle activities of the serratus anterior, upper trapezius, and infraspinatus increased and the scapular external rotation was greater after serratus anterior fatigue. These results suggest that the rotator cuff and scapular muscle compensated to avoid the increase in internal rotation of the scapula caused by the dysfunction of the serratus anterior muscle. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Asymmetric pelvic and hip rotation in children with bilateral cerebral palsy: uni- or bilateral femoral derotation osteotomy?

PubMed

Niklasch, M; Döderlein, L; Klotz, M C; Braatz, F; Wolf, S I; Dreher, T

2015-02-01

Internal rotation gait is common among children with bilateral cerebral palsy. However, despite bilaterally increased femoral anteversion asymmetric internal rotation gait is often found. Femoral derotation osteotomy (FDO) is commonly performed bilaterally. Variable functional outcomes are reported especially in cases with mild internal hip rotation during gait and abnormal preoperative pelvic rotation. A major question is if a unilateral treatment of the more involved side in asymmetric cases leads to a comparable or even superior outcome. One hundred and nine children with spastic bilateral CP treated with FDO with pre- and 1-year postoperative 3D gait analysis were retrospectively collected. The asymmetry was calculated from the preoperative difference between both limbs in hip rotation obtained by 3D gait analysis. Twenty-eight children with asymmetry larger than 20° were selected and classified into two groups, according to whether they obtained a unilateral or bilateral FDO. Preoperative clinical examination and pre- and postoperative hip and pelvic rotation in gait analysis on the more and the less involved side did not differ significantly between both groups. Interestingly, in both groups, hip rotation did not change significantly in less-involved limbs, although intraoperative derotation averaged 25°. After unilateral FDO a significant change in pelvic rotation resulted, whereas this was not found after bilateral FDO. The results of this study suggest that unilateral FDO in children with asymmetric internal rotation gait leads to a comparable functional outcome compared to bilateral treatment. Furthermore, it was shown for the first time that considering the asymmetry has a positive effect on pelvic rotation. Copyright © 2015 Elsevier B.V. All rights reserved.

Gas Phase Conformations and Methyl Internal Rotation for 2-PHENYLETHYL Methyl Ether and its Argon Van Der Waals Complex from Fourier Transform Microwave Spectroscopy

NASA Astrophysics Data System (ADS)

Gurusinghe, Ranil M.; Tubergen, Michael

2015-06-01

A mini-cavity microwave spectrometer was used to record the rotational spectra arising from 2-phenylethyl methyl ether and its weakly bonded argon complex in the frequency range of 10.5 - 22 GHz. Rotational spectra were found for two stable conformations of the monomer: anti-anti and gauche-anti, which are 1.4 kJ mol-1 apart in energy at wB97XD/6-311++G(d,p) level. Doubled rotational transitions, arising from internal motion of the methyl group, were observed for both conformers. The program XIAM was used to fit the rotational constants, centrifugal distortion constants, and barrier to internal rotation to the measured transition frequencies of the A and E internal rotation states. The best global fit values of the rotational constants for the anti-anti conformer are A= 3799.066(3) MHz, B= 577.95180(17) MHz, C= 544.7325(3) MHz and the A state rotational constants of the gauche-anti conformer are A= 2676.1202(7) MHz, B= 760.77250(2) MHz, C= 684.78901(2) MHz. The rotational spectrum of 2-phenylethyl methyl ether - argon complex is consistent with the geometry where argon atom lies above the plane of the benzene moiety of gauche-anti conformer. Tunneling splittings were too small to resolve within experimental accuracy, likely due to an increase in three fold potential barrier when the argon complex is formed. Fitted rotational constants are A= 1061.23373(16) MHz, B= 699.81754(7) MHz, C= 518.33553(7) MHz. The lowest energy solvated ether - water complex with strong intermolecular hydrogen bonding has been identified theoretically. Progress on the assignment of the water complex will also be presented.

Rotational spectroscopy of antipyretics: Conformation, structure, and internal dynamics of phenazone

NASA Astrophysics Data System (ADS)

Écija, Patricia; Cocinero, Emilio J.; Lesarri, Alberto; Fernández, José A.; Caminati, Walther; Castaño, Fernando

2013-03-01

The conformational and structural preferences of phenazone (antipyrine), the prototype of non-opioid pyrazolone antipyretics, have been probed in a supersonic jet expansion using rotational spectroscopy. The conformational landscape of the two-ring assembly was first explored computationally, but only a single conformer was predicted, with the N-phenyl and N-methyl groups on opposite sides of the pyrazolone ring. Consistently, the microwave spectrum evidenced a rotational signature arising from a single molecular structure. The spectrum exhibited very complicated fine and hyperfine patterns (not resolvable with any other spectroscopic technique) originated by the simultaneous coupling of the methyl group internal rotation and the spins of the two 14N nuclei with the overall rotation. The internal rotation tunnelling was ascribed to the C-CH3 group and the barrier height established experimentally (7.13(10) kJ mol-1). The internal rotation of the N-CH3 group has a lower limit of 9.4 kJ mol-1. The structure of the molecule was determined from the rotational parameters, with the phenyl group elevated ca. 25° with respect to the average plane of the pyrazolic moiety and a phenyl torsion of ca. 52°. The origin of the conformational preferences is discussed in terms of the competition between intramolecular C-H⋯N and C-H⋯O weak hydrogen bonds.

Reflective practice and social responsibility in family medicine: Effect of performing an international rotation in a developing country.

PubMed

Loignon, Christine; Gottin, Thomas; Valois, Carol; Couturier, François; Williams, Robert; Roy, Pierre-Michel

2016-11-01

To explore the perceived effect of an elective international health rotation on family medicine resident learning. Qualitative, collaborative study based on semistructured interviews. Quebec. A sample of 12 family medicine residents and 9 rotation supervisors (N = 21). Semistructured interviews of residents and rotation supervisors. Residents and supervisors alike reported that their technical skills and relationship skills had benefited. All increased their knowledge of tropical pathologies and learned to expand their clinical examinations. They benefited from having very rich interactions in other care settings, working with vulnerable populations. The rotations had their greatest effect on relationship skills (communication, empathy, etc) and the ability to work with vulnerable patients. All of the participants were exposed to local therapies and local interpretations of disease symptoms and pathogenesis. The findings of this study will have a considerable effect on pedagogy. The residents' experiences of their international health rotations and what they learned in terms of medical skills and pedagogic approaches in working with patients are described. Using a collaborative approach with the rotation supervisors, the data were triangulated and the benefits of an international rotation on academic training were more accurately defined. The findings can now be used to enrich academic programs in social and preventive medicine and more adequately prepare future family physicians for work in various social and cultural settings. Copyright© the College of Family Physicians of Canada.

US Medical Student Performance on the NBME Subject Examination in Internal Medicine: Do Clerkship Sequence and Clerkship Length Matter?

PubMed

Ouyang, Wenli; Cuddy, Monica M; Swanson, David B

2015-09-01

Prior to graduation, US medical students are required to complete clinical clerkship rotations, most commonly in the specialty areas of family medicine, internal medicine, obstetrics and gynecology (ob/gyn), pediatrics, psychiatry, and surgery. Within a school, the sequence in which students complete these clerkships varies. In addition, the length of these rotations varies, both within a school for different clerkships and between schools for the same clerkship. The present study investigated the effects of clerkship sequence and length on performance on the National Board of Medical Examiner's subject examination in internal medicine. The study sample included 16,091 students from 67 US Liaison Committee on Medical Education (LCME)-accredited medical schools who graduated in 2012 or 2013. Student-level measures included first-attempt internal medicine subject examination scores, first-attempt USMLE Step 1 scores, and five dichotomous variables capturing whether or not students completed rotations in family medicine, ob/gyn, pediatrics, psychiatry, and surgery prior to taking the internal medicine rotation. School-level measures included clerkship length and average Step 1 score. Multilevel models with students nested in schools were estimated with internal medicine subject examination scores as the dependent measure. Step 1 scores and the five dichotomous variables were treated as student-level predictors. Internal medicine clerkship length and average Step 1 score were used to predict school-to-school variation in average internal medicine subject examination scores. Completion of rotations in surgery, pediatrics and family medicine prior to taking the internal medicine examination significantly improved scores, with the largest benefit observed for surgery (coefficient = 1.58 points; p value < 0.01); completion of rotations in ob/gyn and psychiatry were unrelated to internal medicine subject examination performance. At the school level, longer internal medicine clerkships were associated with higher scores on the internal medicine examination (coefficient = 0.23 points/week; p value < 0.01). The order in which students complete clinical clerkships and the length of the internal medicine clerkship are associated with their internal medicine subject examination scores. Findings may have implications for curriculum re-design.

Does Humeral Component Lateralization in Reverse Shoulder Arthroplasty Affect Rotator Cuff Torque? Evaluation in a Cadaver Model.

PubMed

Chan, Kevin; Langohr, G Daniel G; Mahaffy, Matthew; Johnson, James A; Athwal, George S

2017-10-01

Humeral component lateralization in reverse total shoulder arthroplasty (RTSA) may improve the biomechanical advantage of the rotator cuff, which could improve the torque generated by the rotator cuff and increase internal and external rotation of the shoulder. The purpose of this in vitro biomechanical study was to evaluate the effect of humeral component lateralization (or lateral offset) on the torque of the anterior and posterior rotator cuff. Eight fresh-frozen cadaveric shoulders from eight separate donors (74 ± 8 years; six males, two females) were tested using an in vitro simulator. All shoulders were prescreened for soft tissue deficit and/or deformity before testing. A custom RTSA prosthesis was implanted that allowed five levels of humeral component lateralization (15, 20, 25, 30, 35 mm), which avoided restrictions imposed by commercially available designs. The torques exerted by the anterior and posterior rotator cuff were measured three times and then averaged for varying humeral lateralization, abduction angle (0°, 45°, 90°), and internal and external rotation (-60°, -30°, 0°, 30°, 60°). A three-way repeated measures ANOVA (abduction angle, humeral lateralization, internal rotation and external rotation angles) with a significance level of α = 0.05 was used for statistical analysis. Humeral lateralization only affected posterior rotator cuff torque at 0° abduction, where increasing humeral lateralization from 15 to 35 mm at 60° internal rotation decreased external rotation torque by 1.6 ± 0.4 Nm (95% CI, -0.07 -1.56 Nm; p = 0.06) from 4.0 ± 0.3 Nm to 2.4 ± 0.6 Nm, respectively, but at 60° external rotation increased external rotation torque by 2.2 ± 0.5 Nm (95% CI, -4.2 to -0.2 Nm; p = 0.029) from 6.2 ± 0.5 Nm to 8.3 ± 0.5 Nm, respectively. Anterior cuff torque was affected by humeral lateralization in more arm positions than the posterior cuff, where increasing humeral lateralization from 15 to 35 mm when at 60° internal rotation increased internal rotation torque at 0°, 45°, and 90° abduction by 3.2 ± 0.5 Nm (95% CI, 1.1-5.2 Nm; p = 0.004) from 6.6 ± 0.6 Nm to 9.7 ± 0.6 Nm, 4.0 ± 0.3 Nm (95% CI, 2.8-5.0 Nm; p < 0.001) from 1.7 ± 1.0 Nm to 5.6 ± 0.9 Nm, and 2.2 ± 0.2 Nm (95% CI, 1.4-2.9 Nm; p < 0.001) from 0.6 ± 0.6 Nm to 2.8 ± 0.6 Nm, respectively. In neutral internal and external rotation, increasing humeral lateral offset from 15 to 35 mm increased the internal rotation torque at 45˚ and 90˚ abduction by 1.5 ± 0.3 Nm (95% CI, 0.2-2.7 Nm; p = 0.02) and 1.3 ± 0.2 Nm (95% CI, 0.4-2.3 Nm; p < 0.001), respectively. Humeral component lateralization improves rotator cuff torque. The results of this preliminary in vitro cadaveric study suggest that the lateral offset of the RTSA humeral component plays an important role in the torque generated by the anterior and posterior rotator cuff. However, further studies are needed before clinical application of these results. Increasing humeral offset may have adverse effects, such as the increased risk of implant modularity, increasing tension of the cuff and soft tissues, increased costs often associated with design modifications, and other possible as yet unforeseen negative consequences.

Generalization of the Activated Complex Theory of Reaction Rates. I. Quantum Mechanical Treatment

DOE R&D Accomplishments Database

Marcus, R. A.

1964-01-01

In its usual form activated complex theory assumes a quasi-equilibrium between reactants and activated complex, a separable reaction coordinate, a Cartesian reaction coordinate, and an absence of interaction of rotation with internal motion in the complex. In the present paper a rate expression is derived without introducing the Cartesian assumption. The expression bears a formal resemblance to the usual one and reduces to it when the added assumptions of the latter are introduced.

Intern underperformance is detected more frequently in emergency medicine rotations.

PubMed

Aram, Narelle; Brazil, Victoria; Davin, Lorna; Greenslade, Jaimi

2013-02-01

To determine the frequency and nature of intern underperformance as documented on in-training assessment forms. A retrospective review of intern assessment forms from a 2 year period (2009-2010) was conducted at a tertiary referral hospital in Brisbane, Queensland. The frequency of interns assessed as 'requiring substantial assistance' and/or 'requires further development' on mid- or end-of-term assessment forms was determined. Forms were analysed by the clinical rotation, time of year and domain(s) of clinical practice in which underperformance was documented. During 2009 and 2010 the overall documented incidence of intern underperformance was 2.4% (95% CI 1.5-3.9%). Clinical rotation in emergency medicine detected significantly more underperformance compared with other rotations (P < 0.01). Interns predominantly had difficulty with 'clinical judgment and decision-making skills', 'time management skills' and 'teamwork and colleagues' (62.5%, 55% and 32.5% of underperforming assessments, respectively). Time of the year did not affect frequency of underperformance. A proportion of 13.4% (95% CI 9.2-19.0%) of interns working at the institution over the study period received at least one assessment in which underperformance was documented. Seventy-six per cent of those interns who had underperformance identified by mid-term assessment successfully completed the term following remediation. The prevalence of underperformance among interns is low, although higher than previously suggested. Emergency medicine detects relatively more interns in difficulty than other rotations. © 2012 The Authors. EMA © 2012 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Intraplate Crustal Deformation Within the Northern Sinai Microplate: Evidence from Paleomagnetic Directions and Mechanical Modeling

NASA Astrophysics Data System (ADS)

Dembo, N.; Granot, R.; Hamiel, Y.

2017-12-01

The intraplate crustal deformation found in the northern part of the Sinai Microplate, located near the northern Dead Sea Fault plate boundary, is examined. Previous studies have suggested that distributed deformation in Lebanon is accommodated by regional uniform counterclockwise rigid block rotations. However, remanent magnetization directions observed near the Lebanese restraining bend are not entirely homogeneous suggesting that an unexplained and complex internal deformation pattern exists. In order to explain the variations in the amount of vertical-axis rotations we construct a mechanical model of the major active faults in the region that simulates the rotational deformation induced by motion along these faults. The rotational pattern calculated by the mechanical modeling predicts heterogeneous distribution of rotations around the faults. The combined rotation field that considers both the fault induced rotations and the already suggested regional block rotations stands in general agreement with the observed magnetization directions. Overall, the modeling results provide a more detailed and complete picture of the deformation pattern in this region and show that rotations induced by motion along the Dead Sea Fault act in parallel to rigid block rotations. Finally, the new modeling results unravel important insights as to the fashion in which crustal deformation is distributed within the northern part of the Sinai Microplate and propose an improved deformational mechanism that might be appropriate for other plate margins as well.

The rotational elements of Mars and its satellites

NASA Astrophysics Data System (ADS)

Jacobson, R. A.; Konopliv, A. S.; Park, R. S.; Folkner, W. M.

2018-03-01

The International Astronomical Union (IAU) defines planet and satellite coordinate systems relative to their axis of rotation and the angle about that axis. The rotational elements of the bodies are the right ascension and declination of the rotation axis in the International Celestial Reference Frame and the rotation angle, W, measured easterly along the body's equator. The IAU specifies the location of the body's prime meridian by providing a value for W at epoch J2000. We provide new trigonometric series representations of the rotational elements of Mars and its satellites, Phobos and Deimos. The series for Mars are from a least squares fit to the rotation model used to orient the Martian gravity field. The series for the satellites are from a least squares fit to rotation models developed in accordance with IAU conventions from recent ephemerides.

Interposition Dermal Matrix Xenografts: A Successful Alternative to Traditional Treatment of Massive Rotator Cuff Tears.

PubMed

Neumann, Julie A; Zgonis, Miltiadis H; Rickert, Kathleen D; Bradley, Kendall E; Kremen, Thomas J; Boggess, Blake R; Toth, Alison P

2017-05-01

Management of massive rotator cuff tears in shoulders without glenohumeral arthritis remains problematic for surgeons. Repairs of massive rotator cuff tears have failure rates of 20% to 94% at 1 to 2 years postoperatively as demonstrated with arthrography, ultrasound, and magnetic resonance imaging. Additionally, inconsistent outcomes have been reported with debridement alone of massive rotator cuff tears, and limitations have been seen with other current methods of operative intervention, including arthroplasty and tendon transfers. The use of interposition porcine acellular dermal matrix xenograft in patients with massive rotator cuff tears will result in improved subjective outcomes, postoperative pain, function, range of motion, and strength. Case series; Level of evidence, 4. Sixty patients (61 shoulders) were prospectively observed for a mean of 50.3 months (range, 24-63 months) after repair of massive rotator cuff tears with porcine acellular dermal matrix xenograft as an interposition graft. Subjective outcome data were obtained with visual analog scale for pain score (0-10, 0 = no pain) and Modified American Shoulder and Elbow Surgeons (MASES) score. Active range of motion in flexion, external rotation, and internal rotation were recorded. Strength in the supraspinatus and infraspinatus muscles was assessed manually on a 10-point scale and by handheld dynamometer. Ultrasound was used to assess the integrity of the repair during latest follow-up. Mean visual analog scale pain score decreased from 4.0 preoperatively to 1.0 postoperatively ( P < .001). Mean active forward flexion improved from 140.7° to 160.4° ( P < .001), external rotation at 0° of abduction from 55.6° to 70.1° ( P = .001), and internal rotation at 90° of abduction from 52.0° to 76.2° ( P < .001). Supraspinatus manual strength increased from 7.7 to 8.8 ( P < .001) and infraspinatus manual strength from 7.7 to 9.3 ( P < .001). Mean dynamometric strength in forward flexion was 77.7 N in nonoperative shoulders (shoulder that did not undergo surgery) and 67.8 N ( P < .001) in operative shoulders (shoulder that underwent rotator cuff repair with interposition porcine dermal matrix xenograft). Mean dynamometric strength in external rotation was 54.5 N in nonoperative shoulders and 50.1 N in operative shoulders ( P = .04). Average postoperative MASES score was 87.8. Musculoskeletal ultrasound showed that 91.8% (56 of 61) of repairs were fully intact; 3.3% (2 of 61), partially intact; and 4.9% (3 of 61), not intact. Patients who underwent repair of massive rotator cuff tears with interposition porcine acellular dermal matrix graft have good subjective function as assessed by the MASES score. Patients have significant improvement in pain, range of motion, and manual muscle strength. Postoperative ultrasound demonstrated that the repair was completely intact in 91.8% of patients, a vast improvement compared with results previously reported for primary repairs of massive rotator cuff tears.

Glenohumeral range of motion (ROM) and isometric strength of professional team handball athletes, part III: changes over the playing season.

PubMed

Fieseler, Georg; Jungermann, Philipp; Koke, Alexander; Irlenbusch, Lars; Delank, Karl-Stefan; Schwesig, René

2015-12-01

The aim of our study was to investigate the relation of workload on range of motion and isometric strength of team handball athletes' shoulders over a competitive season. 31 Professional male handball athletes underwent clinical shoulder examinations. Athletes were examined subsequently during the complete playing season (week 0, 6, 22 and 40) to determine bilateral isometric shoulder rotational strength and active range of motion (ROM). In addition, relative (intraclass correlation coefficients (ICC) and absolute (standard error of measurement) reliability were calculated. Intraobserver reliability was excellent (ICC 0.76-0.98) for isometric strength and flexibility measurements. Internal rotation (IR) and total arc ROM in the throwing shoulder (TS) decreased significantly (p < 0.05) in both sequences (week 22 to week 40, week 0 to week 40). External rotation (ER) ROM and isometric strength in IR and ER did not change significantly. Glenohumeral internal rotation deficit (GIRD) and external rotation gain (ERG) of the TS decreased significantly between week 22 and week 40, but both did not change overall (week 0 to week 40). There was significant influence on IR ROM (week 22 to week 40) and strength in ER (week 0 to week 40) in the non-throwing shoulder. Several characteristics of handball players' shoulders changed significantly from the beginning to the end of a season. More specifically, the repetitive forces accumulated during the competitive season resulted in altered GIRD, ERG and isometric strength of the dominant glenohumeral joint.

Gender differences in passive knee biomechanical properties in tibial rotation.

PubMed

Park, Hyung-Soon; Wilson, Nicole A; Zhang, Li-Qun

2008-07-01

The anterior cruciate ligament (ACL) is the most commonly injured knee ligament with the highest incidence of injury in female athletes who participate in pivoting sports. Noncontact ACL injuries commonly occur with both internal and external tibial rotation. ACL impingement against the lateral wall of the intercondylar notch during tibial external rotation and abduction has been proposed as an injury mechanism, but few studies have evaluated in vivo gender-specific differences in laxity and stiffness in external and internal tibial rotations. The purpose of this study was to evaluate these differences. The knees of 10 male and 10 female healthy subjects were rotated between internal and external tibial rotation with the knee at 60 degrees of flexion. Joint laxity, stiffness, and energy loss were compared between male and female subjects. Women had higher laxity (p = 0.01), lower stiffness (p = 0.038), and higher energy loss (p = 0.008) in external tibial rotation than did men. The results suggest that women may be at greater risk of ACL injury resulting from impingement against the lateral wall of the intercondylar notch, which has been shown to be associated with external tibial rotation and abduction.

Associations Among Hip and Shoulder Range of Motion and Shoulder Injury in Professional Baseball Players

PubMed Central

Scher, Steve; Anderson, Kyle; Weber, Nick; Bajorek, Jeff; Rand, Kevin; Bey, Michael J.

2010-01-01

Abstract Context: The overhead throwing motion is complex, and restrictions in range of motion (ROM) at the hip may place additional demands on the shoulder that lead to injury. However, the relationship between hip and shoulder ROM in athletes with and without a history of shoulder injury is unknown. Objective: To (1) determine if differences exist in hip and shoulder ROM between professional baseball players with a history of shoulder injury and those with no history of shoulder injury and (2) assess relationships between hip and shoulder ROM in these players. Design: Cross-sectional study. Patients or Other Participants: Fifty-seven professional baseball players. Main Outcome Measure(s): Outcome measures consisted of hip extension and internal rotation, shoulder internal and external rotation, glenohumeral internal-rotation deficit, and history of shoulder injury. Differences in shoulder and hip ROM were assessed with a 1-way analysis of variance. Associations between hip and shoulder ROM were assessed with linear regression. Results: Nonpitchers with a history of shoulder injury had more external rotation and less internal rotation of the shoulder than nonpitchers with no history of shoulder injury. Glenohumeral internal-rotation deficit was greater in both pitchers and nonpitchers with a history of shoulder injury. The relationship between dominant hip extension and shoulder external rotation was significant for pitchers with a history of shoulder injury and nonpitchers with a history of shoulder injury. Conclusions: Shoulder injury may be associated with specific measures of hip and shoulder ROM, and hip extension and shoulder external rotation may be related in baseball players with a history of shoulder injury. Additional research is necessary to understand the specific mechanisms of shoulder injury in the throwing athlete. PMID:20210623

Prospective multifactorial analysis of preseason risk factors for shoulder and elbow injuries in high school baseball pitchers.

PubMed

Shitara, Hitoshi; Kobayashi, Tsutomu; Yamamoto, Atsushi; Shimoyama, Daisuke; Ichinose, Tsuyoshi; Tajika, Tsuyoshi; Osawa, Toshihisa; Iizuka, Haku; Takagishi, Kenji

2017-10-01

To prospectively identify preseason physical factors for shoulder and elbow injuries during the season in high school baseball pitchers. The study included 105 high school baseball pitchers [median age 16 (15-17) years]. The range of motion of the shoulder (90° abducted external and internal rotation) and elbow (extension/flexion), shoulder muscle strength (abduction and prone internal and external rotation), shoulder and elbow laxity, horizontal flexion, and scapular dyskinesis were assessed. After the season, the participants completed questionnaires regarding shoulder and/or elbow injuries, with injury defined as an inability to play for ≥1 week due to elbow/shoulder problems. The results of two groups (injured and noninjured) were compared using t tests and Chi-square analyses. Stepwise forward logistic regression models were developed to identify risk factors. Twenty-one injuries were observed. In univariate analysis, 90° abducted internal rotation and total arc of the dominant shoulder and the ratio of prone external rotation in the dominant to nondominant sides in the injured group were significantly less than those in the noninjured group (P = 0.02, 0.04, and 0.01, respectively). In logistic regression analysis, 90° abducted internal rotation in the dominant shoulder and prone external rotation ratio were significantly associated with injuries (P = 0.02 and 0.03, respectively). A low prone external rotation ratio and decreased 90° abducted internal rotation in the dominant shoulder in the preseason were significant risk factors for shoulder and elbow injuries in high school baseball pitchers. The results may contribute to reduce the incidence of these injuries. II.

Biomechanical effect of latissimus dorsi tendon transfer for irreparable massive cuff tear.

PubMed

Oh, Joo Han; Tilan, Justin; Chen, Yu-Jen; Chung, Kyung Chil; McGarry, Michelle H; Lee, Thay Q

2013-02-01

The purpose of this study was to determine the biomechanical effects of latissimus dorsi transfer in a cadaveric model of massive posterosuperior rotator cuff tear. Eight cadaveric shoulders were tested at 0°, 30°, and 60° of abduction in the scapular plane with anatomically based muscle loading. Humeral rotational range of motion and the amount of humeral rotation due to muscle loading were measured. Glenohumeral kinematics and contact characteristics were measured throughout the range of motion. After testing in the intact condition, the supraspinatus and infraspinatus were resected. The cuff tear was then repaired by latissimus dorsi transfer. Two muscle loading conditions were applied after latissimus transfer to simulate increased tension that may occur due to limited muscle excursion. A repeated-measures analysis of variance was used for statistical analysis. The amount of internal rotation due to muscle loading and maximum internal rotation increased with massive cuff tear and was restored with latissimus transfer (P < .05). At maximum internal rotation, the humeral head apex shifted anteriorly, superiorly, and laterally at 0° of abduction after massive cuff tear (P < .05); this abnormal shift was corrected with latissimus transfer (P < .05). However, at 30° and 60° of abduction, latissimus transfer significantly altered kinematics (P < .05) and latissimus transfer with increased muscle loading increased contact pressure, especially at 60° of abduction. Latissimus dorsi transfer is beneficial in restoring humeral internal/external rotational range of motion, the internal/external rotational balance of the humerus, and glenohumeral kinematics at 0° of abduction. However, latissimus dorsi transfer with simulated limited excursion may lead to an overcompensation that can further deteriorate normal biomechanics, especially at higher abduction angles. Published by Mosby, Inc.

Influence of post-cam design of posterior stabilized knee prosthesis on tibiofemoral motion during high knee flexion.

PubMed

Lin, Kun-Jhih; Huang, Chang-Hung; Liu, Yu-Liang; Chen, Wen-Chuan; Chang, Tsung-Wei; Yang, Chan-Tsung; Lai, Yu-Shu; Cheng, Cheng-Kung

2011-10-01

The post-cam design of contemporary posterior stabilized knee prosthesis can be categorized into flat-on-flat or curve-on-curve contact surfaces. The curve-on-curve design has been demonstrated its advantage of reducing stress concentration when the knee sustained an anteroposterior force with tibial rotation. How the post-cam design affects knee kinematics is still unknown, particularly, to compare the difference between the two design features. Analyzing knee kinematics of posterior stabilized knee prosthesis with various post-cam designs should provide certain instructions to the modification of prosthesis design. A dynamic knee model was utilized to investigate tibiofemoral motion of various post-cam designs during high knee flexion. Two posterior stabilized knee models were constructed with flat-on-flat and curve-on-curve contact surfaces of post-cam. Dynamic data of axial tibial rotation and femoral translation were measured from full-extension to 135°. Internal tibial rotation increased with knee flexion in both designs. Before post-cam engagement, the magnitude of internal tibial rotation was close in the two designs. However, tibial rotation angle decreased beyond femoral cam engaged with tibial post. The rate of reduction of tibial rotation was relatively lower in the curve-on-curve design. From post-cam engagement to extreme flexion, the curve-on-curve design had greater internal tibial rotation. Motion constraint was generated by medial impingement of femoral cam on tibial post. It would interfere with the axial motion of the femur relative to the tibia, resulting in decrease of internal tibial rotation. Elimination of rotational constraint should be necessary for achieving better tibial rotation during high knee flexion. Copyright © 2011 Elsevier Ltd. All rights reserved.

SU-F-E-12: Elective International Rotations in Medical Physics Residency Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, D; Mundt, A; Einck, J

Purpose: The purpose of this educational program is to motivate talented, intelligent individuals to become stakeholders in the global effort to improve access to radiotherapy. Methods: The need to improve global access to radiotherapy has been clearly established and several organizations are making substantial progress in securing funding and developing plans to achieve this worthwhile goal. The incorporation of elective international rotations in residency programs may provide one possible mechanism to promote and support this future investment. We recently incorporated an elective 1-month international rotation into our CAMPEP accredited Medical Physics residency program, with our first rotation taking place inmore » Vietnam. A unique aspect of this rotation was that it was scheduled collaboratively with our Radiation Oncology residency program such that Radiation Oncology and Medical Physics residents traveled to the same clinic at the same time. Results: We believe the international rotation substantially enhances the educational experience, providing additional benefits to residents by increasing cross-disciplinary learning and offering a shared learning experience. The combined international rotation may also increase benefit to the host institution by modeling positive multidisciplinary working relationships between Radiation Oncologists and Medical Physicists. Our first resident returned with several ideas designed to improve radiotherapy in resource-limited settings – one of which is currently being pursued in collaboration with a vendor. Conclusion: The elective international rotation provides a unique learning experience that has the potential to motivate residents to become stakeholders in the global effort to improve access to radiotherapy. What better way to prepare the next generation of Medical Physicists to meet the challenges of improving global access to radiotherapy than to provide them with training experiences that motivate them to be socially conscious and equip them with the clinical and problem solving skills required to deliver effective treatments in resource limited settings?.« less

Ab initio SCF study of the barrier to internal rotation in simple amides. Part 3. Thioamides

NASA Astrophysics Data System (ADS)

Vassilev, Nikolay G.; Dimitrov, Valentin S.

2003-06-01

The free energies of activation for rotation about the thiocarbonyl C-N bond in X-C(S)N(CH 3) 2 (X=H, F, Cl, CH 3, CF 3) were calculated at the MP2(fc)/6-31+G*//6-31G* and MP2(fc)/6-311++G**//6-311++G** levels and compared with literature NMR gas-phase data. The results of calculations indicate that the nonbonded interactions in ground state (GS) are mainly responsible for the differences in the rotational barriers. For X=H, CH 3 and CF 3, the anti transition state (TS) is more stable; for the case X=Cl, the syn TS is more stable, while for the X=F, the two TS are energetically almost equivalent.

ACUTE CHANGES IN PASSIVE GLENOHUMERAL ROTATION FOLLOWING TENNIS PLAY EXPOSURE IN ELITE FEMALE PLAYERS

PubMed Central

Kibler, W. Ben; Myers, Natalie L.; Smith, Belinda J.

2016-01-01

Background Alterations in glenohumeral (GH) rotation especially internal rotation and total range of motion have been associated with altered GH kinematics and susceptibility to injury. Researchers have evaluated long-term change in baseball and tennis players, and short-term changes in baseball players. However, acute (short-term) changes in GH rotation have not been evaluated in tennis players. Hypotheses/Purpose The purpose of this study was to quantify short-term glenohumeral rotational changes within a group of professional women's tennis players following competitive play. It was hypothesized that there would be acute alterations in passive glenohumeral internal rotation and total range of motion following episodes of tennis play. Study Design Cohort Study Methods Passive glenohumeral external rotation (GER), glenohumeral internal rotation (GIR), and total range of motion (TROM) were evaluated in a cohort of 79 professional adult female tennis players. Measurements were taken at three different time points (TP): baseline before match play (TP1), immediately after match play (TP2), and 24-hours after baseline (TP3). Results There was a statistically significant decrease in the mean GIR from TP1 (43 ± 11 °) to TP2 (39 ± 9 °) (p=0.002) and from TP1 to TP3 (38 ± 10 °) (p=0.001). All measures were at the level of minimal detectable change (MDC) (4 °) indicating clinical significance. There was a decrease in mean TROM from TP1 (146 ± 11 °) to TP2 (142 ± 12 °) (p=0.04), which was not above MDC (7 °). Subgroup analysis showed that 47% of the players demonstrated a decrease in GIR beyond MDC, and 37% demonstrated a decrease in TROM beyond MDC. GER remained unchanged across all time points (p>0.05). Conclusion Both GIR and TROM were reduced after acute exposure to tennis play. In a large subgroup of the cohort, the changes were clinically significant and approached values previously demonstrated to be associated with increased injury risk. Given the changes in glenohumeral motion following acute exposure to tennis, evaluation of players for significant motion alterations following overhead activity and intervention strategies to minimize such alterations in these players are recommended for high level tennis players. Level of evidence Level 3 PMID:27104056

The Relationship Between Maximum Isometric Strength and Ball Velocity in the Tennis Serve.

PubMed

Baiget, Ernest; Corbi, Francisco; Fuentes, Juan Pedro; Fernández-Fernández, Jaime

2016-12-01

The aims of this study were to analyze the relationship between maximum isometric strength levels in different upper and lower limb joints and serve velocity in competitive tennis players as well as to develop a prediction model based on this information. Twelve male competitive tennis players (mean ± SD; age: 17.2 ± 1.0 years; body height: 180.1 ± 6.2 cm; body mass: 71.9 ± 5.6 kg) were tested using maximum isometric strength levels (i.e., wrist, elbow and shoulder flexion and extension; leg and back extension; shoulder external and internal rotation). Serve velocity was measured using a radar gun. Results showed a strong positive relationship between serve velocity and shoulder internal rotation (r = 0.67; p < 0.05). Low to moderate correlations were also found between serve velocity and wrist, elbow and shoulder flexion - extension, leg and back extension and shoulder external rotation (r = 0.36 - 0.53; p = 0.377 - 0.054). Bivariate and multivariate models for predicting serve velocity were developed, with shoulder flexion and internal rotation explaining 55% of the variance in serve velocity (r = 0.74; p < 0.001). The maximum isometric strength level in shoulder internal rotation was strongly related to serve velocity, and a large part of the variability in serve velocity was explained by the maximum isometric strength levels in shoulder internal rotation and shoulder flexion.

Internal impingement in the etiology of rotator cuff tendinosis revisited.

PubMed

Budoff, Jeffrey E; Nirschl, Robert P; Ilahi, Omer A; Rodin, Dennis M

2003-10-01

The theory of internal impingement holds that, in overhead athletes, repeated contact between the undersurface of the rotator cuff and the posterosuperior glenoid rim leads to articular-sided partial-thickness rotator cuff tears and superior labral lesions. However, we have noted this same constellation of lesions in our general patient population. These recreational athletic patients do not routinely assume the position of extreme abduction and external rotation, and thus are unlikely to experience significant internal impingement forces. The goal of this study was to document the prevalence of superior labral lesions in patients being treated for partial-thickness undersurface rotator cuff tears. Retrospective case series. We retrospectively reviewed the records of 75 shoulders arthroscopically treated for partial-thickness articular-sided rotator cuff tears. With the exception of one professional tennis player, no patients were playing sports at a professional or major college level. No professional or collegiate throwing athletes were included. The prevalence of these lesions and their association with recreational athletics was noted. We found that 55 of 75 (73.3%) shoulders with articular-sided partial-thickness rotator cuff tears also had superior labral lesions. A statistically significant increased prevalence of superior labral lesions in the dominant shoulder was seen (P =.03). In addition, our patients who engaged in overhand throwing had significantly fewer superior labral lesions in the dominant shoulders than did nonthrowers (P =.017). The "kissing lesions" of undersurface rotator cuff tears and posterosuperior labral damage may be explained by mechanisms other than "internal impingement."

The Optimal Forest Rotation: A Discussion and Annotated Bibliography

Treesearch

David H. Newman

1988-01-01

The literature contains six different criteria of the optimal forest rotation: (1) maximum single-rotation physical yield, (2) maximum single-rotation annual yield, (3) maximum single-rotation discounted net revenues, (4) maximum discounted net revenues from an infinite series of rotations, (5) maximum annual net revenues, and (6) maximum internal rate of return. First...

Three-dimensional analysis of the shoulder motion in patients with massive irreparable cuff tears after latissimus dorsi tendon transfer (LDT).

PubMed

Ippolito, Giorgio; Serrao, Mariano; Napoli, Francesco; Conte, Carmela; Miscusi, Massimo; Coppola, Gianluca; Pierelli, Francesco; Costanzo, Giuseppe; De Cupis, Vincenzo

2016-10-01

Latissimus dorsi tendon transfer (LDT) is a recent method for surgical treatment of massive, irreparable posterosuperior cuff tears (MIPCT). So far, there are no studies on the quantitative motion analysis of the shoulder and latissimus dorsi (LD) muscle activation after LDT. The changes in shoulder movements after LDT can be objectively assessed by the 3-D motion analysis. These changes may not be due to an increased activity of the LD muscle as external rotator. The shoulder kinematics of nine patients with MIPCT were recorded through a 3-D motion analysis system, before LTD (T0), and after 3 (T1) and 6 (T2) months post-LDT. Maximal shoulder flexion-extension, abduction-adduction, and horizontal abduction-adduction, and the internal and external circumduction of the shoulder joint were measured during upright standing posture. Surface EMG activity of the LD muscle was recorded during both internal rotation (IR) and external rotation (ER) tasks in three different postures. A significant increase of shoulder movements was observed at T2 compared with T0 for almost all motor tasks. A significant effect of LDT was also found on LD-IR/ER ratio in posture 1 at T2 compared with T0 and T1. No significant effects were found for the LD-IR/ER ratio in the other postures. Our study indicates that LDT is effective in shoulder motion recovery. Such improvement is not associated with a change in function of the LD muscle, which may be induced by a depression of the humeral head into the glenoid cavity instead.

Isokinetic evaluation of internal/external tibial rotation strength after the use of hamstring tendons for anterior cruciate ligament reconstruction.

PubMed

Armour, Tanya; Forwell, Lorie; Litchfield, Robert; Kirkley, Alexandra; Amendola, Ned; Fowler, Peter J

2004-01-01

Evaluation of the knee after an anterior cruciate ligament reconstruction with the use of the semitendinosus and gracilis (hamstring) autografts has primarily focused on flexion and extension strength. The semitendinosus and gracilis muscles contribute to internal tibial rotation, and it has been suggested that harvest of these tendons for the purpose of an anterior cruciate ligament reconstruction contributes to internal tibial rotation weakness. Internal tibial rotation strength may be affected by the semitendinosus and gracilis harvest after anterior cruciate ligament reconstruction. Prospective evaluation of internal and external tibial rotation strength. Inclusion criteria for subjects (N = 30): unilateral anterior cruciate ligament reconstruction at least 2 years previously, a stable anterior cruciate ligament (<5-mm side-to-side difference) at time of testing confirmed by surgeon and KT-1000 arthrometer, no history of knee problems after initial knee reconstruction, a normal contralateral knee, and the ability to comply with the testing protocol. In an attempt to minimize unwanted subtalar joint motion, subjects were immobilized using an ankle brace and tested at angular velocities of 60 degrees /s, 120 degrees /s, and 180 degrees /s at a knee flexion angle of 90 degrees . The mean peak torque measurements for internal rotation strength of the operative limb (60 degrees /s, 17.4 +/- 4.5 ft-lb; 120 degrees /s, 13.9 +/- 3.3 ft-lb; 180 degrees /s, 11.6 +/- 3.0 ft-lb) were statistically different compared to the nonoperated limb (60 degrees /s, 20.5 +/- 4.7 ft-lb; 120 degrees /s, 15.9 +/- 3.8 ft-lb; 180 degrees /s, 13.4 +/- 3.8 ft-lb) at 60 degrees /s (P = .012), 120 degrees /s (P = .036), and 180 degrees /s (P = .045). The nonoperative limb demonstrated greater strength at all speeds. The mean torque measurements for external rotation were statistically similar when compared to the nonoperated limb at all angular velocities. We have shown through our study that patients who undergo surgical intervention to repair a torn anterior cruciate ligament with the use of autogenous hamstring tendons demonstrate with weaker internal tibial rotation postoperatively at 2 years when compared to the contralateral limb.

Influence of glenoid component design and humeral component retroversion on internal and external rotation in reverse shoulder arthroplasty: a cadaver study.

PubMed

Berhouet, J; Garaud, P; Favard, L

2013-12-01

A common disadvantage of reverse shoulder arthroplasty is limitation of the range of arm rotation. Several changes to the prosthesis design and implantation technique have been suggested to improve rotation range of motion (ROM). Glenoid component design and degree of humeral component retroversion influence rotation ROM after reverse shoulder arthroplasty. The Aequalis Reversed™ shoulder prosthesis (Tornier Inc., Edina, MN, USA) was implanted into 40 cadaver shoulders. Eight glenoid component combinations were tested, five with the 36-mm sphere (centred seating, eccentric seating, inferior tilt, centred with a 5-mm thick lateralised spacer, and centred with a 7-mm thick lateralised spacer) and three with the 42-mm sphere (centred with no spacer or with a 7-mm or 10-mm spacer). Humeral component position was evaluated with 0°, 10°, 20°, 30°, and 40° of retroversion. External and internal rotation ROMs to posterior and anterior impingement on the scapular neck were measured with the arm in 20° of abduction. The large glenosphere (42 mm) was associated with significantly (P<0.05) greater rotation ROMs, particularly when combined with a lateralised spacer (46° internal and 66° external rotation). Rotation ROMs were smallest with the 36-mm sphere. Greater humeral component retroversion was associated with a decrease in internal rotation and a significant increase (P<0.05) in external rotation. The best balance between rotation ROMs was obtained with the native retroversion, which was estimated at 17.5° on average in this study. Our anatomic study in a large number of cadavers involved a detailed and reproducible experimental protocol. However, we did not evaluate the variability in scapular anatomy. Earlier studies of the influence of technical parameters did not take humeral component retroversion into account. In addition, no previous studies assessed rotation ROMs. Rotation ROM should be improved by the use of a large-diameter glenosphere with a spacer to lateralise the centre of rotation of the gleno-humeral joint, as well as by positioning the humeral component at the patient's native retroversion value. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Continuous distal migration and internal rotation of the C-stem prosthesis without any adverse clinical effects: an RSA study of 33 primary total hip arthroplasties followed for up to ten years.

PubMed

von Schewelov, T; Carlsson, A; Sanzén, L; Besjakov, J

2014-05-01

In 2005, we demonstrated that the polished triple-tapered C-stem at two years had migrated distally and rotated internally. From that series, 33 patients have now been followed radiologically, clinically and by radiostereometric analysis (RSA) for up to ten years. The distal migration within the cement mantle had continued and reached a mean of 2 mm (0.5 to 4.0) at ten years. Internal rotation, also within the cement mantle, was a mean 3.8° (external 1.6° to internal 6.6°) The cement mantle did not show any sign of migration or loosening in relation to the femoral bone. There were no clinical or radiological signs indicating that the migration or rotation within the cement mantle had had any adverse effects for the patients.

Effectiveness of Hip External Rotator Strengthening Exercise in Korean Postural Bowleg Women.

PubMed

Park, Seong Hoon; Lee, Jun Won; Kim, Joo Hyun; Tak, Kyoung Seok; Lee, Byeong Ho; Suh, In Suck

2017-08-01

Postural bowleg is a subclinical entity with both aesthetic and functional outcomes and appears to be common in East Asian countries. Internal rotation of the hip joint is associated with varus alignment at the knee joint of the bowleg. Strengthening exercise for the hip external rotator muscles seems to be effective in improving varus alignment of bowleg, but no standardized exercise program exists. A standardized active resistance strengthening exercise for hip external rotator muscles could improve varus alignment of the lower limb in bowlegged Korean women. In this article, a case series study was conducted to observe changes following a standardized 3-month program using equipment designed for strengthening of the hip external rotator muscles. Photogrammetric and radiographic data were used to compare the gap between knees and tibiofemoral (TF) angles before and after the exercise program. As a result, on average, the knee gap decreased by 1.6 cm. The TF angle decreased by 1.5°. Regression analysis revealed a statistically significant association between changes in knee gap and TF angle. The standardized 3-month active resistance strengthening exercise program of hip external rotator muscles was effective in improving postural deviation and cosmetic outcomes in bowlegged Korean women. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Methyl Group Internal Rotation in the Pure Rotational Spectrum of 1,1-DIFLUOROACETONE

NASA Astrophysics Data System (ADS)

Grubbs, G. S. Grubbs, II; Cooke, S. A.; Groner, P.

2011-06-01

We have used chirped pulse Fourier transform microwave spectroscopy to record the pure rotational spectrum of the title molecule. The spectrum was doubled owing to the internal rotation of the methyl group. The spectrum has been assigned and two approaches to the spectral analysis have been performed. In the first case, the A and E components were fit separately using a principal axis method with the SPFIT code of Pickett. In the second case, the A and E states were fit simultaneously using the ERHAM code. For a satisfactory analysis of the spectral data it has been found that the choice of Hamiltonian reduction, i.e. Watson A or S, is very important. The barrier to the internal rotation has been determined to be 261.1(8) Cm-1 and it will be compared to that of acetone and other halogenated acetone species recently studied in our laboratory.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boros, Eszter; Srinivas, Raja; Kim, Hee -Kyung

Aqua ligands can undergo rapid internal rotation about the M-O bond. For magnetic resonance contrast agents, this rotation results in diminished relaxivity. Herein, we show that an intramolecular hydrogen bond to the aqua ligand can reduce this internal rotation and increase relaxivity. Molecular modeling was used to design a series of four Gd complexes capable of forming an intramolecular H-bond to the coordinated water ligand, and these complexes had anomalously high relaxivities compared to similar complexes lacking a H-bond acceptor. Molecular dynamics simulations supported the formation of a stable intramolecular H-bond, while alternative hypotheses that could explain the higher relaxivitymore » were systematically ruled out. Finally, intramolecular H-bonding represents a useful strategy to limit internal water rotational motion and increase relaxivity of Gd complexes.« less

Multigrid Computations of 3-D Incompressible Internal and External Viscous Rotating Flows

NASA Technical Reports Server (NTRS)

Sheng, Chunhua; Taylor, Lafayette K.; Chen, Jen-Ping; Jiang, Min-Yee; Whitfield, David L.

1996-01-01

This report presents multigrid methods for solving the 3-D incompressible viscous rotating flows in a NASA low-speed centrifugal compressor and a marine propeller 4119. Numerical formulations are given in both the rotating reference frame and the absolute frame. Comparisons are made for the accuracy, efficiency, and robustness between the steady-state scheme and the time-accurate scheme for simulating viscous rotating flows for complex internal and external flow applications. Prospects for further increase in efficiency and accuracy of unsteady time-accurate computations are discussed.

Asteroseismology of Red-Giant Stars: Mixed Modes, Differential Rotation, and Eccentric Binaries

NASA Astrophysics Data System (ADS)

Beck, Paul G.

2013-12-01

Astronomers are aware of rotation in stars since Galileo Galilei attributed the movement of sunspots to rotation of the Sun in 1613. In contrast to the Sun, whose surface can be resolved by small telescopes or even the (protected) eye, we detect stars as point sources with no spatial information. Numerous techniques have been developed to derive information about stellar rotation. Unfortunately, most observational data allow only for the surface rotational rate to be inferred. The internal rotational profile, which has a great effect on the stellar structure and evolution, remains hidden below the top layers of the star - the essential is hidden to the eyes. Asteroseismology allows us to "sense" indirectly deep below the stellar surface. Oscillations that propagate through the star provide information about the deep stellar interiors while they also distort the stellar surface in characteristic patterns leading to detectable brightness or velocity variations. Also, certain oscillation modes are sensitive to internal rotation and carry information on how the star is spinning deep inside. Thanks to the unprecedented quality of NASA's space telescope Kepler, numerous detailed observations of stars in various evolutionary stages are available. Such high quality data allow that for many stars, rotation can not only be constrained from surface rotation, but also investigated through seismic studies. The work presented in this thesis focuses on the oscillations and internal rotational gradient of evolved single and binary stars. It is shown that the seismic analysis can reach the cores of oscillating red-giant stars and that these cores are rapidly rotating, while nested in a slowly rotating convective envelope.

Long-term outcomes of external femoral derotation osteotomies in children with cerebral palsy.

PubMed

Õunpuu, Sylvia; Solomito, Matthew; Bell, Katharine; Pierz, Kristan

2017-07-01

External femoral derotation osteotomy (FDO) is an orthopaedic intervention to correct increased femoral anteversion and associated excessive internal hip rotation and internal foot progression during gait in children with cerebral palsy. The resulting functional issues may include clearance problems and hip abductor lever-arm dysfunction. The purpose of this study was to evaluate long-term gait outcomes of FDO. Twenty ambulatory patients (27 sides) with cerebral palsy who underwent pre-operative (P0) and a one year post-operative (P1) gait analysis as part of the standard of care had a second post-operative analysis (P2) approximately 11 years post-surgical intervention. Mean hip rotation in stance showed statistically significant decreases in internal rotation at P1 post-surgical intervention that were maintained long-term (mean hip rotation P0: 21±9, P1: 0±9 and P2: 6±12 degrees internal). Similar results were seen with mean foot progression (P0: 9±16 degrees internal, P1: 14±13 degrees external, P2: 13±16 degrees external). However, 2/27 sides (9%) showed a recurrence of internal hip rotation of >15° at the 11year follow-up. The reasons for this recurrence could include age, surgical location and ongoing disease process all of which need to be further examined. We conclude that FDO can show long-term kinematic and functional benefits when performed in the prepubescent child with cerebral palsy in comparison to the natural progression of of hip rotation in cerebral palsy. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of foot landing position on biomechanical risk factors associated with anterior cruciate ligament injury.

PubMed

Tran, Andrew A; Gatewood, Corey; Harris, Alex H S; Thompson, Julie A; Dragoo, Jason L

2016-12-01

Identification of biomechanical risk factors associated with anterior cruciate ligament (ACL) injury can facilitate injury prevention. The purpose of this study is to investigate the effects of three foot landing positions, "toe-in", "toe-out" and "neutral", on biomechanical risk factors for ACL injury in males and females. The authors hypothesize that 1) relative to neutral, the toe-in position increases the biomechanical risk factors for ACL injury, 2) the toe-out position decreases these biomechanical risk factors, and 3) compared to males, females demonstrate greater changes in lower extremity biomechanics with changes in foot landing position. Motion capture data on ten male and ten female volunteers aged 20-30 years (26.4 ± 2.50) were collected during double-leg jump landing activities. Subjects were asked to land on force plates and target one of three pre-templated foot landing positions: 0° ("neutral"), 30° internal rotation ("toe-in"), and 30° external rotation ("toe-out") along the axis of the anatomical sagittal plane. A mixed-effects ANOVA and pairwise Tukey post-hoc comparison were used to detect differences in kinematic and kinetic variables associated with biomechanical risk factors of ACL injury between the three foot landing positions. Relative to neutral, landing in the toe-in position increased peak hip adduction, knee internal rotation angles and moments (p < 0.01), and peak knee abduction angle (p < 0.001). Landing in the toe-in position also decreased peak hip flexion angle (p < 0.001) and knee flexion angle (p = 0.023). Landing in the toe-out position decreased peak hip adduction, knee abduction, and knee internal rotation angles (all p < 0.001). Male sex was associated with a smaller increase in hip adduction moment (p = 0.043) and knee internal rotation moment (p = 0.032) with toe-in landing position compared with female sex. Toe-in landing position exacerbates biomechanical risk factors associated with ACL injury, while toe-out landing position decreases these factors.

Shortening the Miles to the Milestones: Connecting EPA-Based Evaluations to ACGME Milestone Reports for Internal Medicine Residency Programs.

PubMed

Choe, John H; Knight, Christopher L; Stiling, Rebekah; Corning, Kelli; Lock, Keli; Steinberg, Kenneth P

2016-07-01

The Next Accreditation System requires internal medicine training programs to provide the Accreditation Council for Graduate Medical Education (ACGME) with semiannual information about each resident's progress in 22 subcompetency domains. Evaluation of resident "trustworthiness" in performing entrustable professional activities (EPAs) may offer a more tangible assessment construct than evaluations based on expectations of usual progression toward competence. However, translating results from EPA-based evaluations into ACGME milestone progress reports has proven to be challenging because the constructs that underlay these two systems differ.The authors describe a process to bridge the gap between rotation-specific EPA-based evaluations and ACGME milestone reporting. Developed at the University of Washington in 2012 and 2013, this method involves mapping EPA-based evaluation responses to "milestone elements," the narrative descriptions within the columns of each of the 22 internal medicine subcompetencies. As faculty members complete EPA-based evaluations, the mapped milestone elements are automatically marked as "confirmed." Programs can maintain a database that tallies the number of times each milestone element is confirmed for a resident; these data can be used to produce graphical displays of resident progress along the internal medicine milestones.Using this count of milestone elements allows programs to bridge the gap between faculty assessments of residents based on rotation-specific observed activities and semiannual ACGME reports based on the internal medicine milestones. Although potentially useful for all programs, this method is especially beneficial to large programs where clinical competency committee members may not have the opportunity for direct observation of all residents.

42 CFR 57.2209 - Conditions of scholarship grant.

Code of Federal Regulations, 2011 CFR

2011-10-01

... internal medicine, rotating internships with an emphasis on pediatrics, rotating internships with an... pediatrics and straight internships in obstetrics and gynecology; Provided, That such internships are... internal medicine, general pediatrics and general obstetrics and gynecology; Provided, That such...

42 CFR 57.2209 - Conditions of scholarship grant.

Code of Federal Regulations, 2010 CFR

2010-10-01

... internal medicine, rotating internships with an emphasis on pediatrics, rotating internships with an... pediatrics and straight internships in obstetrics and gynecology; Provided, That such internships are... internal medicine, general pediatrics and general obstetrics and gynecology; Provided, That such...

Realization of ETRF2000 as a New Terrestrial Reference Frame in Republic of Serbia

NASA Astrophysics Data System (ADS)

Blagojevic, D.; Vasilic, V.

2012-12-01

The International Earth Rotation and Reference Systems Service (IERS) is a joint service of the International Association of Geodesy (IAG) and the International Astronomical Union (IAU), which provides the scientific community with the means for computing the transformation from the International Celestial Reference System (ICRS) to the International Terrestrial Reference System (ITRS). It further maintains the realizations of these systems by appropriate coordinate sets called "frames". The densification of terrestrial frame usually serves as official frame for positioning and navigation tasks within the territory of particular country. One of these densifications was recently performed in order to establish new reference frame for Republic of Serbia. The paper describes related activities resulting in ETRF2000 as a new Serbian terrestrial reference frame.

Knee rotation influences the femoral tunnel angle measurement after anterior cruciate ligament reconstruction: a 3-dimensional computed tomography model study

PubMed Central

Tang, Jing; Thorhauer, Eric; Marsh, Chelsea; Fu, Freddie H.

2013-01-01

Purpose Femoral tunnel angle (FTA) has been proposed as a metric for evaluating whether ACL reconstruction was performed anatomically. In clinic, radiographic images are typically acquired with an uncertain amount of internal/external knee rotation. The extent to which knee rotation will influence FTA measurement is unclear. Furthermore, differences in FTA measurement between the two common positions (0° and 45° knee flexion) have not been established. The purpose of this study was to investigate the influence of knee rotation on FTA measurement after ACL reconstruction. Methods Knee CT data from 16 subjects were segmented to produce 3D bone models. Central axes of tunnels were identified. The 0° and 45° flexion angles were simulated. Knee internal/external rotations were simulated in a range of ±20°. FTA was defined as the angle between the tunnel axis and femoral shaft axis, orthogonally projected into the coronal plane. Results Femoral tunnel angle was positively/negatively correlated with knee rotation angle at 0°/45° knee flexion. At 0° knee flexion, FTA for anterio-medial (AM) tunnels was significantly decreased at 20° of external knee rotation. At 45° knee flexion, more than 16° external or 19° internal rotation significantly altered FTA measurements for single-bundle tunnels; smaller rotations (±9° for AM, ±5° for PL) created significant errors in FTA measurements after double-bundle reconstruction. Conclusion Femoral tunnel angle measurements were correlated with knee rotation. Relatively small imaging malalignment introduced significant errors with knee flexed 45°. This study supports using the 0° flexion position for knee radiographs to reduce errors in FTA measurement due to knee internal/external rotation. Level of evidence Case–control study, Level III. PMID:23589127

Impact of Posterior Wear on Muscle Length with Reverse Shoulder Arthroplasty.

PubMed

Roche, Christopher P; Diep, Phong; Hamilton, Matthew A; Wright, Thomas W; Flurin, Pierre-Henri; Zuckerman, Joseph D; Routman, Howard D

2015-12-01

The use of reverse total shoulder arthroplasty (rTSA) in patients with posterior glenoid wear can be challenging. Implanting a baseplate in the correct version may require significant eccentric reaming, which further medializes the joint line and results in greater rotator cuff muscle shortening. To restore the joint line, bone graft may be required, though it is associated with additional risks. As an alternative solution, augmented glenoid baseplates offer the potential to restore the joint line and improve rotator cuff muscle tensioning without the need for eccentric reaming or supplemental bone graft. To that end, this computer analysis quantifies the rotator cuff muscle length for standard and augmented rTSA when used in a normal and posteriorly worn glenoid. These results demonstrate that shortening of the rotator cuff occurred for both the standard and posterior augmented reverse shoulder designs with additional muscle shortening occurring in scapula with posteriorly worn glenoids. More anatomic rotator cuff muscle tensioning was observed with augmented glenoid baseplates. The use of posterior augmented glenoid baseplates has the potential to improve stability and better restore active internal and external rotation, a current limitation of rTSA. However, clinical follow-up is necessary to confirm these favorable biomechanical results.

Low edge safety factor operation and passive disruption avoidance in current carrying plasmas by the addition of stellarator rotational transform

NASA Astrophysics Data System (ADS)

Pandya, M. D.; ArchMiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Knowlton, S. F.; Ma, X.; Massidda, S.; Maurer, D. A.; Roberds, N. A.; Traverso, P. J.

2015-11-01

Low edge safety factor operation at a value less than two ( q (a )=1 /ι̷tot(a )<2 ) is routine on the Compact Toroidal Hybrid device with the addition of sufficient external rotational transform. Presently, the operational space of this current carrying stellarator extends down to q (a )=1.2 without significant n = 1 kink mode activity after the initial plasma current rise phase of the discharge. The disruption dynamics of these low edge safety factor plasmas depend upon the fraction of helical field rotational transform from external stellarator coils to that generated by the plasma current. We observe that with approximately 10% of the total rotational transform supplied by the stellarator coils, low edge q disruptions are passively suppressed and avoided even though q(a) < 2. When the plasma does disrupt, the instability precursors measured and implicated as the cause are internal tearing modes with poloidal, m, and toroidal, n, helical mode numbers of m /n =3 /2 and 4/3 observed on external magnetic sensors and m /n =1 /1 activity observed on core soft x-ray emissivity measurements. Even though the edge safety factor passes through and becomes much less than q(a) < 2, external n = 1 kink mode activity does not appear to play a significant role in the disruption phenomenology observed.

Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task.

PubMed

Meinerz, Carolyn M; Malloy, Philip; Geiser, Christopher F; Kipp, Kristof

2015-09-01

Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions. To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task. Controlled laboratory study. University biomechanics laboratory. Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg). Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions. Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles. Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases. Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition.

Use of the concept mapping in teaching during a medical rotation of interns: an exploratory study.

PubMed

Kwas, Hamida; Ghédira, Habib

2017-12-01

Concept mapping is an excellent learning toolallowing to stimulate active learning.For this reason, the concept mapping is currently used increasingly in the medical and paramedical field. The aim of our study is to determine the contribution of teaching of medical interns by the concept mapping. Fourteen students enrolled at the same time in a medical rotation in Pulmonology were recruited for this exploratory study. Interns are divided into two groups (A and B).Both groups are taught by the clinical case method, illustrated by a concept mapping for group A interns. The evolution of the knowledge accuracy at post-testing has been greater in the group taught by the method of concept mapping: the number of correct responses increased in all participants of group A versus only 4 of group B. All students taught by concept mapping had at the post-test a note higher than or equal to 10/20 versus only three of the group taught by the method without concept map. The average score was 13 (11-15) in group A versus 10.28 (6-14) in group B. We emphasize the use of concept mapping in teaching especially in the faculty of medicine and we encourage clinicians to use this method in teaching interns in the hospital.

Real Research In The Classroom - Solar Active Longitudes

NASA Astrophysics Data System (ADS)

Stagg, T.; Gearen, M.; Jacoby, S. H.; Jones, H. P.; Henney, C. J.; Hill, F.

2000-12-01

We present a high-school level educational/research module for a project that improves computer and analytical skills and contributes new scientific results to the field of solar astronomy and physics. The module has been developed within the RET (Research Experience for Teachers) program as a new application of a cooperative project between the RBSE (Research-Based Science Education) initiative of the NSF and the NASA Education/Public Outreach program. The research goal is to improve our knowledge of the characteristics of solar active longitudes, where sunspots tend to cluster. In particular, the rotation rate of these regions is poorly known. It is suspected that the active longitude rotation rate (ALRR) is different from the rotation rate of the solar surface. If this is true, the ALRR can be compared with the internal rotation rate deduced by helioseismology providing an estimate of the active region depth. A good determination of the ALRR requires the measurement of the position of thousands of individual active regions, a step best done by interactive examination of images, selection of regions, and determination of heliographic position. These tasks are well-suited for high school students, who are thus provided with a motivation to improve their computer and scientific thinking skills. ScionImage (PC)/NIH Image (Macs) macros for this purpose have been developed which access a CD-ROM of 25 years of NSO/Kitt Peak magnetogram data and laboratory exercises developed previously for classroom use. In the future, a web site will be created for collecting the data from classrooms across the US, and for status reports on the results.

Modified L'Episcopo tendon transfers for irreparable rotator cuff tears: 5-year follow-up.

PubMed

Gerhardt, Christian; Lehmann, Lars; Lichtenberg, Sven; Magosch, Peter; Habermeyer, Peter

2010-06-01

Patients with posterosuperior cuff tears lose functional external rotation of the shoulder. Latissimus dorsi and teres major transfer is performed to restore external rotation. Twenty patients with a mean age was 55.8 +/- 6 years underwent this procedure and were examined at averages of 24.7 (n = 17) and 70.6 (n = 13) months. Two patients did not improve presumably because of failure of the transfer. The Constant and Murley score increased from 55.6 to 90.4 after 2 years and to 87.9 after 5 years. The mean active flexion increased from 119.4 degrees to 169.3 degrees and reached 170 degrees after 5 years, and mean external rotation increased from 12 degrees to 35 degrees , finally reaching 23 degrees . The grade of cuff arthritis progressed from initially Grade 1 in 17% and Grade 2 in 28% to Grade 2 in 8%, Grade 3 in 69%, and Grade 4 in 15% at final followup. The acromiohumeral distance increased from 4.5 mm to 6 mm and decreased to 3.8 mm after 5 years. Electromyographic analysis showed activity during isometric internal and external rotation in the transferred muscle in all patients. The L'Episcopo procedure can restore shoulder function, but cuff arthropathy may progress. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Non-classical continuum theory for solids incorporating internal rotations and rotations of Cosserat theories

NASA Astrophysics Data System (ADS)

Surana, K. S.; Joy, A. D.; Reddy, J. N.

2017-03-01

This paper presents a non-classical continuum theory in Lagrangian description for solids in which the conservation and the balance laws are derived by incorporating both the internal rotations arising from the Jacobian of deformation and the rotations of Cosserat theories at a material point. In particular, in this non-classical continuum theory, we have (i) the usual displacements ( ±b \\varvec{u}) and (ii) three internal rotations ({}_i ±b \\varvec{Θ}) about the axes of a triad whose axes are parallel to the x-frame arising from the Jacobian of deformation (which are completely defined by the skew-symmetric part of the Jacobian of deformation), and (iii) three additional rotations ({}_e ±b \\varvec{Θ}) about the axes of the same triad located at each material point as additional three degrees of freedom referred to as Cosserat rotations. This gives rise to ±b \\varvec{u} and {}_e ±b \\varvec{{Θ} as six degrees of freedom at a material point. The internal rotations ({}_i ±b \\varvec{Θ}), often neglected in classical continuum mechanics, exist in all deforming solid continua as these are due to Jacobian of deformation. When the internal rotations {}_i ±b \\varvec{Θ} are resisted by the deforming matter, conjugate moment tensor arises that together with {}_i ±b \\varvec{Θ} may result in energy storage and/or dissipation, which must be accounted for in the conservation and the balance laws. The Cosserat rotations {}_e ±b \\varvec{Θ} also result in conjugate moment tensor which, together with {}_e ±b \\varvec{Θ}, may also result in energy storage and/or dissipation. The main focus of the paper is a consistent derivation of conservation and balance laws that incorporate aforementioned physics and associated constitutive theories for thermoelastic solids. The mathematical model derived here has closure, and the constitutive theories derived using two alternate approaches are in agreement with each other as well as with the condition resulting from the entropy inequality. Material coefficients introduced in the constitutive theories are clearly defined and discussed.

The influence of applied internal and external rotation on the pivot shift phenomenon.

PubMed

Kopf, Sebastian; Musahl, Volker; Perka, Carsten; Kauert, Ralf; Hoburg, Arnd; Becker, Roland

2017-04-01

The pivot shift test is performed in different techniques and the rotation of the tibia seems to have a significant impact on the amount of the pivot shift phenomenon. It has been hypothesised that external rotation will increase the phenomenon due to less tension at the iliotibial band in knee extension. Twenty-four patients with unilateral anterior cruciate ligament insufficiency were included prospectively. The pivot shift test was performed bilaterally in internal and external tibial rotation under general anaesthesia. Knee motion was captured using a femoral and a tibial inertial sensor. The difference between positive and negative peak values in Euclidean norm of acceleration was calculated to evaluate the amount of the pivot shift phenomenon. The pivot shift phenomenon was significantly increased in patients with ACL insufficiency when the test was performed in external [mean 5.2 ms - 2 (95% CI 4.3-6.0)] compared to internal tibial rotation [mean 4.4 ms - 2 (95% CI 3.5-5.4)] (p = 0.002). In healthy, contralateral knees did not show any difference between external [mean 4.0 ms - 2 (95% CI 3.3-4.7)] and internal tibial rotation [mean 4.0 ms - 2 (95% CI 3.4-4.6)] (ns). The pivot shift phenomenon was increased with external rotation in ACL-insufficient knees, and therefore, one should perform the pivot shift test, rather, in external rotation to easily evoke the, sometimes difficult to detect, pivot shift phenomenon. I (diagnostic study).

The Relationship Between Maximum Isometric Strength and Ball Velocity in the Tennis Serve

PubMed Central

Corbi, Francisco; Fuentes, Juan Pedro; Fernández-Fernández, Jaime

2016-01-01

Abstract The aims of this study were to analyze the relationship between maximum isometric strength levels in different upper and lower limb joints and serve velocity in competitive tennis players as well as to develop a prediction model based on this information. Twelve male competitive tennis players (mean ± SD; age: 17.2 ± 1.0 years; body height: 180.1 ± 6.2 cm; body mass: 71.9 ± 5.6 kg) were tested using maximum isometric strength levels (i.e., wrist, elbow and shoulder flexion and extension; leg and back extension; shoulder external and internal rotation). Serve velocity was measured using a radar gun. Results showed a strong positive relationship between serve velocity and shoulder internal rotation (r = 0.67; p < 0.05). Low to moderate correlations were also found between serve velocity and wrist, elbow and shoulder flexion – extension, leg and back extension and shoulder external rotation (r = 0.36 – 0.53; p = 0.377 – 0.054). Bivariate and multivariate models for predicting serve velocity were developed, with shoulder flexion and internal rotation explaining 55% of the variance in serve velocity (r = 0.74; p < 0.001). The maximum isometric strength level in shoulder internal rotation was strongly related to serve velocity, and a large part of the variability in serve velocity was explained by the maximum isometric strength levels in shoulder internal rotation and shoulder flexion. PMID:28149411

Sensitivity of transitions in internal rotor molecules to a possible variation of the proton-to-electron mass ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, Paul; Ubachs, Wim; Bethlem, Hendrick L.

2011-12-15

Recently, methanol was identified as a sensitive target system to probe variations of the proton-to-electron mass ratio {mu}[Jansen et al., Phys. Rev. Lett. 106, 100801 (2011)]. The high sensitivity of methanol originates from the interplay between overall rotation and hindered internal rotation of the molecule; that is, transitions that convert internal rotation energy into overall rotation energy, or vice versa, have an enhanced sensitivity coefficient, K{sub {mu}}. As internal rotation is a common phenomenon in polyatomic molecules, it is likely that other molecules display similar or even larger effects. In this paper we generalize the concepts that form the foundationmore » of the high sensitivity in methanol and use this to construct an approximate model which makes it possible to estimate the sensitivities of transitions in internal rotor molecules with C{sub 3v} symmetry, without performing a full calculation of energy levels. We find that a reliable estimate of transition sensitivities can be obtained from the three rotational constants (A, B, and C) and three torsional constants (F, V{sub 3}, and {rho}). This model is verified by comparing obtained sensitivities for methanol, acetaldehyde, acetamide, methyl formate, and acetic acid with a full analysis of the molecular Hamiltonian. Of the molecules considered, methanol is by far the most suitable candidate for laboratory and cosmological tests searching for a possible variation of {mu}.« less

The influence of patient factors on femoral rotation after total hip arthroplasty.

PubMed

Tezuka, Taro; Inaba, Yutaka; Kobayashi, Naomi; Choe, Hyonmin; Higashihira, Syota; Saito, Tomoyuki

2018-06-09

A postoperative change in femoral rotation following total hip arthroplasty (THA) might be the cause of dislocation due to the change in combined anteversion. However, very few studies have evaluated the femoral rotation angle following THA, or the factors that influence femoral rotation. We aimed to evaluate changes in femoral rotation after THA, and to investigate preoperative patient factors that influence femoral rotation after THA. This study involved 211 hips treated with primary THA. We used computed tomography to measure the femoral rotation angle before and one week after THA. In addition, multiple regression analysis was performed to evaluate preoperative patient factors that could influence femoral rotation after THA. The femoral rotation angle was 0.2 ± 14° externally before surgery and 4.4 ± 12° internally after surgery (p < 0.001). Multiple regression analysis revealed that sex (β = 0.19; p = 0.003), age (β = 0.15; p = 0.017), preoperative anatomical femoral anteversion (β = - 0.25; p = 0.002), and preoperative femoral rotation angle (β = 0.36; p < 0.001) were significantly associated with the postoperative femoral rotation angle. The final model of the regression formula was described by the following equation: [postoperative femoral rotation angle = 5.41 × sex (female: 0, male: 1) + 0.15 × age - 0.22 × preoperative anatomical femoral anteversion + 0.33 × preoperative femoral rotation angle - 10.1]. The current study showed the mean internal change of 4.6° in the femoral rotation angle one week after THA. Sex, age, preoperative anatomical femoral anteversion and preoperative femoral rotation were associated with postoperative femoral rotation. The patients who were male, older, and who exhibited lesser preoperative anatomical femoral anteversion or greater preoperative femoral rotation angles, tended to demonstrate an externally rotated femur after THA. Conversely, patients who were female, younger, and who exhibited greater preoperative anatomical femoral anteversion or lesser preoperative femoral rotation angles, tended to demonstrate an internal rotation of the femur after THA.

Medialized repair for retracted rotator cuff tears.

PubMed

Kim, Young-Kyu; Jung, Kyu-Hak; Won, Jun-Sung; Cho, Seung-Hyun

2017-08-01

The purpose of this study was to evaluate the functional outcomes of medialized rotator cuff repair and the continuity of repaired tendon in chronic retracted rotator cuff tears. Thirty-five consecutive patients were selected from 153 cases that underwent arthroscopic rotator cuff repair for more than medium-sized posterosuperior rotator cuff tears between July 2009 and July 2012 performed with the medialized repair. All cases were available for at least 2 years of postoperative follow-up. The visual analog scale of pain, muscle strength, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and University of California-Los Angeles score were evaluated. At the final follow-up, all clinical outcomes were significantly improved. The visual analog scale score for pain improved from 6 ± 1 preoperatively to 2 ± 1 postoperatively. The range of motion increased from preoperatively to postoperatively: active forward elevation, from 134° ± 49° to 150° ± 16°; active external rotation at the side, from 47° ± 15° to 55° ± 10°; and active internal rotation, from L3 to L1. The shoulder score also improved: Constant score, from 53.5 ± 16.7 to 79 ± 10; American Shoulder and Elbow Surgeons score, from 51 ± 15 to 82 ± 8; and University of California-Los Angeles score, from 14 ± 4 to 28 ± 4. The retear cases at the final follow-up were 6 (17%). Medialized repair may be useful in cases in which anatomic bone-to-tendon repair would be difficult because of the excessive tension of the repaired tendon and a torn tendon that does not reach the anatomic insertion. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Rotational spectrum of 1,1-difluoroethane-argon: influence of the interaction with the Ar atom on the V 3 barrier to internal rotation of the methyl group

NASA Astrophysics Data System (ADS)

Velino, Biagio; Melandri, Sonia; Favero, Paolo G.; Dell'Erba, Adele; Caminati, Walther

2000-01-01

The free-jet millimeter-wave absorption spectrum of 1,1-difluoroethane-Ar is reported. Most of the measured lines are split due to internal rotation of the methyl group and the tunnelling motion of Ar connecting two equivalent potential energy minima. The Ar atom, close to the CHF 2 group, eclipses one of the methylic hydrogens in the symmetryless geometry of the complex, reducing in this way the barrier to the internal rotation of the methyl group with respect to isolated 1,1-difluoroethane. For high J levels the distance of Ar from the molecule increases, however, due to the centrifugal distortion, and the barrier increases towards the value for 1,1-difluoroethane.

Shoulder Dynamic Control Ratio and Rotation Range of Motion in Female Junior Elite Handball Players and Controls.

PubMed

van Cingel, Robert; Habets, Bas; Willemsen, Linn; Staal, Bart

2018-03-01

To compare glenohumeral range of motion and shoulder rotator muscle strength in healthy female junior elite handball players and controls. Cross-sectional case-control study. Sports medical center. Forty elite female handball players and 30 controls active in nonoverhead sports participated in this study. Passive external rotator (ER), internal rotator (IR), and total range of motion (TROM) of the dominant and nondominant arm were examined with a goniometer. An isokinetic dynamometer was used to evaluate concentric and eccentric rotator muscle strength at 60 and 120 degrees/s with dynamic control ratio (DCR = ERecc:IRcon) as the main outcome parameter. Except for the ER range of motion in the nondominant arm, no significant differences were found between groups for IR, ER of the dominant arm, and the TROM. Within the handball group, the side-to-side difference for IR of the dominant arm was -1.4 degrees. The ER and the TROM of the dominant arm were significantly larger, 6.3 and 4.9 degrees, respectively. For both groups, the DCR values were above 1 and no significant differences were found between the dominant and nondominant arm. The DCR values in the handball group were significantly lower than in the control group. Based on the adopted definitions for muscle imbalance, glenohumeral internal range of motion deficit and TROM deficit our elite female handball players seem not at risk for shoulder injuries. Prospective studies are needed to support the belief that a DCR below 1 places the shoulder at risk for injury.

VLBI astrometry and the Hipparcos link to the extragalactic reference frame

NASA Technical Reports Server (NTRS)

Lestrade, J.-F.; Preston, R. A.; Gabuzda, D. C.; Phillips, R. B.

1991-01-01

Intermediate results are reported from a program of VLBI radio observations designed to establish a link between the rotating reference frame of the ESA Hipparcos astrometric satellite and the extragalactic VLBI frame being developed by the International Earth Rotation Service. A group of 12 link stars have been observed at various epochs since 1982, and more observations are being undertaken during the 3-yr Hipparcos mission (1989-1992). Analysis of data on Algol indicates that phase-reference VLBI can determine an expected sky displacement of 4 marcsec with an uncertainty of 0.5 marcsec, even when the activity is only a few mJy.

Hip kinematics and kinetics in persons with and without cam femoroacetabular impingement during a deep squat task.

PubMed

Bagwell, Jennifer J; Snibbe, Jason; Gerhardt, Michael; Powers, Christopher M

2016-01-01

Previous studies have indicated that hip and pelvis kinematics may be altered during functional tasks in persons with femoroacetabular impingement. The purpose of this study was to compare hip and pelvis kinematics and kinetics during a deep squat task between persons with cam femoroacetabular impingement and pain-free controls. Fifteen persons with cam femoroacetabular impingement and 15 persons without cam femoroacetabular impingement performed a deep squat task. Peak hip flexion, abduction, and internal rotation, and mean hip extensor, adductor, and external rotator moments were quantified. Independent t-tests (α<0.05) were used to evaluate between group differences. Compared to the control group, persons with cam femoroacetabular impingement demonstrated decreased peak hip internal rotation (15.2° (SD 9.5°) vs. 9.4° (SD 7.8°); P=0.041) and decreased mean hip extensor moments (0.56 (SD 0.12) Nm/kg vs. 0.45 (SD 0.15) Nm/kg; P=0.018). In addition persons in the cam femoroacetabular impingement group demonstrated decreased posterior pelvis tilt during squat descent compared to the control group, resulting in a more anteriorly tilted pelvis at the time peak hip flexion (12.5° (SD 17.1°) vs. 23.0° (SD 12.4°); P=0.024). The decreased hip internal rotation observed in persons with cam femoroacetabular impingement may be the result of bony impingement. Furthermore, the decrease in posterior pelvis tilt may contribute to impingement by further approximating the femoral head-neck junction with the acetabulum. Additionally, decreased hip extensor moments suggest that diminished hip extensor muscle activity may contribute to decreased posterior pelvis tilt. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gemelli-obturator complex in the deep gluteal space: an anatomic and dynamic study.

PubMed

Balius, Ramon; Susín, Antonio; Morros, Carles; Pujol, Montse; Pérez-Cuenca, Dolores; Sala-Blanch, Xavier

2018-06-01

To investigate the behavior of the sciatic nerve during hip rotation at subgluteal space. Sonographic examination (high-resolution ultrasound machine at 5.0-14 MHZ) of the gemelli-obturator internus complex following two approaches: (1) a study on cadavers and (2) a study on healthy volunteers. The cadavers were examined in pronation, pelvis-fixed position by forcing internal and external rotations of the hip with the knee in 90° flexion. Healthy volunteers were examined during passive internal and external hip rotation (prone position; lumbar and pelvic regions fixed). Subjects with a history of major trauma, surgery or pathologies affecting the examined regions were excluded. The analysis included eight hemipelvis from six fresh cadavers and 31 healthy volunteers. The anatomical study revealed the presence of connective tissue attaching the sciatic nerve to the structures of the gemellus-obturator system at deep subgluteal space. The amplitude of the nerve curvature during rotating position was significantly greater than during resting position. During passive internal rotation, the sciatic nerve of both cadavers and healthy volunteers transformed from a straight structure to a curved structure tethered at two points as the tendon of the obturator internus contracted downwards. Conversely, external hip rotation caused the nerve to relax. Anatomically, the sciatic nerve is closely related to the gemelli-obturator internus complex. This relationship results in a reproducible dynamic behavior of the sciatic nerve during passive hip rotation, which may contribute to explain the pathological mechanisms of the obturator internal gemellus syndrome.

Effects of Faraday Rotation on Microwave Remote Sensing From Space at L-Band

NASA Technical Reports Server (NTRS)

LeVine, D. M.; Kao, M.

1997-01-01

The effect of Faraday rotation on the remote sensing of soil moisture from space is investigated using the International Reference Ionosphere (IRI) to obtain electron density profiles and the International Geomagnetic Reference Field (IGRF) to model the magnetic field. With a judicious choice of satellite orbit (6 am, sunsynchronous) the errors caused by ignoring Faraday rotation are less than 1 K at incidence angles less than 40 degrees.

Femoroacetabular Impingement in Elite Ice Hockey Goaltenders: Etiological Implications of On-Ice Hip Mechanics.

PubMed

Whiteside, David; Deneweth, Jessica M; Bedi, Asheesh; Zernicke, Ronald F; Goulet, Grant C

2015-07-01

Femoroacetabular impingement (FAI) is particularly prevalent in ice hockey. The butterfly goalie technique is thought to involve extreme ranges of hip motion that may predispose goaltenders to FAI. To quantify hip mechanics during 3 common goaltender movements and interpret their relevance to the development of FAI. Descriptive laboratory study. Fourteen collegiate and professional goaltenders performed skating, butterfly save, and recovery movements on the ice. Hip mechanics were compared across the 3 movements. The butterfly did not exhibit the greatest range of hip motion in any of the 3 planes. Internal rotation was the only hip motion that appeared close to terminal in this study. When subjects decelerated during skating—shaving the blade of their skate across the surface of the ice—the magnitude of peak hip internal rotation was 54% greater than in the butterfly and 265% greater than in the recovery. No movement involved levels of concomitant flexion, adduction, and internal rotation that resembled the traditional impingement (FADIR) test. The magnitude of internal rotation was the most extreme planar hip motion (relative to end-range) recorded in this study (namely during decelerating) and appeared to differentiate this cohort from other athletic populations. Consequently, repetitive end-range hip internal rotation may be the primary precursor to symptomatic FAI in hockey goaltenders and provides the most plausible account for the high incidence of FAI in these athletes. Resection techniques should, therefore, focus on enhancing internal rotation in goaltenders, compared with flexion and adduction. While the butterfly posture can require significant levels of hip motion, recovering from a save and, in particular, decelerating during skating are also demanding on goaltenders' hip joints. Therefore, it appears critical to consider and accommodate a variety of sport-specific hip postures to comprehensively diagnose, treat, and rehabilitate FAI. © 2015 The Author(s).

Biomechanical Effects of Capsular Shift in the Treatment of Hip Microinstability: Creation and Testing of a Novel Hip Instability Model.

PubMed

Jackson, Timothy J; Peterson, Alexander B; Akeda, Masaki; Estess, Allyson; McGarry, Michelle H; Adamson, Gregory J; Lee, Thay Q

2016-03-01

A capsular shift procedure has been described for the treatment of hip instability; however, the biomechanical effects of such a shift are unknown. To create a cadaveric model of hip capsule laxity and evaluate the biomechanical effects of a capsular shift used to treat hip instability on this model. Controlled laboratory study. Eight cadaveric hips with an average age of 58.5 years were tested with a custom hip testing system in 6 conditions: intact, vented, instability, capsulotomy, side-to-side repair, and capsular shift. To create the hip model, the capsule was stretched in extension under 35 N·m of torque for 1 hour in neutral rotation. Measurements included internal and external rotation with 1.5 N·m of torque at 5 positions: 5° of extension and 0°, 15°, 30°, and 45° of flexion for each of the above conditions. The degree of maximum extension with 5 N·m of torque and the amount of femoral distraction with 40 N and 80 N of force were measured. Statistical analysis was performed by use of repeated-measures analysis of variance with Tukey post hoc analysis. The instability state significantly increased internal rotation at all flexion angles and increased distraction compared with the intact state. The capsulotomy condition resulted in significantly increased external rotation and internal rotation at all positions, increased distraction, and maximum extension compared with the intact state. The side-to-side repair condition restored internal rotation back to the instability state but not to the intact state at 5° of extension and 0° of flexion. The capsular shift state significantly decreased internal rotation compared with the instability state at 5° of extension and 0° and 15° of flexion. The capsular shift and side-to-side repair conditions had similar effects on external rotation at all flexion-extension positions. The capsular shift state decreased distraction and maximum extension compared with the instability state, but the side-to-side repair state did not. The hip capsular instability model was shown to have significantly greater total range of motion, external rotation, and extension compared with the intact condition. The greatest effects of capsular shift are seen with internal rotation, maximum extension, and distraction, with minimal effect on external rotation compared with the side-to side repair state. The biomechanical effects of the capsular shift procedure indicate that it can be used to treat hip capsular laxity by decreasing extension and distraction with minimal effect on external rotation. © 2015 The Author(s).

HBT-EP Program: MHD Dynamics and Active Control through 3D Fields and Currents

NASA Astrophysics Data System (ADS)

Navratil, G. A.; Bialek, J.; Brooks, J. W.; Byrne, P. J.; Desanto, S.; Levesque, J. P.; Mauel, M. E.; Stewart, I. G.; Hansen, C. J.

2017-10-01

The HBT-EP active mode control research program aims to: (i) advance understanding of the effects of 3D shaping on advanced tokamak fusion performance, (ii) resolve important MHD issues associated with disruptions, and (iii) measure and mitigate the effects of 3D scrape-off layer (SOL) currents through active and passive control of the plasma edge and conducting boundary structures. Comparison of kink mode structure and RMP response in circular versus diverted plasmas shows good agreement with DCON modeling. SOL current measurements have been used to study SOL current dynamics and current-sharing with the vacuum vessel wall during kink-mode growth and disruptions. A multi-chord extreme UV/soft X-ray array is being installed to provide detailed internal mode structure information. Internal local electrodes were used to apply local bias voltage at two radial locations to study the effect of rotation profile on MHD mode rotation and stability and radial current flow through the SOL. A GPU-based low latency control system using 96 inputs and 64 outputs to apply magnetic perturbations for active control of kink modes is extended to directly control the SOL currents for kink-mode control. An extensive array of SOL current monitors and edge drive electrodes are being installed for pioneering studies of helical edge current control. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Biomechanical comparison of reverse total shoulder arthroplasty systems in soft tissue-constrained shoulders.

PubMed

Henninger, Heath B; King, Frank K; Tashjian, Robert Z; Burks, Robert T

2014-05-01

Numerous studies have examined the biomechanics of isolated variables in reverse total shoulder arthroplasty. This study directly compared the composite performance of two reverse total shoulder arthroplasty systems; each system was designed around either a medialized or a lateralized glenohumeral center of rotation. Seven pairs of shoulders were tested on a biomechanical simulator. Center of rotation, position of the humerus, passive and active range of motion, and force to abduct the arm were quantified. Native arms were tested, implanted with a Tornier Aequalis or DJO Surgical Reverse Shoulder Prosthesis (RSP), and then retested. Differences from the native state were then documented. Both systems shifted the center of rotation medially and inferiorly relative to native. Medial shifts were greater in the Aequalis implant (P < .037). All humeri shifted inferior compared with native but moved medially with the Aequalis (P < .001). Peak passive abduction, internal rotation, and external rotation did not differ between systems (P > .05). Both reverse total shoulder arthroplasty systems exhibited adduction deficits, but the RSP implant deficit was smaller (P = .046 between implants). Both systems reduced forces to abduct the arm compared with native, although the Aequalis required more force to initiate motion from the resting position (P = .022). Given the differences in system designs and configurations, outcome variables were generally comparable. The RSP implant allowed slightly more adduction, had a more lateralized humeral position, and required less force to initiate elevation. These factors may play roles in limiting scapular notching, improving active external rotation by normalizing the residual rotator cuff length, and limiting excessive stress on the deltoid. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Partial rotator cuff repair and biceps tenotomy for the treatment of patients with massive cuff tears and retained overhead elevation: midterm outcomes with a minimum 5 years of follow-up.

PubMed

Cuff, Derek J; Pupello, Derek R; Santoni, Brandon G

2016-11-01

A subset of patients with massive irreparable rotator cuff tears present with retained overhead elevation and pain as their primary complaint. Our aim was to evaluate the outcomes of partial arthroscopic rotator cuff repair with biceps tenotomy and to report the failure rate of this procedure for patients with >5 years of follow-up. Thirty-four patients underwent partial rotator cuff repair and biceps tenotomy for treatment of a massive rotator cuff tear. Patients had preoperative active forward elevation >120° and no radiographic evidence of glenohumeral arthritis. Patients were followed up clinically and radiographically, and 28 patients had a minimum of 5 years of follow-up. Failure was defined as an American Shoulder and Elbow Surgeons score of <70, loss of active elevation >90°, or revision to reverse shoulder arthroplasty during the study period. Patients demonstrated improvements in average preoperative to postoperative American Shoulder and Elbow Surgeons scores (46.6 to 79.3 [P < .001]) and Simple Shoulder Test scores (5.7 to 9.1 [P < .001]) along with decrease in visual analog scale for pain scores (6.9 to 1.9 [P < .001]). No significant change in forward elevation (168° to 154° [P = .07]), external rotation (38° to 39° [P = 1.0]), or internal rotation (84% to 80% [P = 1.0]) was identified; 36% of patients had progression of the Hamada stage. The failure rate was 29%; 75% of patients were satisfied with their index procedure. Partial rotator cuff repair and biceps tenotomy for patients with massive irreparable rotator cuff tears with retained overhead elevation and pain as the primary complaint produced reasonable outcomes at midterm follow-up of at least 5 years. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Surgical correction of shoulder rotation deformity in brachial plexus birth palsy: long-term results in 118 patients.

PubMed

Hultgren, T; Jönsson, K; Roos, F; Järnbert-Pettersson, H; Hammarberg, H

2014-10-01

We present the long-term results of open surgery for internal shoulder rotational deformity in brachial plexus birth palsy (BPBP). From 1997 to 2005, 207 patients (107 females, 100 males, mean age 6.2 (0.6 to 34)) were operated on with subscapularis elongation and/or latissimus dorsi to infraspinatus transfer. Incongruent shoulder joints were relocated. The early results of these patients has been reported previously. We analysed 118 (64 females, 54 males, mean age 15.1 (7.6 to 34)) of the original patient cohort at a mean of 10.4 years (7.0 to 15.1) post-operatively. A third of patients with relocated joints had undergone secondary internal rotational osteotomy of the humerus. A mixed effects models approach was used to evaluate the effects of surgery on shoulder rotation, abduction, and the Mallet score. Independent factors were time (pre-and post-surgery), gender, age, joint category (congruent, relocated, relocated plus osteotomy) and whether or not a transfer had been performed. Data from a previously published short-term evaluation were reworked in order to obtain pre-operative values. The mean improvement in external rotation from pre-surgery to the long-term follow-up was 66.5° (95% confidence interval (CI) 61.5 to 71.6). The internal rotation had decreased by a mean of 22.6° (95% CI -18.7 to -26.5). The mean improvement in the three-grade aggregate Mallet score was 3.1 (95% CI 2.7 to 3.4), from 8.7 (95% CI 8.4 to 9.0) to 11.8 (11.5 to 12.1). Our results show that open subscapularis elongation achieves good long-term results for patients with BPBP and an internal rotation contracture, providing lasting joint congruency and resolution of the trumpet sign, but with a moderate mean loss of internal rotation. ©2014 The British Editorial Society of Bone & Joint Surgery.

The effect of the long head of the biceps on glenohumeral kinematics.

PubMed

Youm, Thomas; ElAttrache, Neal S; Tibone, James E; McGarry, Michelle H; Lee, Thay Q

2009-01-01

The long head of the biceps has been described as a stabilizing force in the setting of glenohumeral instability. However, data are lacking on the effect of loading the long head of the biceps on glenohumeral kinematics. Six cadaveric shoulders were tested for glenohumeral rotational range of motion and translation using a custom shoulder testing system and the Microscribe 3DLX (Immersion, San Jose, CA). The path of glenohumeral articulation (PGA) was measured by calculating the humeral head center with respect to the glenoid articular surface at maximal internal rotation, 30 degrees, 60 degrees, 90 degrees, and maximal external rotation. Significant decreases in glenohumeral rotational range of motion and translation were found with 22-N biceps loading vs the unloaded group. With respect to the PGA, the humeral rotation center was shifted posterior with biceps loading at maximal internal rotation, 30 degrees, and 60 degrees of external rotation. Loading the long head of the biceps significantly affects glenohumeral rotational range of motion, translations, and kinematics.

Relationship between isometric shoulder strength and arms-only swimming power among male collegiate swimmers: study of valid clinical assessment methods.

PubMed

Awatani, Takenori; Morikita, Ikuhiro; Mori, Seigo; Shinohara, Junji; Tatsumi, Yasutaka

2018-04-01

[Purpose] The purpose of the present study was to confirm the relationships between shoulder strength (extensor strength and internal rotator strength) of the abducted position and swimming power during arm-only swimming. [Subjects and Methods] Fourteen healthy male collegiate swimmers participated in the study. Main measures were shoulder strength (strength using torque that was calculated from the upper extremity length and the isometric force of the abducted position) and swimming power. [Results] Internal rotation torque of the dominant side in the abducted external rotated position (r=0.85) was significantly correlated with maximum swimming power. The rate of bilateral difference in extension torque in the maximum abducted position (r=-0.728) was significantly correlated with the swimming velocity-to-swimming power ratio. [Conclusion] The results of this study suggest that internal rotator strength measurement in the abducted external rotated position and extensor strength measurement in the maximum abducted position are valid assessment methods for swimmers.

Strain Response of the Anterior Cruciate Ligament to Uniplanar and Multiplanar Loads During Simulated Landings: Implications for Injury Mechanism.

PubMed

Kiapour, Ata M; Demetropoulos, Constantine K; Kiapour, Ali; Quatman, Carmen E; Wordeman, Samuel C; Goel, Vijay K; Hewett, Timothy E

2016-08-01

Despite basic characterization of the loading factors that strain the anterior cruciate ligament (ACL), the interrelationship(s) and additive nature of these loads that occur during noncontact ACL injuries remain incompletely characterized. In the presence of an impulsive axial compression, simulating vertical ground-reaction force during landing (1) both knee abduction and internal tibial rotation moments would result in increased peak ACL strain, and (2) a combined multiplanar loading condition, including both knee abduction and internal tibial rotation moments, would increase the peak ACL strain to levels greater than those under uniplanar loading modes alone. Controlled laboratory study. A cadaveric model of landing was used to simulate dynamic landings during a jump in 17 cadaveric lower extremities (age, 45 ± 7 years; 9 female and 8 male). Peak ACL strain was measured in situ and characterized under impulsive axial compression and simulated muscle forces (baseline) followed by addition of anterior tibial shear, knee abduction, and internal tibial rotation loads in both uni- and multiplanar modes, simulating a broad range of landing conditions. The associations between knee rotational kinematics and peak ACL strain levels were further investigated to determine the potential noncontact injury mechanism. Externally applied loads, under both uni- and multiplanar conditions, resulted in consistent increases in peak ACL strain compared with the baseline during simulated landings (by up to 3.5-fold; P ≤ .032). Combined multiplanar loading resulted in the greatest increases in peak ACL strain (P < .001). Degrees of knee abduction rotation (R(2) = 0.45; β = 0.42) and internal tibial rotation (R(2) = 0.32; β = 0.23) were both significantly correlated with peak ACL strain (P < .001). However, changes in knee abduction rotation had a significantly greater effect size on peak ACL strain levels than did internal tibial rotation (by ~2-fold; P < .001). In the presence of impulsive axial compression, the combination of anterior tibial shear force, knee abduction, and internal tibial rotation moments significantly increases ACL strain, which could result in ACL failure. These findings support multiplanar knee valgus collapse as one the primary mechanisms of noncontact ACL injuries during landing. Intervention programs that address multiple planes of loading may decrease the risk of ACL injury and the devastating consequences of posttraumatic knee osteoarthritis. © 2016 The Author(s).

Can activity within the external abdominal oblique be measured using real-time ultrasound imaging?

PubMed

John, E K; Beith, I D

2007-11-01

Differences in the function of the anterolateral abdominal muscles have been the subject of much investigation, but primarily using electromyography. Recently changes in thickness of transversus abdominis and internal oblique measured from real-time ultrasound images have been shown to represent activity within these muscles. However it is still unclear if such a change in thickness in external oblique similarly represents activity within that muscle. The purpose of this study was to investigate the relationship between change in thickness and muscle activity in the external oblique using real-time ultrasound and surface electromyography. Simultaneous measurements of electromyography and real-time ultrasound images of external oblique were studied in up to 24 subjects during two tasks compared to the muscle at rest (1) isometric trunk rotation and (2) drawing in the lower abdomen. Changes in muscle thickness correlated significantly with electromyography during isometric trunk rotation in the majority of subjects but with a significant difference between subjects. In contrast, the relationship between change in thickness and electrical activity in the muscle when drawing in the lower abdomen was significant in less than 50% of subjects and the muscle often got thinner. Thickness changes of external oblique can be used as a valid indicator of electromyography activity during isometric trunk rotation, though the relationship is not as good as previously published data for transversus abdominis. Thickness changes of external oblique measured during lower abdominal drawing in cannot be used to detect activity within this muscle.

Development of a cryogenic rotating heat pipe joint

NASA Technical Reports Server (NTRS)

1978-01-01

The performance of two critical technology components required for a continuously rotatable heat pipe: (1) a low-leakage rotatable coupling for the heat pipe pressure vessel, and (2) a rotatable internal wick, is reported. Performance and leakage requirements were established based on 12 months operation of a cryogenic rotatable heat pipe on a satellite in earth orbit.

The Acute Effects of Hold-Relax Proprioceptive Neuromuscular Facilitation With Vibration Therapy on Glenohumeral Internal-Rotation Deficit.

PubMed

Tucker, W Steven; Slone, Stephen W

2016-08-01

Clinicians use various stretching techniques to prevent the onset of and treat glenohumeral internal-rotation deficit (GIRD). It is unknown which stretching technique is the most effective. To investigate the acute effects of hold-relax proprioceptive neuromuscular facilitation (PNF) with and without vibration therapy on internal rotation in individuals with GIRD. 2-within (stretch × time) comparison with repeated measures. Controlled laboratory. 11 male current and former overhead athletes (19.8 ± 1.4 y, 184.5 ± 4.5 cm, 91.8 ± 11.6 kg) who presented with GIRD. At 3 separate sessions, participants performed 1 of 3 randomly assigned stretches: hold-relax PNF (PNF), hold-relax PNF in combination with a whole-body-vibration unit set at 30 Hz (PNF-V), and static stretch (SS). Pretest and posttest maximum passive glenohumeral internal-rotation measurements were taken with a digital protractor. The dependent variables were the mean glenohumeral internal-rotation measurements taken at the pretest and posttest. The influence of stretch (PNF, PNF-V, and SS) and time (pretest and posttest) on mean glenohumeral internal rotation was compared using a 3 × 2 factorial ANOVA with repeated measures on both variables (P ≤ .05). There was a stretch-by-time interaction (F2,20 = 34.697, P < .001). Post hoc testing revealed that the PNF posttest (73.0° ± 10.4°) was greater than the PNF pretest (60.0° ± 11.8°), the PNF-V posttest (74.7° ± 10.0°) was greater than the PNF-V pretest (57.4° ± 10.4°), and the SS posttest (67.0° ± 10.7°) was greater than the SS pretest (60.1° ± 9.4°). When comparing the posttest values, the PNF-V posttest was greater than the SS posttest. All 3 stretches (PNF, PNF-V, and SS) resulted in acute increases in glenohumeral internal rotation in individuals presenting with GIRD. The PNF-V stretch resulted in the greatest increase and would be the most clinically beneficial for patients with GIRD.

Global rotation of mechanical metamaterials induced by their internal deformation

NASA Astrophysics Data System (ADS)

Dudek, K. K.; Gatt, R.; Mizzi, L.; Dudek, M. R.; Attard, D.; Grima, J. N.

2017-09-01

In this work, we propose the concept that a device based on mechanical metamaterials can be used to induce and control its own rotational motion as a result of internal deformations due to the conversion of translational degrees of freedom into rotational ones. The application of a linear force on the structural units of the system may be fine-tuned in order to obtain a desired type of rotation. In particular, we show, how it is possible to maximise the extent of rotation of the system through the alteration of the geometry of the system. We also show how a device based on this concept can be connected to an external body in order to rotate it which result may potentially prove to be very important in the case of applications such as telescopes employed in space.

The Microwave Spectroscopy Study of 1,2-DIMETHOXYETHANE

NASA Astrophysics Data System (ADS)

Li, Weixing; Vigorito, Annalisa; Calabrese, Camilla; Evangelisti, Luca; Favero, Laura B.; Maris, Assimo; Melandri, Sonia

2017-06-01

With Pulsed-Jet Fourier Transform MicroWave (PJ-FTMW) spectroscopy and Stark modulated Free Jet Millimeter-Wave absorption (FJ-AMMW) spectroscopy, the rotational spectra of two conformers of 1,2-Dimethoxyethane were identified and characterized. Besides the normal species, the spectra of all the mono-substituted ^{13}C isotopologues in natural abundance were also measured. By fitting the rotational transitions split by the methyl internal rotations using both XIAM and ERHAM programs, the spectroscopic parameters were obtained and compared. The rotational constants indicated the conformers to be TGT and TGG', respectively. With the rotational constants of the normal and ^{13}C species, the coordinates of the substituted carbon atoms could be calculated with Kraitchmann's equations. The carbon-frameworks further confirmed the assignment of the two conformations. The V_{3} barriers of the two methyl groups' internal rotations were also experimentally determined.

Short-Term Effects of Thoracic Spine Manipulation on Shoulder Impingement Syndrome: A Randomized Controlled Trial.

PubMed

Haik, Melina N; Alburquerque-Sendín, Francisco; Camargo, Paula R

2017-08-01

To investigate the short-term effects of thoracic spine manipulation (TSM) on pain, function, scapular kinematics, and scapular muscle activity in individuals with shoulder impingement syndrome. Randomized controlled trial with blinded assessor and patient. Laboratory. Patients with shoulder impingement syndrome (N=61). Participants were randomly allocated to TSM group (n=30) or sham-TSM group (n=31) and attended 2 intervention sessions over a 1-week period. Scapular kinematics and muscle activity were measured at day 1 (baseline, before the first intervention), day 2 preintervention (before second intervention), day 2 postintervention (after the second intervention), and day 3 (follow-up). Shoulder pain and function were assessed by the Disability of the Arm, Shoulder and Hand questionnaire and Western Ontario Rotator Cuff Index at baseline, day 2 preintervention, and follow-up. An assessor blinded to group assignment measured all outcomes. Pain decreased by 0.7 points (95% confidence interval, 1.3-0.1 points) at day 2 preintervention and 0.9 points (95% confidence interval, 1.5-0.3 points) at day 2 postintervention in the TSM group. The Disability of the Arm, Shoulder and Hand questionnaire (P=.01) and Western Ontario Rotator Cuff Index (P=.02) scores improved in both groups. Scapular upward rotation increased during arm lowering (P<.01) at day 2 postintervention (5.3°) and follow-up (3.5°) in the TSM group. Upper trapezius activity increased (P<.05) in the sham-TSM group. Middle trapezius, lower trapezius, and serratus anterior decreased activities in both groups during elevation and lowering of the arm. TSM may increase scapular upward rotation during arm lowering. TSM does not seem to influence activity of the scapular muscles. The results concerning shoulder pain, function, scapular tilt, and internal rotation are not conclusive. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Static internal performance of a two-dimensional convergent nozzle with thrust-vectoring capability up to 60 deg

NASA Technical Reports Server (NTRS)

Leavitt, L. D.

1985-01-01

An investigation was conducted at wind-off conditions in the static-test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance characteristics of a two-dimensional convergent nozzle with a thrust-vectoring capability up to 60 deg. Vectoring was accomplished by a downward rotation of a hinged upper convergent flap and a corresponding rotation of a center-pivoted lower convergent flap. The effects of geometric thrust-vector angle and upper-rotating-flap geometry on internal nozzle performance characteristics were investigated. Nozzle pressure ratio was varied from 1.0 (jet off) to approximately 5.0.

The internal dynamics of slowly rotating biological systems

NASA Technical Reports Server (NTRS)

Kessler, John O.

1992-01-01

The structure and the dynamics of biological systems are complex. Steady gravitational forces that act on organisms cause hydrostatic pressure gradients, stress in solid components, and ordering of movable subsystems according to density. Rotation induces internal motion; it also stresses and or deforms regions of attachment and containment. The disrupted gravitationally ordered layers of movable entities are replaced by their orbital movements. New ordering geometries may arise also, especially if fluids of various densities occur. One novel result obtained concerns the application of scheduled variation of clinostat rotation rates to the management of intracellular particle trajectories. Rotation and its consequences are discussed in terms of scaling factors for parameters such as time, derived from mathematical models for simple rotating mechanical systems.

The effect of long and short head biceps loading on glenohumeral joint rotational range of motion and humeral head position.

PubMed

McGarry, Michelle H; Nguyen, Michael L; Quigley, Ryan J; Hanypsiak, Bryan; Gupta, Ranjan; Lee, Thay Q

2016-06-01

To evaluate the effect of loading the long and short heads of the biceps on glenohumeral range of motion and humeral head position. Eight cadaveric shoulders were tested in 60° abduction in the scapula and coronal plane. Muscle loading was applied based on cross-sectional area ratios. The short and long head of the biceps were loaded individually followed by combined loading. Range of motion was measured with 2.2 Nm torque, and the humeral head apex position was measured using a MicroScribe. A paired t test with Bonferroni correction was used for statistics. Long head loading decreased internal rotation in both the scapular (17.9 %) and coronal planes (5.7 %) and external rotation in the scapular plane (2.6 %) (P < 0.04). With only short head loading, maximum internal rotation was significantly increased in the scapular and coronal plane. Long head and short head loading shifted the humeral head apex posteriorly in maximum internal rotation in both planes with the long head shift being significantly greater than the short head. Long head loading also shifted the humeral apex inferiorly in internal rotation and inferiorly posteriorly in neutral rotation in the scapular plane. With the long head unloaded, there was a significant superior shift with short head loading in both planes. Loading the long head of the biceps had a much greater effect on glenohumeral range of motion and humeral head shift than the short head of the biceps; however, in the absence of long head loading, with the short head loaded, maximum internal rotation increases and the humeral head shifts superiorly, which may contribute to impingement following tenodesis of the long head of the biceps. These small changes in rotational range of motion and humeral head position with biceps tenodesis may not lead to pathologic conditions in low-demand patients; however, in throwers, biceps tenodesis may lead to increased contact pressures in late-cocking and deceleration that will likely translate to decreased performance therefore every effort should be made to preserve the biceps-labral complex.

Non-classical continuum theory for fluids incorporating internal and Cosserat rotation rates

NASA Astrophysics Data System (ADS)

Surana, K. S.; Joy, A. D.; Reddy, J. N.

2017-11-01

This paper presents a non-classical continuum theory for fluent continua in which the conservation and balance laws are derived by incorporating both internal rotation rates arising from the velocity gradient tensor and the rotation rates of the Cosserats. Specifically, in this non-classical continuum theory we have (1) the usual velocities (\\bar{ ±b {\\varvec{v }}}), (2) the three internal rotation rates ({}_i^t\\bar{ ±b {\\varvec{Θ }}}) about the axes of a fixed triad whose axes are parallel to the x-frame arising from the velocity gradient tensor (\\bar{ ±b {\\varvec{L }}}) that are completely defined by the antisymmetric part of the velocity gradient tensor, and (3) three additional rotation rates ({}_e^t\\bar{ ±b {\\varvec{Θ }}}) about the axes of the same triad located at each material point as additional three unknown degrees of freedom, referred to as Cosserat rotation rates. This gives rise to \\bar{ ±b {\\varvec{v }}} and {}_e^t\\bar{ ±b {\\varvec{Θ }}} as six degrees of freedom at a material point. The internal rotation rates {}_i^t\\bar{ ±b {\\varvec{Θ }}}, often neglected in classical fluid mechanics, exist in all deforming fluent continua as these are due to velocity gradient tensor. When the internal rotation rates {}_i^t\\bar{ ±b {\\varvec{Θ }}} are resisted by deforming fluent continua, conjugate moment tensor arises that together with {}_i^t\\bar{ ±b {\\varvec{Θ }}} may result in energy storage and/or dissipation, which must be considered in the conservation and balance laws. The Cosserat rotation rations {}_e^t\\bar{ ±b {\\varvec{Θ }}} also result in conjugate moment tensor that together with {}_e^t\\bar{ ±b {\\varvec{Θ }}} may also result in energy storage and/or dissipation. The main focus of this paper is a consistent derivation of conservation and balance laws for fluent continua that incorporate the aforementioned physics and associated constitutive theories for thermofluids using the conditions resulting from the entropy inequality. The material coefficients derived in the constitutive theories are clearly defined and discussed.

Forefoot-rearfoot coupling patterns and tibial internal rotation during stance phase of barefoot versus shod running.

PubMed

Eslami, Mansour; Begon, Mickaël; Farahpour, Nader; Allard, Paul

2007-01-01

Based on twisted plate and mitered hinge models of the foot and ankle, forefoot-rearfoot coupling motion patterns can contribute to the amount of tibial rotation. The present study determined the differences of forefoot-rearfoot coupling patterns as well as excessive excursion of tibial internal rotation in shod versus barefoot conditions during running. Sixteen male subjects ran 10 times at 170 steps per minute under the barefoot and shod conditions. Forefoot-rearfoot coupling motions were assessed by measuring mean relative phase angle during five intervals of stance phase for the main effect of five time intervals and two conditions (ANOVA, P<0.05). Tibial internal rotation excursion was compared between the shod and barefoot conditions over the first 50% of stance phase using paired t-test, (P<0.05). Forefoot adduction/abduction and rearfoot eversion/inversion coupling motion patterns were significantly different between the conditions and among the intervals (P<0.05; effect size=0.47). The mean absolute relative angle was significantly modified to 37 degrees in-phase relationship at the heel-strike of running with shoe wears. No significant differences were noted in the tibial internal rotation excursion between shod and barefoot conditions. Significant variations in the forefoot adduction/abduction and rearfoot eversion/inversion coupling patterns could have little effect on the amount of tibial internal rotation excursion. Yet it remains to be determined whether changes in the frontal plane forefoot-rearfoot coupling patterns influence the tibia kinematics for different shoe wears or foot orthotic interventions. The findings question the rational for the prophylactic use of forefoot posting in foot orthoses.

Outcomes of hip resurfacing in a professional dancer: a case report.

PubMed

Dunleavy, Kim

2012-02-01

A new surgical option (hip resurfacing arthroplasty) is now available for younger patients with hip osteoarthritis. A more aggressive rehabilitation program than the typical total hip arthroplasty protocol is needed for active individuals. This case report describes interventions used to maximize function in a 46-year-old professional dancer after hip resurfacing with a progressive therapeutic exercise program. Exercise choices were selected to address dance-specific requirements while respecting healing of the posterior capsular incision. Strengthening focused on hip abduction, extension, and external rotation. Precautions included avoiding gluteal stretching until 6 months. Pelvic alignment and weight-bearing distribution were emphasized. The patient was able to return to rehearsal by 7 months, at which time strength was equivalent to the unaffected leg. Range of motion reached unaffected side values at week 8 for internal rotation, week 11 for extension, week 13 for adduction, and week 28 for flexion. External rotation and abduction were still limited at 1 year, which influenced pelvic alignment with resultant pain on the unaffected side. Functional and impairment outcomes are presented with timelines to provide a basis for postoperative benchmarks for active clients after hip resurfacing. Although this case report presents a dance-specific program, exercise progressions for other active individuals may benefit from similar exercise intensity and sports-specific focus. Future rehabilitation programs should take into account possible flexion and external rotation range limitations and the need for gluteal muscle strengthening along with symmetry and pelvic alignment correction. Long-term studies investigating intensity of rehabilitation are warranted for patients intending to participate in higher level athletic activity.

An In Vitro Robotic Assessment of the Anterolateral Ligament, Part 1: Secondary Role of the Anterolateral Ligament in the Setting of an Anterior Cruciate Ligament Injury.

PubMed

Rasmussen, Matthew T; Nitri, Marco; Williams, Brady T; Moulton, Samuel G; Cruz, Raphael Serra; Dornan, Grant J; Goldsmith, Mary T; LaPrade, Robert F

2016-03-01

Recent investigations have described the structural and functional behavior of the anterolateral ligament (ALL) of the knee through pull-apart and isolated sectioning studies. However, the secondary stabilizing role of the ALL in the setting of a complete anterior cruciate ligament (ACL) tear has not been fully defined for common simulated clinical examinations, such as the pivot-shift, anterior drawer, and internal rotation tests. Combined sectioning of the ALL and ACL would lead to increased internal rotation and increased axial plane translation during a pivot-shift test when compared with isolated sectioning of the ACL. Controlled laboratory study. Ten fresh-frozen human cadaveric knees were subjected to a simulated pivot-shift test with coupled 10-N·m valgus and 5-N·m internal rotation torques from 0° to 60° of knee flexion and a 5-N·m internal rotation torque and an 88-N anterior tibial load, both from 0° to 120° of knee flexion via a 6 degrees of freedom robotic system. Kinematic changes were measured and compared with the intact state for isolated sectioning of the ACL and combined sectioning of the ACL and ALL. Combined sectioning of the ACL and ALL resulted in a significant increase in axial plane tibial translation during a simulated pivot shift at 0°, 15°, 30°, and 60° of knee flexion and a significant increase in internal rotation at 0°, 15°, 30°, 45°, 60°, 75°, 90°, 105°, and 120° when compared with the intact and ACL-deficient states. Based on the model results, ALL sectioning resulted in an additional 2.1 mm (95% CI, 1.4-2.9 mm; P < .001) of axial plane translation during the pivot shift when compared with ACL-only sectioning, when pooling evidence over all flexion angles. Likewise, when subjected to IR torque, the ACL+ALL-deficient state resulted in an additional 3.2° of internal rotation (95% CI, 2.4°-4.1°; P < .001) versus the intact state, and the additional sectioning of the ALL increased internal rotation by 2.7° (95% CI, 1.8°-3.6°; P < .001) versus the ACL-deficient state. The results of this study confirm the ALL as an important lateral knee structure that provides rotatory stability to the knee. Specifically, the ALL was a significant secondary stabilizer throughout flexion during an applied internal rotation torque and simulated pivot-shift test in the context of an ACL-deficient knee. Residual internal rotation and a positive pivot shift after ACL reconstruction may be attributed to ALL injury. For these patients, surgical treatment of an ALL tear may be considered. © 2015 The Author(s).

Stability analysis of internally damped rotating composite shafts using a finite element formulation

NASA Astrophysics Data System (ADS)

Ben Arab, Safa; Rodrigues, José Dias; Bouaziz, Slim; Haddar, Mohamed

2018-04-01

This paper deals with the stability analysis of internally damped rotating composite shafts. An Euler-Bernoulli shaft finite element formulation based on Equivalent Single Layer Theory (ESLT), including the hysteretic internal damping of composite material and transverse shear effects, is introduced and then used to evaluate the influence of various parameters: stacking sequences, fiber orientations and bearing properties on natural frequencies, critical speeds, and instability thresholds. The obtained results are compared with those available in the literature using different theories. The agreement in the obtained results show that the developed Euler-Bernoulli finite element based on ESLT including hysteretic internal damping and shear transverse effects can be effectively used for the stability analysis of internally damped rotating composite shafts. Furthermore, the results revealed that rotor stability is sensitive to the laminate parameters and to the properties of the bearings.

Subscapularis slide correction of the shoulder internal rotation contracture after brachial plexus birth injury: technique and outcomes.

PubMed

Immerman, Igor; Valencia, Herbert; DiTaranto, Patricia; DelSole, Edward M; Glait, Sergio; Price, Andrew E; Grossman, John A I

2013-03-01

Internal rotation contracture is the most common shoulder deformity in patients with brachial plexus birth injury. The purpose of this investigation is to describe the indications, technique, and results of the subscapularis slide procedure. The technique involves the release of the subscapularis muscle origin off the scapula, with preservation of anterior shoulder structures. A standard postoperative protocol is used in all patients and includes a modified shoulder spica with the shoulder held in 60 degrees of external rotation and 30 degrees of abduction, aggressive occupational and physical therapy, and subsequent shoulder manipulation under anesthesia with botulinum toxin injections as needed. Seventy-one patients at 2 institutions treated with subscapularis slide between 1997 and 2010, with minimum follow-up of 39.2 months, were identified. Patients were divided into 5 groups based on the index procedure performed: subscapularis slide alone (group 1); subscapularis slide with a simultaneous microsurgical reconstruction (group 2); primary microsurgical brachial plexus reconstruction followed later by a subscapularis slide (group 3); primary microsurgical brachial plexus reconstruction followed later by a subscapularis slide combined with tendon transfers for shoulder external rotation (group 4); and subscapularis slide with simultaneous tendon transfers, with no prior brachial plexus surgery (group 5). Full passive external rotation equivalent to the contralateral side was achieved in the operating room in all cases. No cases resulted in anterior instability or internal rotation deficit. Internal rotation contracture of the shoulder after brachial plexus birth injury can be effectively managed with the technique of subscapularis slide.

Profile of isokinetic eccentric-to-concentric strength ratios of shoulder rotator muscles in elite female team handball players.

PubMed

Andrade, Marilia Dos Santos; Fleury, Anna Maria; de Lira, Claudio Andre Barbosia; Dubas, Joao Paulo; da Silva, Antonio Carlos

2010-05-01

The purpose of this study was to establish the isokinetic profile of shoulder rotator muscles strength in female handball players. Twenty-seven handball players performed concentric and eccentric strength tests of both dominant and non-dominant upper limbs on an isokinetic dynamometer. Internal and external rotator muscles peak torque was assessed at 1.05, 3.14, and 5.23 rad . s(-1) in concentric mode and at 3.14 and 5.23 rad . s(-1) in eccentric mode. Concentric balance ratio and functional ratio were obtained. Bi-lateral deficiency was compared. Concentric strength for internal and external rotation was significantly greater for the dominant than for the non-dominant limb for all speeds (P < or = 0.0001). For eccentric actions, internal rotator muscles were stronger in the dominant than the non-dominant limb (P < or = 0.0001) at both speeds. Concentric balance and functional balance ratios did not differ between sides at 3.14 rad . s(-1) (P = 0.1631), but at 5.23 rad . s(-1) the functional balance ratio in the dominant limb was lower than for the non-dominant limb (P = 0.0500). Although the dominant side was stronger than the non-dominant side, balance concentric ratios remained the same, with only the functional strength ratio different at 5.23 rad . s(-1). Our results suggest that concentric strength exercises be used for internal and external rotators on the non-dominant side, and functional exercise that improves eccentric rotation strength for prevention programmes.

Editorial Commentary: The Downstream Effects of Limited Hip Rotation and Femoroacetabular Impingement on the Anterior Cruciate Ligament: Could a Little Hip Stretching Every Day (or Surgery) Keep the Knee Doctor Away?

PubMed

Boykin, Robert E

2018-03-01

Patients with radiographic evidence of femoroacetabular impingement and decreased hip internal rotation have a higher rate of anterior cruciate ligament (ACL) tears. Limited internal rotation of the hip increases strain and potentially resultant fatigue failure of the ACL. Although causation has not been proven, a better understanding of the lower extremity kinetic chain may allow improved ACL prevention strategies through measures (operative or nonoperative) to improve rotation of the hip. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Light-pulse atom interferometric device

DOEpatents

Biedermann, Grant; McGuinness, Hayden James Evans; Rakholia, Akash; Jau, Yuan-Yu; Schwindt, Peter; Wheeler, David R.

2016-03-22

An atomic interferometric device useful, e.g., for measuring acceleration or rotation is provided. The device comprises at least one vapor cell containing a Raman-active chemical species, an optical system, and at least one detector. The optical system is conformed to implement a Raman pulse interferometer in which Raman transitions are stimulated in a warm vapor of the Raman-active chemical species. The detector is conformed to detect changes in the populations of different internal states of atoms that have been irradiated by the optical system.

In situ forces and length patterns of the fibular collateral ligament under controlled loading: an in vitro biomechanical study using a robotic system.

PubMed

Liu, Ping; Wang, Jianquan; Xu, Yan; Ao, Yingfang

2015-04-01

The aim of this study was to determine the in situ forces and length patterns of the fibular collateral ligament (FCL) and kinematics of the knee under various loading conditions. Six fresh-frozen cadaveric knees were used (mean age 46 ± 14.4 years; range 20-58). In situ forces and length patterns of FCL and kinematics of the knee were determined under the following loading conditions using a robotic/universal force-moment sensor testing system: no rotation, varus (10 Nm), external rotation (5 Nm), and internal rotation (5 Nm) at 0°, 15°, 30°, 60º, 90°, and 120° of flexion, respectively. Under no rotation loading, the distances between the centres of the FCL attachments decreased as the knee flexed. Under varus loading, the force in FCL peaked at 15° of flexion and decreased with further knee flexion, while distances remained nearly constant and the varus rotation increased with knee flexion. Using external rotation, the force in the FCL also peaked at 15° flexion and decreased with further knee flexion, the distances decreased with flexion, and external rotation increased with knee flexion. Using internal rotation load, the force in the FCL was relatively small across all knee flexion angles, and the distances decreased with flexion; the amount of internal rotation was fairly constant. FCL has a primary role in preventing varus and external rotation at 15° of flexion. The FCL does not perform isometrically following knee flexion during neutral rotation, and tibia rotation has significant effects on the kinematics of the FCL. Varus and external rotation laxity increased following knee flexion. By providing more realistic data about the function and length patterns of the FCL and the kinematics of the intact knee, improved reconstruction and rehabilitation protocols can be developed.

Parsec-scale Faraday rotation and polarization of 20 active galactic nuclei jets

NASA Astrophysics Data System (ADS)

Kravchenko, E. V.; Kovalev, Y. Y.; Sokolovsky, K. V.

2017-05-01

We perform polarimetry analysis of 20 active galactic nuclei jets using the very long baseline array at 1.4, 1.6, 2.2, 2.4, 4.6, 5.0, 8.1, 8.4 and 15.4 GHz. The study allowed us to investigate linearly polarized properties of the jets at parsec scales: distribution of the Faraday rotation measure (RM) and fractional polarization along the jets, Faraday effects and structure of Faraday-corrected polarization images. Wavelength dependence of the fractional polarization and polarization angle is consistent with external Faraday rotation, while some sources show internal rotation. The RM changes along the jets, systematically increasing its value towards synchrotron self-absorbed cores at shorter wavelengths. The highest core RM reaches 16 900 rad m-2 in the source rest frame for the quasar 0952+179, suggesting the presence of highly magnetized, dense media in these regions. The typical RM of transparent jet regions has values of an order of a hundred rad m-2. Significant transverse RM gradients are observed in seven sources. The magnetic field in the Faraday screen has no preferred orientation, and is observed to be random or regular from source to source. Half of the sources show evidence for the helical magnetic fields in their rotating magneto-ionic media. At the same time jets themselves contain large-scale, ordered magnetic fields and tend to align its direction with the jet flow. The observed variety of polarized signatures can be explained by a model of spine-sheath jet structure.

Titan's rotation reveals an internal ocean and changing zonal winds

USGS Publications Warehouse

Lorenz, R.D.; Stiles, B.W.; Kirk, R.L.; Allison, M.D.; Del Marmo, P.P.; Iess, L.; Lunine, J.I.; Ostro, S.J.; Hensley, S.

2008-01-01

Cassini radar observations of Saturn's moon Titan over several years show that its rotational period is changing and is different from its orbital period. The present-day rotation period difference from synchronous spin leads to a shift of ???0.36?? per year in apparent longitude and is consistent with seasonal exchange of angular momentum between the surface and Titan's dense superrotating atmosphere, but only if Titan's crust is decoupled from the core by an internal water ocean like that on Europa.

In vivo kinematics of healthy male knees during squat and golf swing using image-matching techniques.

PubMed

Murakami, Koji; Hamai, Satoshi; Okazaki, Ken; Ikebe, Satoru; Shimoto, Takeshi; Hara, Daisuke; Mizu-uchi, Hideki; Higaki, Hidehiko; Iwamoto, Yukihide

2016-03-01

Participation in specific activities requires complex ranges of knee movements and activity-dependent kinematics. The purpose of this study was to investigate dynamic knee kinematics during squat and golf swing using image-matching techniques. Five healthy males performed squats and golf swings under periodic X-ray images at 10 frames per second. We analyzed the in vivo three-dimensional kinematic parameters of subjects' knees, namely the tibiofemoral flexion angle, anteroposterior (AP) translation, and internal-external rotation, using serial X-ray images and computed tomography-derived, digitally reconstructed radiographs. During squat from 0° to 140° of flexion, the femur moved about 25 mm posteriorly and rotated 19° externally relative to the tibia. Screw-home movement near extension, bicondylar rollback between 20° and 120° of flexion, and medial pivot motion at further flexion were observed. During golf swing, the leading and trailing knees (the left and right knees respectively in the right-handed golfer) showed approximately five millimeters and four millimeters of AP translation with 18° and 26° of axial rotation, respectively. A central pivot motion from set-up to top of the backswing, lateral pivot motion from top to ball impact, and medial pivot motion from impact to the end of follow-through were observed. The medial pivot motion was not always recognized during both activities, but a large range of axial rotation with bilateral condylar AP translations occurs during golf swing. This finding has important implications regarding the amount of acceptable AP translation and axial rotation at low flexion in replaced knees. IV. Copyright © 2015 Elsevier B.V. All rights reserved.

Rotational Spectrum and Internal Rotation Barrier of 1-Chloro-1,1-difluoroethane

NASA Astrophysics Data System (ADS)

Alonso, José L.; López, Juan C.; Blanco, Susana; Guarnieri, Antonio

1997-03-01

The rotational spectra of 1-chloro-1,1-difluoroethane (HCFC-142b) has been investigated in the frequency region 8-115 GHz with Stark, waveguide Fourier transform (FTMW), and millimeter-wave spectrometers. Assignments in large frequency regions with the corresponding frequency measurements have been made for the ground andv18= 1 (CH3torsion) vibrational states of the35Cl isotopomer and for the ground state of the37Cl species. Accurate rotational, quartic centrifugal distortion, and quadrupole coupling constants have been determined from global fits considering all these states. SmallA-Einternal rotation splittings have been observed for thev18= 1 vibrational state using FTMW spectroscopy. The barrier height for the internal rotation of the methyl group has been determined to be 3751 (4) cal mol-1, in disagreement with the previous microwave value of 4400 (100) cal mol-1reported by G. Graner and C. Thomas [J. Chem. Phys.49,4160-4167 (1968)].

Effect of toroidal field ripple on the formation of internal transport barriers

NASA Astrophysics Data System (ADS)

de Vries, P. C.; Joffrin, E.; Hawkes, N. C.; Litaudon, X.; Challis, C. D.; Andrew, Y.; Beurskens, M.; Brix, M.; Brzozowski, J.; Crombé, K.; Giroud, C.; Hobirk, J.; Johnson, T.; Lönnroth, J.; Salmi, A.; Tala, T.; Yavorskij, V.; Zastrow, K.-D.; EFDA Contributors, JET

2008-06-01

The effect of a toroidal field (TF) ripple on the formation and performance of internal transport barriers (ITBs) has been studied in JET. It was found that the TF ripple had a profound effect on the toroidal plasma rotation. An increased TF ripple up to δ = 1% led to a lower rotation and reduced the rotational shear in the region where the ITBs were formed. ITB triggering events were observed in all cases and it is thought that the rotational shear may be less important for this process than, for example, the q-profile. However, the increase in the pressure gradient following the ITB trigger was reduced in discharges with a larger TF ripple and consequently a lower rotational shear. This suggests that toroidal rotation and its shear play a role in the growth of the ITB once it has been triggered.

Intrinsic rotation, hysteresis and back transition in reversed shear internal transport barriers

NASA Astrophysics Data System (ADS)

Kim, S. S.; Jhang, Hogun; Diamond, P. H.; Terzolo, L.; Yi, S.; Hahm, T. S.

2011-07-01

A study of intrinsic rotation and hysteresis in ion thermal internal transport barrier (ITB) is presented. Global flux-driven gyrofluid simulations are performed. It is found that significant co-current intrinsic rotation (0.1 <~ Mth <~ 0.2, where Mth is the thermal Mach number) can be produced in ITB plasmas. Exploration of the relationship between the intrinsic rotation and the ITB temperature gradient leads to a novel scaling of intrinsic rotation in ITB plasmas. Long time power ramp simulations with self-consistently evolving profiles clearly demonstrate the existence of hysteresis in reversed shear ITBs. It is shown that intrinsic rotation plays an important role in ITB dynamics and is responsible for determining unique properties of ITB hysteresis. A negative feedback mechanism based on destruction of E × B shear prevails in barrier back transition, triggered by an outward momentum transport event during the power ramp down.

Unravelling the Conformational Landscape of Nicotinoids: the Structure of Cotinine by Broadband Rotational Spectroscopy

NASA Astrophysics Data System (ADS)

Uriarte, Iciar; Ecija, Patricia; Cocinero, Emilio J.; Perez, Cristobal; Caballero-Mancebo, Elena; Lesarri, Alberto

2015-06-01

Alkaloids such as nicotine, cotinine or anabasine share a common floppy structural motif consisting of a two-ring assembly with a 3-pyridil methylamine skeleton. In order to investigate the structure-activity relationship of these biomolecules, structural studies with rotational resolution have been carried out for nicotine and anabasine in the gas phase, where these molecules can be probed in an "interaction-free" environment (no solvent or crystal-packing interactions). We hereby present a structural investigation of cotinine in a jet expansion using the chirped-pulse Fourier-transform microwave (CP-FTMW) spectrometer recently built at the University of the Basque Country (UPV-EHU). The rotational spectrum (6-18 GHz) reveals the presence of two different conformations. The conformational preferences of cotinine originate from the internal rotation of the two ring moieties, the detected species differing in a near 180° rotation of pyridine. The final structure is modulated by steric effects. J.-U. Grabow, S. Mata, J. L. Alonso, I. Peña, S. Blanco, J. C. López, C. Cabezas, Phys. Chem. Chem. Phys. 2011, 13, 21063. A. Lesarri, E. J. Cocinero, L. Evangelisti, R. D. Suenram, W. Caminati, J.-U. Grabow, Chem. Eur. J. 2010, 16, 10214.

Intramolecular Hydrogen Bonding Restricts Gd-Aqua-Ligand Dynamics [The Day the Water Stood Still: Intramolecular Hydrogen Bonding to Restrict Gd-Aqua Ligand Dynamics

DOE PAGES

Boros, Eszter; Srinivas, Raja; Kim, Hee -Kyung; ...

2017-04-11

Aqua ligands can undergo rapid internal rotation about the M-O bond. For magnetic resonance contrast agents, this rotation results in diminished relaxivity. Herein, we show that an intramolecular hydrogen bond to the aqua ligand can reduce this internal rotation and increase relaxivity. Molecular modeling was used to design a series of four Gd complexes capable of forming an intramolecular H-bond to the coordinated water ligand, and these complexes had anomalously high relaxivities compared to similar complexes lacking a H-bond acceptor. Molecular dynamics simulations supported the formation of a stable intramolecular H-bond, while alternative hypotheses that could explain the higher relaxivitymore » were systematically ruled out. Finally, intramolecular H-bonding represents a useful strategy to limit internal water rotational motion and increase relaxivity of Gd complexes.« less

Internal Flow of Contra-Rotating Small Hydroturbine at Off- Design Flow Rates

NASA Astrophysics Data System (ADS)

SHIGEMITSU, Toru; TAKESHIMA, Yasutoshi; OGAWA, Yuya; FUKUTOMI, Junichiro

2016-11-01

Small hydropower generation is one of important alternative energy, and enormous potential lie in the small hydropower. However, efficiency of small hydroturbines is lower than that of large one. Then, there are demands for small hydroturbines to keep high performance in wide flow rate range. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance. In this research, performance of the contra-rotating small hydroturbine with 60mm casing diameter was investigated by an experiment and numerical analysis. Efficiency of the contra-rotating small hydroturbine was high in pico-hydroturbine and high efficiency could be kept in wide flow rate range, however the performance of a rear rotor decreased significantly in partial flow rates. Then, internal flow condition, which was difficult to measure experimentally, was investigated by the numerical flow analysis. Then, a relation between the performance and internal flow condition was considered by the numerical analysis result.

Probable Rotation States of Rocket Bodies in Low Earth Orbit

NASA Astrophysics Data System (ADS)

Ojakangas, G.; Anz-Meador, P.; Cowardin, H.

2012-09-01

In order for Active Debris Removal to be accomplished, it is critically important to understand the probable rotation states of orbiting, spent rocket bodies (RBs). However, rotational dynamics is non-intuitive and misconceptions are common. Determinations of rotation and precession rates from light curves have been published that are inconsistent with the theory presented here. In a state of free precession, the total angular momentum of the object is constant, while kinetic energy decreases due to internal friction, approaching rotation about the axis of maximum inertia. For solid internal friction the timescale is hundreds to thousands of years for quality factors of ~100 and assuming metallic rigidities, but for friction in partially-filled liquid fuel tanks we predict that the preferred rotational state is approached rapidly, within days to months. However, history has shown that theoretical predictions of the timescale have been notoriously inaccurate. In free precession, the 3-1-3 Euler angle rates dphi/dt (precession rate of long axis about fixed angular momentum with cone angle theta) and dpsi/dt (roll rate around long axis) have comparable magnitudes until very close to theta=pi/2, so that otherwise the true rotation period is not simply twice the primary light curve period. Furthermore dtheta/dt, nonzero due to friction, becomes asymptotically smaller as theta=pi/2 is approached, so that theta can linger within several degrees of flat spin for a relatively long time. Such a condition is likely common, and cannot be distinguished from the wobble of a cylinder with a skewed inertia tensor unless the RB has non-axisymmetric reflectivity characteristics. For an RB of known dimensions, a given value of theta fixes the relative values of dpsi/dt and dphi/dt. In forced precession, the angular momentum precesses about a symmetry axis defined by the relevant torque. However, in LEO, only gravity gradient and magnetic eddy current torques are dominant, and these cannot cause precession periods shorter than a week, or more likely, months. Thus forced precession is probably not observable over observation campaigns spanning a few days or less. Spin-orbit resonances are likely for low rotation rates approaching the mean motion, possibly causing large deviations between the symmetry axis and the geocentric direction. An expression for the eddy current torque on an arbitrarily rotating cylinder, hitherto not available in the literature, is presented here. Numerical integrations of the equations of motion for a cylindrical RB in LEO with arbitrary initial conditions and subject to eddy current and gravity gradient torques as well as prescribed internal dissipation are in progress. Acknowledgements: This work was produced under NASA contract NNJ05HI05.

Nuclear reactor

DOEpatents

Wade, Elman E.

1979-01-01

A nuclear reactor including two rotatable plugs and a positive top core holddown structure. The top core holddown structure is divided into two parts: a small core cover, and a large core cover. The small core cover, and the upper internals associated therewith, are attached to the small rotating plug, and the large core cover, with its associated upper internals, is attached to the large rotating plug. By so splitting the core holddown structures, under-the-plug refueling is accomplished without the necessity of enlarging the reactor pressure vessel to provide a storage space for the core holddown structure during refueling. Additionally, the small and large rotating plugs, and their associated core covers, are arranged such that the separation of the two core covers to permit rotation is accomplished without the installation of complex lifting mechanisms.

Modification of the sagittal split osteotomy of the mandibular ramus: mobilizing vertical osteotomy of the internal ramus segment.

PubMed

Ricard, Daniel; Ferri, Joël

2009-08-01

We describe a new surgical procedure to improve stability when counterclockwise rotation of the maxillomandibular complex and the occlusal plane is intended. This preliminary prospective study evaluated 10 patients (8 female patients and 2 male patients) who each underwent maxillomandibular surgical advancement with counterclockwise rotation of the occlusal plane. A mandibular counterclockwise rotation was done in all cases with bilateral ramus sagittal split osteotomy. After the split of the ramus had been completed, a vertical osteotomy was done distally to the second molar on the internal ramus segment. With the completion of this vertical osteotomy, the internal ramus segment became completely mobile. All osteotomies were stabilized with rigid internal fixation by use of plates with monocortical screws. Ten patients have been treated with the "mobilizing vertical osteotomy of the internal ramus segment." The mean reduction of the occlusal plane angle was 10.1 degrees , showing a substantial counterclockwise rotation of the maxillomandibular complex. All patients had significant improvement of their facial balance. After a 1-year follow-up period, all cases but 1 showed very good stability of their occlusion and occlusal plane angle. An 11.4% relapse of the forward movement of the mandible was noted. On the basis of this prospective study, we conclude that when performing a counterclockwise rotation of the maxillomandibular complex, the mobilizing vertical osteotomy of the internal ramus segment combined with the sagittal split osteotomy of the mandible potentially enhances the occlusal plane angle and occlusal stability after a 1-year period.

A Model Job Rotation Plan: A 10-Year Follow-up.

ERIC Educational Resources Information Center

Robinson, Daniel C.; Delbridge-Parker, Linda

1991-01-01

Describes model job rotation plan in a college student affairs division in which a staff member (intern) rotates among departments as a staff development opportunity. A 10-year follow-up evaluation underscored the success of the program. Concludes job rotation is not just learning experience, but it is also sharing experience. (Author/ABL)

Earth Rotation Parameters from DSN VLBI: 1994

NASA Technical Reports Server (NTRS)

Steppe, J. A.; Oliveau, S. H.; Sovers, O. J.

1994-01-01

In this report, Earth Rotation Parameter (ERP) estimates ahve been obtained from an analysis of Deep Space Network (DSN) VLBI data that directly aligns its celestial and terrestrial reference frames with those of the International Earth Rotation Service (IERS).

The Effects of Internal Rotation and 14N Quadrupole Coupling in N-Methyldiacetamide

NASA Astrophysics Data System (ADS)

Kannengießer, Raphaela; Eibl, Konrad; Nguyen, Ha Vinh Lam; Stahl, Wolfgang

2015-06-01

Acetyl- and nitrogen containing substances play an important role in chemical, physical, and especially biological systems. This applies in particular for acetamides, which are structurally related to peptide bonds. In this work, N-methyldiacetamide, CH_3N(COCH_3)_2, was investigated by a combination of molecular beam Fourier transform microwave spectroscopy and quantum chemical calculations. In N-methyldiacetamide, at least three large amplitude motions are possible: (1) the internal rotation of the methyl group attached to the nitrogen atom and (2, 3) the internal rotations of both acetyl methyl groups. This leads to a rather complicated torsional fine structure of all rotational transitions with additional quadrupole hyperfine splittings caused by the 14N nucleus. Quantum chemical calculations were carried out at the MP2/6-311++G(d,p) level of theory to support the spectral assignment. Conformational analysis was performed by calculating a full potential energy surface depending on the orientation of the two acetyl groups. This yielded three stable conformers with a maximum energy difference of 35.2 kJ/mol. The spectrum of the lowest energy conformer was identified in the molecular beam. The quadrupole hyperfine structure as well as the internal rotation of two methyl groups could be assigned. For the N-methyl group and for one of the two acetyl methyl groups, barriers to internal rotation of 147 cm-1 and of 680 cm-1, respectively, were determined. The barrier of the last methyl group seems to be so high that no additional splittings could be resolved. Using the XIAM program, a global fit with a standard deviation on the order of our experimental accuracy could be achieved.

Are professional handball players at risk for developing a glenohumeral internal rotation deficit in their dominant arm?

PubMed

Seabra, Pedro; Van Eck, Carola F; Sá, Márcia; Torres, João

2017-05-01

Overhead athletes, such as baseball players, have been shown to have adaptive changes in the shoulder range of motion (ROM) of their dominant arm. Professional handball players are a unique subtype of overhead athletes with very different demands from baseball players. The aim of this study was to determine if professional handball players demonstrate differences in shoulder ROM between their dominant and non-dominant arm and try to relate them with new variables. Fifty professional male handball players were included and completed a questionnaire regarding age at which they started to play, number of hours they practice a week, field position and arm dominance. ROM measurements were performed including forward flexion (FF), external rotation with the shoulder in abduction (ABER) and with adducted arm (ADER) and internal rotation with shoulder in abduction (IR). Statistical analysis was performed to determine differences in ROM between the dominant and non-dominant shoulder and if there is a relationship between these differences and shoulder load or field position. The dominant arm showed decreased internal rotation (47 vs. 56 degrees, p < 0.001) and increased external rotation both with the arm abducted (99 vs. 88 degrees, p < 0.001) and at the side (62 vs 57 degrees, p = 0.001). This was not correlated with shoulder load for any movement (FF, p = 0.980; ABER, p = 0.741; ADER, p = 0.803; IR, p = 0.085) but was dependent on field position with first line players showing the highest internal rotation deficit (13 degrees vs. 6-7 degrees in the other field positions, p = 0.013). This study showed that professional male handball players with a first line position have a significant risk for developing a glenohumeral internal rotation deficit, similar to the phenomenon seen in baseball pitchers.

Competitive internal transfers in metastable decay of cluster ions

NASA Astrophysics Data System (ADS)

Buonomo, E.; Gianturco, F. A.; Delgado-Barrio, G.; Miret-Artés, S.; Villarreal, P.

1994-05-01

In a previous study of fragmentation patterns of (Ar)+3 clusters [G. Delgado-Barrio, S. Miret-Artés, P. Villarreal, and F. A. Gianturco, Z. Phys. D 27, 354 (1993)] it was found that overall rotations control the lifetimes of the occupied metastable states of the cluster and that a spherical, effective interaction was sufficient to describe the dynamical process. In the present study, the strong anisotropy of a more realistic three-particle interaction is introduced and its effects on metastable decay are examined. By separating internal rotations from internal vibrations of the diatomic ion, it is possible to show that internal predissociation pathways are very efficient and lead to very short lifetimes. The latter can be lengthened only when overall rotational states are directly included, thus confirming the physical picture of the earlier work.

Comparison of reaction forces on the anterior cruciate and anterolateral ligaments during internal rotation and anterior drawer forces at different flexion angles of the knee joint.

PubMed

Uğur, Levent

2017-12-01

Having a complicated anatomy, the knee joint has been further detailed and a new formation defined, the anterolateral ligament (ALL), in recent studies. While the importance of this ligament, which previously was associated with Segond fractures, was explained via clinical, radiologic and biomechanical studies, and basically, is thought to be a fixator structures for the tibia against internal rotation stress. Although in recent studies efficient surgical treatment was applied to patients who underwent anterior cruciate ligament (ACL) operation, some patients having a positive pivot test highlights the clinical importance of the ALL. The aim of this study is to evaluate reaction forces of different flexion angles on the tibia during internal rotation and anterior drawer tests on both the ALL and ACL, and to examine theimportance of this ligament in knee biomechanics by a finite element analysis method. In this study, normal anatomy knee joint was modelled using Computed Tomography images from lower extremity length in DICOM format. 0°, 15°,30°,45°,60°,75° and 90° angles of flexion were applied, respectively, to these models and reaction force vectors formed on both ligaments were examined separately and as total vector and size by applying internal rotation and anterior drawer forces on each model. Non-linear analysis was conducted using ANSYS (version 17) with the same limit conditions applied to all models. After all models were examined, in general when comparing reaction forces, those on the ACL were found to be higher. However, when vectoral directions were examined, forces on ALL increased with increased flexion ratio and internal rotation momentum. Beyond 30° flexion, the tensile force on the ALL is increased and compressive overload on the ACL occurs. The ALL plays an important role in stability, especially against internal rotation forces, and an increased knee joint flexion ratio increases the stability contribution ratio. In particular, at 30° and higher angles, ACL reflects an antagonist effect and contributes to knee joint stability for rotational and mediolateral transposition. Copyright © 2017 John Wiley & Sons, Ltd.

The Effect of Glenohumeral Internal-Rotation Deficit on Functional Rotator-Strength Ratio in Adolescent Overhead Athletes.

PubMed

Guney, Hande; Harput, Gulcan; Colakoglu, Filiz; Baltaci, Gul

2016-02-01

Glenohumeral (GH) internal-rotation deficit (GIRD) and lower eccentric external-rotator (ER) to concentric internal-rotator (IR) strength (ER:IR) ratio have been documented as risk factors for shoulder injuries, but there is no information on whether GIRD has an adverse effect on ER:IR ratio in adolescent overhead athletes. The aim of this study was to investigate the effects of GIRD on functional ER:IR ratio of the adolescent overhead athletes. Cross-sectional study. University research laboratory. 52 adolescent overhead athletes. To determine GIRD, the range of GH IR and ER motion was measured with a digital inclinometer. An isokinetic dynamometer was used to assess eccentric and concentric IR and ER muscle strength of the dominant and nondominant shoulders. One-way ANCOVA where sport type was set as a covariate was used to analyze the difference between athletes with and without GIRD. After standardized examinations of all shoulders, the athletes were divided into 2 groups, shoulders with (n = 27) and without GIRD (n = 25). There was a significant difference between groups in functional ER:IR ratio (P < .001). Athletes with GIRD had lower ER:IR ratio (0.56) than athletes without GIRD (0.83). As GIRD has an adverse effect on functional ratio of the shoulder-rotator muscles, interventions for adolescent overhead athletes should include improving GH-rotation range of motion.

Relationship between femoroacetabular contact areas and hip position in the normal joint: an in vitro evaluation.

PubMed

Signorelli, Cecilia; Lopomo, Nicola; Bonanzinga, Tommaso; Marcheggiani Muccioli, Giulio Maria; Safran, Marc R; Marcacci, Maurilio; Zaffagnini, Stefano

2013-02-01

Different approaches have been proposed to diagnose femoroacetabular impingement (FAI) condition and hip instability. It is still debatable which test is the most effective to make a correct diagnosis. The true mechanics of the hip during particular physical examination manoeuvres is unknown. Eight fresh frozen hips were passively taken through 3 different commonly used positions for FAI diagnosis and hip instability: 90° Flexion-Adduction-Internal Rotation, Hyperextension-Adduction-External Rotation and Hyperextension-Neutral-External Rotation. Kinematics and anatomical data were acquired by an optoelectronic system. The contact areas between acetabulum and femoral head were analysed to determine whether these tests are able to localize regions of the hip that may give patients pain. In the hip positions where the femur was in Hyperextension-External Rotation, the contact area was mainly concentrated in the posterosuperior area of the acetabulum, while during 90° Flexion-Adduction-Internal Rotation position, there was a wider distribution of contact, not specific to the anterolateral acetabulum. The results confirm the ability of the Hyperextension-External Rotation tests to particularly analyse the posterior region of the acetabulum. Placing the hip in 90° of Flexion-Adduction-Internal Rotation allows for testing a wider zone of the acetabulum and is not specific to abutment of the femoral head-neck region against the anterolateral acetabulum.

Rotationally inelastic collisions of H2+ ions with He buffer gas: Computing cross sections and rates

NASA Astrophysics Data System (ADS)

Hernández Vera, Mario; Gianturco, F. A.; Wester, R.; da Silva, H.; Dulieu, O.; Schiller, S.

2017-03-01

We present quantum calculations for the inelastic collisions between H2+ molecules, in rotationally excited internal states, and He atoms. This work is motivated by the possibility of experiments in which the molecular ions are stored and translationally cooled in an ion trap and a He buffer gas is added for deactivation of the internal rotational population, in particular at low (cryogenic) translational temperatures. We carry out an accurate representation of the forces at play from an ab initio description of the relevant potential energy surface, with the molecular ion in its ground vibrational state, and obtain the cross sections for state-changing rotationally inelastic collisions by solving the coupled channel quantum scattering equations. The presence of hyperfine and fine structure effects in both ortho- and para-H2+ molecules is investigated and compared to the results where such a contribution is disregarded. An analysis of possible propensity rules that may predict the relative probabilities of inelastic events involving rotational state-changing is also carried out, together with the corresponding elastic cross sections from several initial rotational states. Temperature-dependent rotationally inelastic rates are then computed and discussed in terms of relative state-changing collisional efficiency under trap conditions. The results provide the essential input data for modeling different aspects of the experimental setups which can finally produce internally cold molecular ions interacting with a buffer gas.

Peptide conjugated magnetic nanoparticles for magnetically mediated energy delivery to lung cancer cells.

PubMed

Hauser, Anastasia K; Anderson, Kimberly W; Hilt, J Zach

2016-07-01

In the present study, we examine the effects of internalized peptide-conjugated iron oxide nanoparticles and their ability to locally convert alternating magnetic field (AMF) energy into other forms of energy (e.g., heat and rotational work). Dextran-coated iron oxide nanoparticles were functionalized with a cell penetrating peptide and after internalization by A549 and H358 cells were activated by an AMF. TAT-functionalized nanoparticles and AMF exposure increased reactive oxygen species generation compared with the nanoparticle system alone. The TAT-functionalized nanoparticles induced lysosomal membrane permeability and mitochondrial membrane depolarization, but these effects were not further enhanced by AMF treatment. Although not statistically significant, there are trends suggesting an increase in apoptosis via the Caspase 3/7 pathways when cells are exposed to TAT-functionalized nanoparticles combined with AMF. Our results indicate that internalized TAT-functionalized iron oxide nanoparticles activated by an AMF elicit cellular responses without a measurable temperature rise.

International Laser Ranging Service (ILRS) 2003-2004 Annual Report

NASA Technical Reports Server (NTRS)

Pearlman, Michael (Editor); Noll, Carey (Editor)

2005-01-01

The International Laser Ranging Service (ILRS) organizes and coordinates Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) to support programs in geodetic, geophysical, and lunar research activities and provides the International Earth Rotation and Reference Systems Service (IERS) with products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). This reference frame provides the stability through which systematic measurements of the Earth can be made over thousands of kilometers, decades of time, and evolution of measurement technology. This 2003-2004 ILRS annual report is comprised of individual contributions from ILRS components within the international geodetic community for the years 2003-2004. The report documents changes and progress of the ILRS and is also available on the ILRS Web site at http://ilrs.gsfc.nasa.gov/reports/ilrs_reports/ilrsar_2003.html.

The internal representation of head orientation differs for conscious perception and balance control

PubMed Central

Dalton, Brian H.; Rasman, Brandon G.; Inglis, J. Timothy

2017-01-01

Key points We tested perceived head‐on‐feet orientation and the direction of vestibular‐evoked balance responses in passively and actively held head‐turned postures.The direction of vestibular‐evoked balance responses was not aligned with perceived head‐on‐feet orientation while maintaining prolonged passively held head‐turned postures. Furthermore, static visual cues of head‐on‐feet orientation did not update the estimate of head posture for the balance controller.A prolonged actively held head‐turned posture did not elicit a rotation in the direction of the vestibular‐evoked balance response despite a significant rotation in perceived angular head posture.It is proposed that conscious perception of head posture and the transformation of vestibular signals for standing balance relying on this head posture are not dependent on the same internal representation. Rather, the balance system may operate under its own sensorimotor principles, which are partly independent from perception. Abstract Vestibular signals used for balance control must be integrated with other sensorimotor cues to allow transformation of descending signals according to an internal representation of body configuration. We explored two alternative models of sensorimotor integration that propose (1) a single internal representation of head‐on‐feet orientation is responsible for perceived postural orientation and standing balance or (2) conscious perception and balance control are driven by separate internal representations. During three experiments, participants stood quietly while passively or actively maintaining a prolonged head‐turned posture (>10 min). Throughout the trials, participants intermittently reported their perceived head angular position, and subsequently electrical vestibular stimuli were delivered to elicit whole‐body balance responses. Visual recalibration of head‐on‐feet posture was used to determine whether static visual cues are used to update the internal representation of body configuration for perceived orientation and standing balance. All three experiments involved situations in which the vestibular‐evoked balance response was not orthogonal to perceived head‐on‐feet orientation, regardless of the visual information provided. For prolonged head‐turned postures, balance responses consistent with actual head‐on‐feet posture occurred only during the active condition. Our results indicate that conscious perception of head‐on‐feet posture and vestibular control of balance do not rely on the same internal representation, but instead treat sensorimotor cues in parallel and may arrive at different conclusions regarding head‐on‐feet posture. The balance system appears to bypass static visual cues of postural orientation and mainly use other sensorimotor signals of head‐on‐feet position to transform vestibular signals of head motion, a mechanism appropriate for most daily activities. PMID:28035656

Scapular Stabilization and Muscle Strength in Manual Wheelchair Users with Spinal Cord Injury and Subacromial Impingement.

PubMed

Wilbanks, Susan R; Bickel, C Scott

2016-01-01

Background: Manual wheelchair users with spinal cord injury (SCI) are frequently diagnosed with subacromial impingement. Objective: To determine whether the pattern of muscle imbalance and impaired scapular stabilization in able-bodied (AB) adults with impingement is different from that in manual wheelchair users with SCI and impingement. Methods: The following measurements were collected from 22 adults with subacromial impingement (11 SCI, 11 AB): ratio of normalized muscle electrical activity of upper and lower trapezius (UT:LT) during arm abduction; force during abduction, adduction, internal rotation, external rotation, and push and pull; ratios of force for abduction to adduction (AB:ADD), internal to external rotation (IR:ER), and push to pull (PUSH:PULL). Results: Shoulders with impingement had significantly higher UT:LT activation (1.46 ± 0.52) than shoulders without impingement (0.93 ± 0.45) ( P = .006), regardless of wheelchair user status. Significant differences between AB participants and those with SCI were observed for ABD:ADD ( P = .005), PUSH:PULL ( P = .012), and pull strength ( P = .043). Participants with SCI had a significantly greater ABD:ADD (1.37 ± 0.36) than AB participants (1.04 ± 0.22) ( P = .002) and a significantly greater PUSH:PULL (1.53 ± 0.36) than AB participants (1.26 ± 0.18) ( P = .005) because of decreased strength in adduction ( P = .021) and pull ( P = .013). Conclusions: Strategies targeting the posterior shoulder girdle for AB adults are appropriate for manual wheelchair users with SCI and impingement and should focus on scapular retractors and arm adductors with emphasis on scapular depression and posterior tilting.

Two-dimensional character of internal rotation of furfural and other five-member heterocyclic aromatic aldehydes

NASA Astrophysics Data System (ADS)

Bataev, Vadim A.; Pupyshev, Vladimir I.; Godunov, Igor A.

2016-05-01

The features of nuclear motion corresponding to the rotation of the formyl group (CHO) are studied for the molecules of furfural and some other five-member heterocyclic aromatic aldehydes by the use of MP2/6-311G** quantum chemical approximation. It is demonstrated that the traditional one-dimensional models of internal rotation for the molecules studied have only limited applicability. The reason is the strong kinematic interaction of the rotation of the CHO group and out-of-plane CHO deformation that is realized for the molecules under consideration. The computational procedure based on the two-dimensional approximation is considered for low lying vibrational states as more adequate to the problem.

What we know about the sun's internal rotation from solar oscillations

NASA Technical Reports Server (NTRS)

Goode, Philip R.; Dziembowski, W. A.; Korzennik, S. G.; Rhodes, E. J., Jr.

1991-01-01

In this paper, a uniform approach of inversion was used to determine the internal rotation rate of the sun from each of the six available sets of solar oscillation data, which included the data of Duvall et al. (1986), Rhodes et al. (1987, 1990), Tomczyk (1988), Brown and Morrow (1987), and Libbrecht (1989). The technique chosen for inverting the solar oscillation data was the discretized least-squares technique. The results indicate that the rotation rate of the sun in the equatorial plane declines going inward between the surface and 0.6 of the radius and that the polar rate increases going inward (i.e., the surfacelike differential rotation decreases with depth).

Factors associated with intern noncompliance with the 2003 Accreditation Council for Graduate Medical Education's 30-hour duty period requirement.

PubMed

Maloney, Christopher G; Antommaria, Armand H Matheny; Bale, James F; Ying, Jian; Greene, Tom; Srivastava, Rajendu

2012-07-13

In 2003 the Accreditation Council for Graduate Medical Education mandated work hour restrictions. Violations can results in a residency program being cited or placed on probation. Recurrent violations could results in loss of accreditation. We wanted to determine specific intern and workload factors associated with violation of a specific mandate, the 30-hour duty period requirement. Retrospective review of interns' performance against the 30-hour duty period requirement during inpatient ward rotations at a pediatric residency program between June 24, 2008 and June 23, 2009. The analytical plan included both univariate and multivariable logistic regression analyses. Twenty of the 26 (77%) interns had 80 self-reported episodes of continuous work hours greater than 30 hours. In multivariable analysis, noncompliance was inversely associated with the number of prior inpatient rotations (odds ratio: 0.49, 95% confidence interval (0.38, 0.64) per rotation) but directly associated with the total number of patients (odds ratio: 1.30 (1.10, 1.53) per additional patient). The number of admissions on-call, number of admissions after midnight and number of discharges post-call were not significantly associated with noncompliance. The level of noncompliance also varied significantly between interns after accounting for intern experience and workload factors. Subject to limitations in statistical power, we were unable to identify specific intern characteristics, such as demographic variables or examination scores, which account for the variation in noncompliance between interns. Both intern and workload factors were associated with pediatric intern noncompliance with the 30-hour duty period requirement during inpatient ward rotations. Residency programs must develop information systems to understand the individual and experience factors associated with noncompliance and implement appropriate interventions to ensure compliance with the duty hour regulations.

Glenohumeral and Hip Range-of-Motion and Strength Measures in Youth Baseball Athletes

PubMed Central

Harding, Josie L.; Bliven, Kellie C. Huxel

2016-01-01

Context:  The repetitive demands of throwing affect glenohumeral (GH) range of motion (ROM) and strength. Less is known about hip alterations in skeletally immature athletes. Objective:  To compare GH and hip ROM and strength between age, position, and side of youth baseball athletes. Design:  Cross-sectional study. Setting:  Multicenter testing. Patients or Other Participants:  Seventy-two healthy baseball athletes. Participants' self-reported characteristics were age group (7−11 years [n = 28] or 12−18 years [n = 44]), position (pitcher [n = 22], position player [n = 47], unreported [n = 3]), and side (throwing or nonthrowing arm, lead or stance leg). Main Outcome Measure(s):  Bilateral GH and hip internal- and external-rotation ROM were measured passively and summed for total arc of motion (TAM). Glenohumeral and hip rotation and gluteus medius strength were measured. Analyses included linear mixed models. Results:  Glenohumeral internal rotation was less in throwing than in nonthrowing arms (P < .05) except in younger pitchers (P = .86). Compared with older athletes, younger athletes had more GH external rotation (103.3° ± 7.7° versus 97.5° ± 9.4°; P = .002), TAM (156.4° ± 8.7° versus 147.9° ± 10.9°; P = .04), and external rotation in throwing compared with nonthrowing arms (101.9° ± 1.2° versus 97.9° ± 1.1°; P < .001). Glenohumeral TAM was less in throwing than in nonthrowing arms (150.5° ± 2.1° versus 154.9° ± 1.3°; P = .01). Younger athletes had more hip internal rotation (38.9° ± 6.8° versus 31.2° ± 7.5°; P < .001) and TAM (68.4° ± 10.0° versus 60.7° ± 9.8°; P = .001) than older athletes. Lead-leg hip internal-rotation ROM was greater than in the stance leg (34.8° ± 8.9° versus 32.8° ± 7.7°; P = .01). Overall, older players were stronger than younger players (P < .05), and the throwing arm was stronger in internal rotation than the nonthrowing arm (10.12 ± 3.72 lb [4.59 ± 1.69 kg] versus 9.43 ± 3.18 lb [4.28 ± 1.44 kg]; P = .047). Conclusions:  Youth baseball athletes had typical GH ROM adaptations of less internal rotation and more external rotation in the throwing versus the nonthrowing arm. Greater ROM in younger athletes may be explained by prepubertal characteristics. We obtained hip-strength values in youth baseball athletes, and as expected, older athletes were stronger. PMID:27441948

Double Versus Single Tendon Transfers to Improve Shoulder Function in Brachial Plexus Birth Palsy.

PubMed

Greenhill, Dustin A; Smith, William R; Ramsey, F V; Kozin, Scott H; Zlotolow, Dan A

2017-03-27

In children with brachial plexus birth palsy (BPBP) undergoing tendon transfers to augment shoulder external rotation, it is unclear whether transfer of the latissimus dorsi with its combined latissimus dorsi and teres major (cLT) versus isolated teres major (iTM) tendon transfer yield different outcomes. Records of patients with BPBP who underwent shoulder tendon transfers to augment external rotation were retrospectively reviewed. Transfer type (cLT or iTM) was considered indiscriminate by virtue of surgeon preference. Modified Mallet Scale (mMS) and Active Movement Scale scores were recorded. Patients with <12 months' follow-up, C7 or lower palsy, humeral osteotomy, shoulder procedure(s) within 8 months, microsurgery within 1 year, or recurrent glenohumeral subluxation confirmed by postoperative imaging were excluded. Matched cohorts were identified within each tendon transfer group to yield similar preoperative shoulder function and glenohumeral alignment status. Outcomes for all tendon transfers as well as differences between cLT and iTM cohorts were analyzed. Among 121 cLT and 34 iTM transfers, 49 cLT and 14 iTM met the inclusion criteria. Subsequent matching of cohorts yielded 28 patients (14 cLT and 14 iTM). Average age at time of transfer was 3.0±1.4 years. Follow-up averaged 4.1±3.1 years. There were no statistically significant preoperative differences between cohorts, thus matching criteria were validated. Regardless of tendon(s) transferred, mMS external rotation improved (2.2 to 3.5, P<0.001), whereas mMS internal rotation decreased (3.8 to 3.2, P<0.001). When comparing matched cohorts, cLT transfer produced a greater mMS external rotation improvement than iTM (2.1 vs. 1.5, respectively; P=0.025). Loss of midline function (defined as mMS external rotation <3) occurred in 5 (35.7%) cLT and 2 (14.3%) iTM patients. Both cLT or iTM transfer are effective at augmenting shoulder external rotation in children with C5-C6 BPBP. Furthermore, cLT transfers may yield a larger improvement in external rotation in certain patients. However, both techniques slightly decrease shoulder internal rotation. Given that more total cLT patients lost midline function among matched cohorts, iTM transfer may still be considered when limited midline function is a concern. Level III.

Tibial rotation under combined in vivo loading after single- and double-bundle anterior cruciate ligament reconstruction.

PubMed

Tsarouhas, Alexander; Iosifidis, Michael; Spyropoulos, Giannis; Kotzamitelos, Dimitrios; Tsatalas, Themistoklis; Giakas, Giannis

2011-12-01

To evaluate in vivo the differences in tibial rotation between single- and double-bundle anterior cruciate ligament (ACL)-reconstructed knees under combined loading conditions. An 8-camera optoelectronic system and a force plate were used to collect kinematic and kinetic data from 14 patients with double-bundle ACL reconstruction, 14 patients with single-bundle reconstruction, 12 ACL-deficient subjects, and 12 healthy control individuals while performing 2 tasks. The first included walking, 60° pivoting, and stair ascending, and the second included stair descending, 60° pivoting, and walking. The 2 variables evaluated were the maximum range of internal-external tibial rotation and the maximum knee rotational moment. Tibial rotation angles were not significantly different across the 4 groups (P = .331 and P = .851, respectively) or when side-to-side differences were compared within groups (P = .216 and P = .371, respectively) for the ascending and descending maneuvers, nor were rotational moments among the 4 groups (P = .418 and P = .290, respectively). Similarly, for the descending maneuver, the rotational moments were not significantly different between sides (P = .192). However, for the ascending maneuver, rotational moments of the affected sides were significantly lower by 20.5% and 18.7% compared with their intact counterparts in the single-bundle (P = .015) and double-bundle (P = .05) groups, respectively. High-intensity activities combining stair ascending or descending with pivoting produce similar tibial rotation in single- and double-bundle ACL-reconstructed patients. During such maneuvers, the reconstructed knee may be subjected to significantly lower rotational loads compared with the intact knee. Level III, retrospective comparative study. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Biomechanical effects of humeral neck-shaft angle and subscapularis integrity in reverse total shoulder arthroplasty.

PubMed

Oh, Joo Han; Shin, Sang-Jin; McGarry, Michelle H; Scott, Jonathan H; Heckmann, Nathanael; Lee, Thay Q

2014-08-01

The variability in functional outcomes and the occurrence of scapular notching and instability after reverse total shoulder arthroplasty remain problems. The objectives of this study were to measure the effect of reverse humeral component neck-shaft angle on impingement-free range of motion, abduction moment, and anterior dislocation force and to evaluate the effect of subscapularis loading on dislocation force. Six cadaveric shoulders were tested with 155°, 145°, and 135° reverse shoulder humeral neck-shaft angles. The adduction angle at which bone contact occurred and the internal and external rotational impingement-free range of motion angles were measured. Glenohumeral abduction moment was measured at 0° and 30° of abduction, and anterior dislocation forces were measured at 30° of internal rotation, 0°, and 30° of external rotation with and without subscapularis loading. Adduction deficit angles for 155°, 145°, and 135° neck-shaft angle were 2° ± 5° of abduction, 7° ± 4° of adduction, and 12° ± 2° of adduction (P < .05). Impingement-free angles of humeral rotation and abduction moments were not statistically different between the neck-shaft angles. The anterior dislocation force was significantly higher for the 135° neck-shaft angle at 30° of external rotation and significantly higher for the 155° neck-shaft angle at 30° of internal rotation (P < .01). The anterior dislocation forces were significantly higher when the subscapularis was loaded (P < .01). The 155° neck-shaft angle was more prone to scapular bone contact during adduction but was more stable at the internally rotated position, which was the least stable humeral rotation position. Subscapularis loading gave further anterior stability with all neck-shaft angles at all positions. Published by Mosby, Inc.

Shoulder-Rotator Strength, Range of Motion, and Acromiohumeral Distance in Asymptomatic Adolescent Volleyball Attackers

PubMed Central

Harput, Gulcan; Guney, Hande; Toprak, Ugur; Kaya, Tunca; Colakoglu, Fatma Filiz; Baltaci, Gul

2016-01-01

Context: Sport-specific adaptations at the glenohumeral joint could occur in adolescent athletes because they start participating in high-performance sports in early childhood. Objective: To investigate shoulder-rotator strength, internal-rotation (IR) and external-rotation (ER) range of motion (ROM), and acromiohumeral distance (AHD) in asymptomatic adolescent volleyball attackers to determine if they have risk factors for injury. Design: Cross-sectional study. Setting: University laboratory. Participants: Thirty-nine adolescent high school-aged volleyball attackers (22 boys, 17 girls; age = 16.0 ± 1.4 years, height = 179.2 ± 9.0 cm, mass = 67.1 ± 10.9 kg, body mass index = 20.7 ± 2.6 kg/m2). Main Outcome Measure(s): Shoulder IR and ER ROM, total-rotation ROM, glenohumeral IR deficit, AHD, and concentric and eccentric strength of the shoulder internal and external rotators were tested bilaterally. Results: External-rotation ROM was greater (t38 = 4.92, P < .001), but IR ROM (t38 = −8.61, P < .001) and total ROM (t38 = −3.55, P = .01) were less in the dominant shoulder, and 15 athletes had a glenohumeral IR deficit (IR ROM loss > 18°). We observed greater concentric internal-rotator (t38 = 2.89, P = .006) and eccentric external-rotator (t38 = 2.65, P = .01) strength in the dominant than in the nondominant shoulder. The AHD was less in the dominant shoulder (t38 = −3.60, P < .001). Conclusions: Adolescent volleyball attackers demonstrated decreased IR ROM, total ROM, and AHD and increased ER ROM in their dominant shoulder. Therefore, routine screening of adolescent athletes and designing training programs for hazardous adaptive changes could be important in preventing shoulder injuries. PMID:27813683

Shoulder-Rotator Strength, Range of Motion, and Acromiohumeral Distance in Asymptomatic Adolescent Volleyball Attackers.

PubMed

Harput, Gulcan; Guney, Hande; Toprak, Ugur; Kaya, Tunca; Colakoglu, Fatma Filiz; Baltaci, Gul

2016-09-01

Sport-specific adaptations at the glenohumeral joint could occur in adolescent athletes because they start participating in high-performance sports in early childhood. To investigate shoulder-rotator strength, internal-rotation (IR) and external-rotation (ER) range of motion (ROM), and acromiohumeral distance (AHD) in asymptomatic adolescent volleyball attackers to determine if they have risk factors for injury. Cross-sectional study. University laboratory. Thirty-nine adolescent high school-aged volleyball attackers (22 boys, 17 girls; age = 16.0 ± 1.4 years, height = 179.2 ± 9.0 cm, mass = 67.1 ± 10.9 kg, body mass index = 20.7 ± 2.6 kg/m 2 ). Shoulder IR and ER ROM, total-rotation ROM, glenohumeral IR deficit, AHD, and concentric and eccentric strength of the shoulder internal and external rotators were tested bilaterally. External-rotation ROM was greater (t 38 = 4.92, P < .001), but IR ROM (t 38 = -8.61, P < .001) and total ROM (t 38 = -3.55, P = .01) were less in the dominant shoulder, and 15 athletes had a glenohumeral IR deficit (IR ROM loss > 18°). We observed greater concentric internal-rotator (t 38 = 2.89, P = .006) and eccentric external-rotator (t 38 = 2.65, P = .01) strength in the dominant than in the nondominant shoulder. The AHD was less in the dominant shoulder (t 38 = -3.60, P < .001). Adolescent volleyball attackers demonstrated decreased IR ROM, total ROM, and AHD and increased ER ROM in their dominant shoulder. Therefore, routine screening of adolescent athletes and designing training programs for hazardous adaptive changes could be important in preventing shoulder injuries.

Molecular motions of [Beta]-carotene and a carotenoporphyrin dyad in solution. A carbon-13 NMR spin-lattice relaxation time study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, S.; Swindle, S.L.; Smith, S.K.

1995-03-09

Analysis of [sup 13]C NMR spin-lattice relaxation times (T[sub 1]) yields information concerning both overall tumbling of molecules in solution and internal rotations about single bonds. Relaxation time and nuclear Overhauser effect data have been obtained for [Beta]-carotene and two related molecules, squalane and squalene, for zinc meso-tetraphenylporphyrin, and for a dyad consisting of a porphyrin covalently linked to a carotenoid polyene through a trimethylene bridge. Squalane and squalene, which lack conjugated double bonds, behave essentially as limp string, with internal rotations at least as rapid as overall isotropic tumbling motions. In contrast, [Beta]-carotene reorients as a rigid rod, withmore » internal motions which are too slow to affect relaxation times. Modeling it as an anisotropic rotor yields a rotational diffusion coefficient for motion about the major axis which is 14 times larger than that for rotation about axes perpendicular to that axis. The porphyrin reorients more nearly isotropically and features internal librational motions about the single bonds to the phenyl groups. The relaxation time data for the carotenoporphyrin are consistent with internal motions similar to those of a medieval military flail. 31 refs., 3 figs., 5 tabs.« less

Active vortex sampling system for remote contactless survey of surfaces by laser-based field asymmetrical ion mobility spectrometer

NASA Astrophysics Data System (ADS)

Akmalov, Artem E.; Chistyakov, Alexander A.; Kotkovskii, Gennadii E.; Sychev, Alexei V.

2017-10-01

The ways for increasing the distance of non-contact sampling up to 40 cm for a field asymmetric ion mobility (FAIM) spectrometer are formulated and implemented by the use of laser desorption and active shaper of the vortex flow. Numerical modeling of air sampling flows was made and the sampling device for a laser-based FAIM spectrometer on the basis of high speed rotating impeller, located coaxial with the ion source, was designed. The dependence of trinitrotoluene vapors signal on the rotational speed and the optimization of the value of the sampling flow were obtained. The effective distance of sampling is increased up to 28 cm for trinitrotoluene vapors detection by a FAIM spectrometer with a rotating impeller. The distance is raised up to 40 cm using laser irradiation of traces of explosives. It is shown that efficient desorption of low-volatile explosives is achieved at laser intensity 107 W / cm2 , wavelength λ=266 nm, pulse energy about 1mJ and pulse frequency not less than 10 Hz under ambient conditions. The ways of optimization of internal gas flows of a FAIM spectrometer for the work at increased sampling distances are discussed.

Ready or not, here they come: acting interns' experience and perceived competency performing basic medical procedures.

PubMed

Coberly, LeAnn; Goldenhar, Linda M

2007-04-01

To assess acting interns' (AI's) experience with and perceived level of competency performing 6 basic medical procedures. Fourth-year medical students at the University of Cincinnati (UCCOM) are required to complete 2 AI rotations in Internal Medicine. All AIs in 2003-2004 (n = 150) and 2004-2005 (n = 151) were asked to complete a survey about whether during each of their rotations they had performed and felt competent performing the following procedures: phlebotomy, intravenous (IV) catheter insertion, arterial blood gas (ABG), nasogastric (NG) tube insertion, lumbar puncture (LP), and Foley catheter insertion. Four hundred sixty-seven of 601 possible surveys (across both years and both rotations) were completed (78% response rate). During both rotations, relatively few students performed the procedures, ranging from 9% for Foley catheter insertion (24/208) to 50% for both ABG and NG tube insertion (130/259). The two procedures most often performed were ABG (range 46-50%) and NG tube insertion (range 42-50%). Feelings of competency varied from 12% (LP) to 82% (Foley catheter). Except for LP, if students performed a procedure at least once, they reported feeling more competent (range 85% for ABG to 96% for Foley catheter insertion). Among the students who performed LP during a rotation, many still did not feel competent performing LPs: 23 (74%) in rotation 1 and 20 (40%) in rotation 2. Many fourth-year students at UCCOM do not perform basic procedures during their acting internship rotations. Procedural performance correlates with feelings of competency. Lumbar puncture competency may be too ambitious a goal for medical students.

IMPLICATIONS OF RAPID CORE ROTATION IN RED GIANTS FOR INTERNAL ANGULAR MOMENTUM TRANSPORT IN STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tayar, Jamie; Pinsonneault, Marc H., E-mail: tayar.1@osu.edu

2013-09-20

Core rotation rates have been measured for red giant stars using asteroseismology. These data, along with helioseismic measurements and open cluster spin-down studies, provide powerful clues about the nature and timescale for internal angular momentum transport in stars. We focus on two cases: the metal-poor red giant KIC 7341231 ({sup O}tto{sup )} and intermediate-mass core helium burning stars. For both, we examine limiting case studies for angular momentum coupling between cores and envelopes under the assumption of rigid rotation on the main sequence. We discuss the expected pattern of core rotation as a function of mass and radius. In themore » case of Otto, strong post-main-sequence coupling is ruled out and the measured core rotation rate is in the range of 23-33 times the surface value expected from standard spin-down models. The minimum coupling timescale (0.17-0.45 Gyr) is significantly longer than that inferred for young open cluster stars. This implies ineffective internal angular momentum transport in early first ascent giants. By contrast, the core rotation rates of evolved secondary clump stars are found to be consistent with strong coupling given their rapid main-sequence rotation. An extrapolation to the white dwarf regime predicts rotation periods between 330 and 0.0052 days, depending on mass and decoupling time. We identify two key ingredients that explain these features: the presence of a convective core and inefficient angular momentum transport in the presence of larger mean molecular weight gradients. Observational tests that can disentangle these effects are discussed.« less

Rotational molding of pultruded profiles reinforced polyethylene

NASA Astrophysics Data System (ADS)

Greco, Antonio; Maffezzoli, Alfonso; Romano, Giorgio

2014-05-01

The aim of this paper is the production of fiber reinforced LLDPE components by rotational molding. To this purpose, a process upgrade was developed, for the incorporation of pultruded tapes in the rotational molding cycle. Pultruded tapes, made of 50% by weight of glass fibers dispersed in a high density polyethylene(HDPE) matrix, were glued on the internal surface of a cubic mold, and rotational molding process was run using the same processing conditions used for conventional LLDPE processing. During processing, melting of LLDPE powders and of HDPE allowed to incorporate the tapes inside rotational molded LLDPE. The glass fiber reinforced prototypes were characterized in terms of mechanical properties. Plate bending tests were performed on the square faces extracted from the rotational molded product. The rotational molding products were also subjected to internal hydrostatic pressure tests up to 10 bar. In any case, no failure of the cubic samples was observed. In both cases, it was found that addition of a single pultruded strips, which corresponds to addition of about 0.6% by weight of glass fibers, involved an increase of the stiffness of the faces by about 25%.

Internal Medicine Residents' Clinical and Didactic Experiences After Work Hour Regulation

PubMed Central

Horwitz, Leora I; Krumholz, Harlan M; Huot, Stephen J; Green, Michael L

2006-01-01

BACKGROUND Work hour regulations for house staff were intended in part to improve resident clinical and educational performance. OBJECTIVE To characterize the effect of work hour regulation on internal medicine resident inpatient clinical experience and didactic education. DESIGN Cross-sectional mail survey. PARTICIPANTS Chief residents at all accredited U.S. internal medicine residency programs outside New York. MEASUREMENTS AND MAIN RESULTS The response rate was 62% (202/324). Most programs (72%) reported no change in average patient load per intern after work hour regulation. Many programs (48%) redistributed house staff admissions through the call cycle. The number of admissions per intern on long call (the day interns have the most admitting responsibility) decreased in 31% of programs, and the number of admissions on other days increased in 21% of programs. Residents on outpatient rotations were given new ward responsibilities in 36% of programs. Third-year resident ward and float time increased in 34% of programs, while third-year elective time decreased in 22% of programs. The mean weekly hours allotted to educational activities did not change significantly (12.7 vs 12.4, P = .12), but 56% of programs reported a decrease in intern attendance at educational activities. CONCLUSIONS In response to work hour regulation, many internal medicine programs redistributed rather than reduced residents' inpatient clinical experience. Hours allotted to educational activities did not change; however, most programs saw a decrease in intern attendance at conferences, and many reduced third-year elective time. PMID:16918742

Internal medicine residents' clinical and didactic experiences after work hour regulation: a survey of chief residents.

PubMed

Horwitz, Leora I; Krumholz, Harlan M; Huot, Stephen J; Green, Michael L

2006-09-01

Work hour regulations for house staff were intended in part to improve resident clinical and educational performance. To characterize the effect of work hour regulation on internal medicine resident inpatient clinical experience and didactic education. Cross-sectional mail survey. Chief residents at all accredited U.S. internal medicine residency programs outside New York. The response rate was 62% (202/324). Most programs (72%) reported no change in average patient load per intern after work hour regulation. Many programs (48%) redistributed house staff admissions through the call cycle. The number of admissions per intern on long call (the day interns have the most admitting responsibility) decreased in 31% of programs, and the number of admissions on other days increased in 21% of programs. Residents on outpatient rotations were given new ward responsibilities in 36% of programs. Third-year resident ward and float time increased in 34% of programs, while third-year elective time decreased in 22% of programs. The mean weekly hours allotted to educational activities did not change significantly (12.7 vs 12.4, P = .12), but 56% of programs reported a decrease in intern attendance at educational activities. In response to work hour regulation, many internal medicine programs redistributed rather than reduced residents' inpatient clinical experience. Hours allotted to educational activities did not change; however, most programs saw a decrease in intern attendance at conferences, and many reduced third-year elective time.

Factors associated with intern noncompliance with the 2003 Accreditation Council for Graduate Medical Education’s 30-hour duty period requirement

PubMed Central

2012-01-01

Background In 2003 the Accreditation Council for Graduate Medical Education mandated work hour restrictions. Violations can results in a residency program being cited or placed on probation. Recurrent violations could results in loss of accreditation. We wanted to determine specific intern and workload factors associated with violation of a specific mandate, the 30-hour duty period requirement. Methods Retrospective review of interns’ performance against the 30-hour duty period requirement during inpatient ward rotations at a pediatric residency program between June 24, 2008 and June 23, 2009. The analytical plan included both univariate and multivariable logistic regression analyses. Results Twenty of the 26 (77%) interns had 80 self-reported episodes of continuous work hours greater than 30 hours. In multivariable analysis, noncompliance was inversely associated with the number of prior inpatient rotations (odds ratio: 0.49, 95% confidence interval (0.38, 0.64) per rotation) but directly associated with the total number of patients (odds ratio: 1.30 (1.10, 1.53) per additional patient). The number of admissions on-call, number of admissions after midnight and number of discharges post-call were not significantly associated with noncompliance. The level of noncompliance also varied significantly between interns after accounting for intern experience and workload factors. Subject to limitations in statistical power, we were unable to identify specific intern characteristics, such as demographic variables or examination scores, which account for the variation in noncompliance between interns. Conclusions Both intern and workload factors were associated with pediatric intern noncompliance with the 30-hour duty period requirement during inpatient ward rotations. Residency programs must develop information systems to understand the individual and experience factors associated with noncompliance and implement appropriate interventions to ensure compliance with the duty hour regulations. PMID:22621439

Idling speed control system of an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyazaki, M.; Ishii, M.; Kako, H.

1986-09-16

This patent describes an idling speed control system of an internal combustion engine comprising: a valve device which controls the amount of intake air for the engine; an actuator which includes an electric motor for variably controlling the opening of the value device; rotation speed detector means for detecting the rotation speed of the engine; idling condition detector means for detecting the idling condition of the engine; feedback control means responsive to the detected output of the idling condition detector means for generating feedback control pulses to intermittently drive the electric motor so that the detected rotation speed of themore » engine under the idling condition may converge into a target idling rotation speed; and control means responsive to the output of detector means that detects an abnormally low rotation speed of the engine detected by the rotation speed detector means for generating control pulses that do not overlap the feedback control pulses to drive the electric motor in a predetermined direction.« less

Internal transport barrier dynamics with plasma rotation in JET

NASA Astrophysics Data System (ADS)

de Vries, P. C.; Joffrin, E.; Brix, M.; Challis, C. D.; Crombé, K.; Esposito, B.; Hawkes, N. C.; Giroud, C.; Hobirk, J.; Lönnroth, J.; Mantica, P.; Strintzi, D.; Tala, T.; Voitsekhovitch, I.; JET-EFDA Contributors to the Work Programme

2009-07-01

At JET the dynamics of internal transport barriers (ITBs) has been explored by trying to decouple the effects of heating on the one hand and torque on the other with the ultimate objective of identifying the minimum torque required for the formation of transport barriers. The experiments shed light on the physics behind the initial trigger for ITBs, which often shows to be linked to the shape of the q profile and magnetic shear, while the further development was influenced by the strength of the rotational shear. In discharges with a small amount of rotational shear ITBs were triggered, which suggest that the overall rotational shear is not the dominant factor in the triggering process. However, the subsequent growth of the barrier was limited if the rotational shear was too low at the time of triggering. This growth phase may be highly non-linear, with several possible positive feedback loops, such as the increases in the toroidal and poloidal component of the rotational shear caused by the ITB itself.

Cause and solution for false upstream boat velocities measured with a StreamPro acoustic doppler current profiler

USGS Publications Warehouse

Mueller, David S.; Rehmel, Mike S.; Wagner, Chad R.

2007-01-01

In 2003, Teledyne RD Instruments introduced the StreamPro acoustic Doppler current profiler which does not include an internal compass. During stationary moving-bed tests the StreamPro often tends to swim or kite from the end of the tether (the instrument rotates then moves laterally in the direction of the rotation). Because the StreamPro does not have an internal compass, it cannot account for the rotation. This rotation and lateral movement of the StreamPro on the end of the tether generates a false upstream velocity, which cannot be easily distinguished from a moving-bed bias velocity. A field test was completed to demonstrate that this rotation and lateral movement causes a false upstream boat velocity. The vector dot product of the boat velocity and the unit vector of the depth-averaged water velocity is shown to be an effective method to account for the effect of the rotation and lateral movement.

Effects of Fatigue on Driving Safety: A Comparison of Brake Reaction Times in Night Float and Postcall Physicians in Training.

PubMed

Talusan, Paul G; Long, Theodore; Halim, Andrea; Guliani, Laura; Carroll, Nicole; Reach, John

2014-12-01

Concerns about duty hour and resident safety have fostered discussion about postshift fatigue and driving impairment. We assessed how converting to a night float schedule for overnight coverage affected driving safety for trainees. Brake reaction times were measured for internal medicine and orthopaedic surgery resident volunteers after a traditional 28-hour call shift and after a night float shift. We conducted matched paired t tests of preshift and postshift reaction time means. Participants also completed the Epworth Sleepiness Scale pre- and postshift. From June to July 2013, we enrolled 58 interns and residents (28 orthopaedic surgery, 30 internal medicine). We included 24 (41%) trainees on night float rotations and 34 (59%) trainees on traditional 28-hour call shifts. For all residents on night float rotations, there was no significant difference pre- and postshift. An increase in reaction times was noted among trainees on 28-hour call rotations. This included no effect on reaction times for internal medicine trainees pre- and postshift, and an increase in reaction times for orthopaedic trainees. For both night float and traditional call groups, there were significant increases in the Epworth Sleepiness Scale. Trainees on traditional 28-hour call rotations had significantly worse postshift brake reaction times, whereas trainees on night float rotations had no difference. Orthopaedic trainees had significant differences in brake reaction times after a traditional call shift.

Linear Theory of a Projectile With a Rotating Internal Part in Atmospheric Flight

DTIC Science & Technology

2003-07-01

shape, or form. Fuze mechanisms used on some indirect fire ammunition employ a rotor that is permitted to move slightly with respect to the main...series of experiments where a projectile with a loose internal part was driven by the rotor of a freely gimbaled gyroscope. The gyroscope yaw history...cases, weapon system designers require guidance on the effect of the rotating internal part as well as guidance on how to optimally configure such a

Two-dimensional character of internal rotation of furfural and other five-member heterocyclic aromatic aldehydes.

PubMed

Bataev, Vadim A; Pupyshev, Vladimir I; Godunov, Igor A

2016-05-15

The features of nuclear motion corresponding to the rotation of the formyl group (CHO) are studied for the molecules of furfural and some other five-member heterocyclic aromatic aldehydes by the use of MP2/6-311G** quantum chemical approximation. It is demonstrated that the traditional one-dimensional models of internal rotation for the molecules studied have only limited applicability. The reason is the strong kinematic interaction of the rotation of the CHO group and out-of-plane CHO deformation that is realized for the molecules under consideration. The computational procedure based on the two-dimensional approximation is considered for low lying vibrational states as more adequate to the problem. Copyright © 2016 Elsevier B.V. All rights reserved.

Stability Control of Grasping Objects with Different Locations of Center of Mass and Rotational Inertia

PubMed Central

Slota, Gregory P.; Suh, Moon Suk; Latash, Mark L.; Zatsiorsky, Vladimir M.

2012-01-01

The objective of this study was to observe how the digits of the hand adjust to varying location of the center of mass (CoM) above/below the grasp and rotational inertia (RI) of a hand held object. Such manipulations do not immediately affect the equilibrium equations while stability control is affected. Participants were instructed to hold a handle, instrumented with five force/torque transducers and a 3-D rotational tilt sensor, while either the location of the CoM or the RI values were adjusted. On the whole, people use two mechanisms to adjust to the changed stability requirements; they increase the grip force and redistribute the total moment between the normal and tangential forces offsetting internal torques. The increase in grip force, an internal force, and offsetting internal torques allows for increases in joint and hand rotational apparent stiffness while not creating external forces/torques which would unbalance the equations of equilibrium. PMID:22456054

Not all anxious individuals get lost: Trait anxiety and mental rotation ability interact to explain performance in map-based route learning in men.

PubMed

Thoresen, John C; Francelet, Rebecca; Coltekin, Arzu; Richter, Kai-Florian; Fabrikant, Sara I; Sandi, Carmen

2016-07-01

Navigation through an environment is a fundamental human activity. Although group differences in navigational ability are documented (e.g., gender), little is known about traits that predict these abilities. Apart from a well-established link between mental rotational abilities and navigational learning abilities, recent studies point to an influence of trait anxiety on the formation of internal cognitive spatial representations. However, it is unknown whether trait anxiety affects the processing of information obtained through externalized representations such as maps. Here, we addressed this question by taking into account emerging evidence indicating impaired performance in executive tasks by high trait anxiety specifically in individuals with lower executive capacities. For this purpose, we tested 104 male participants, previously characterised on trait anxiety and mental rotation ability, on a newly-designed map-based route learning task, where participants matched routes presented dynamically on a city map to one presented immediately before (same/different judgments). We predicted an interaction between trait anxiety and mental rotation ability, specifically that performance in the route learning task would be negatively affected by anxiety in participants with low mental rotation ability. Importantly, and as predicted, an interaction between anxiety and mental rotation ability was observed: trait anxiety negatively affected participants with low-but not high-mental rotation ability. Our study reveals a detrimental role of trait anxiety in map-based route learning and specifies a disadvantage in the processing of map representations for high-anxious individuals with low mental rotation abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

Multi-scale phenomena of rotation-modified mode-2 internal waves

NASA Astrophysics Data System (ADS)

Deepwell, David; Stastna, Marek; Coutino, Aaron

2018-03-01

We present high-resolution, three-dimensional simulations of rotation-modified mode-2 internal solitary waves at various rotation rates and Schmidt numbers. Rotation is seen to change the internal solitary-like waves observed in the absence of rotation into a leading Kelvin wave followed by Poincaré waves. Mass and energy is found to be advected towards the right-most side wall (for a Northern Hemisphere rotation), leading to increased amplitude of the leading Kelvin wave and the formation of Kelvin-Helmholtz (K-H) instabilities on the upper and lower edges of the deformed pycnocline. These fundamentally three-dimensional instabilities are localized within a region near the side wall and intensify in vigour with increasing rotation rate. Secondary Kelvin waves form further behind the wave from either resonance with radiating Poincaré waves or the remnants of the K-H instability. The first of these mechanisms is in accord with published work on mode-1 Kelvin waves; the second is, to the best of our knowledge, novel to the present study. Both types of secondary Kelvin waves form on the same side of the channel as the leading Kelvin wave. Comparisons of equivalent cases with different Schmidt numbers indicate that while adopting a numerically advantageous low Schmidt number results in the correct general characteristics of the Kelvin waves, excessive diffusion of the pycnocline and various density features precludes accurate representation of both the trailing Poincaré wave field and the intensity and duration of the Kelvin-Helmholtz instabilities.

Navigation-based femorotibial rotation pattern correlated with flexion angle after total knee arthroplasty.

PubMed

Ishida, Kazunari; Shibanuma, Nao; Matsumoto, Tomoyuki; Sasaki, Hiroshi; Takayama, Koji; Matsuzaki, Tokio; Tei, Katsumasa; Kuroda, Ryosuke; Kurosaka, Masahiro

2016-01-01

To investigate whether intraoperative kinematics obtained by navigation systems can be divided into several kinematic patterns and to assess the correlation between the intraoperative kinematics with maximum flexion angles before and after total knee arthroplasty (TKA). Fifty-four posterior-stabilised (PS) TKA implanted using an image-free navigation system were evaluated. At registration and after implantation, tibial internal rotation angles at maximum extension, 30°, 45°, 60°, 90°, and maximum flexion were collected. The rotational patterns were divided into four groups and were examined the correlation with maximum flexion before and after operation. Tibial internal rotation from 90° of flexion to maximum flexion at registration was correlated with maximum flexion angles pre- and postoperatively. The four groups showed statistically different kinematic patterns. The group with tibial external rotation up to 90° of flexion, following tibial internal rotation at registration, achieved better flexion angles, compared to those of another groups (126.7° ± 12.0°, p < 0.05). The group with tibial external rotation showed the worst flexion angles (80.0° ± 40.4°, p < 0.05). Furthermore, the group with limited extension showed worse flexion angles (111.6° ± 8.9°, p < 0.05). Navigation-based kinematic patterns found at registration predict postoperative maximum flexion angle in PS TKA. Navigation-based kinematics can be useful information during TKA surgery. Diagnostic studies, development of diagnostic criteria in a consecutive series of patients and a universally applied "gold" standard, Level II.

First High Resolution Analysis of the ν21 Band of Propane at 921.4 wn: Evidence of Large-Amplitude Tunnelling Effects

NASA Astrophysics Data System (ADS)

Perrin, Agnes; Kwabia Tchana, F.; Flaud, Jean-Marie; Manceron, Laurent; Demaison, Jean; Vogt, Natalja; Groner, Peter; Lafferty, Walter

2015-06-01

A high resolution (0.0015 wn) IR spectrum of propane, C_3H_8, has been recorded with synchrotron radiation at the French light source facility at SOLEIL coupled to a Bruker IFS-125 Fourier transform spectrometer. A preliminary analysis of the ν21 fundamental band (B1, CH3 rock) near 921.4 wn reveals that the rotational energy levels of 211 are split by interactions with the internal rotations of the methyl groups. Conventional analysis of this A-type band yielded band centers at 921.3724(38), 921.3821(33) and 921.3913(44) wn for the AA, EE and AE+EA tunneling splitting components, respectively. These torsional splittings most probably are due to anharmonic and/or Coriolis resonance coupling with nearby highly excited states of both internal rotations of the methyl groups. In addition, several vibrational-rotational resonances were observed that affect the torsional components in different ways. The analysis of the B-type band near 870 wn (ν8, sym. C-C stretch) which also contains split rovibrational transitions due to internal rotation is in progress. It is performed by using the effective rotational Hamiltonian method ERHAM with a code that allows prediction and least-squares fitting of such vibration-rotation spectra. A. Perrin et al., submitted to J. Mol. Spectrosc. P. Groner, J. Chem. Phys. 107 (1997) 4483; J. Mol. Spectrosc. 278 (2012) 52.

Conformations and Barriers to Methyl Group Internal Rotation in Two Asymmetric Ethers: Propyl Methyl Ether and Butyl Methyl Ether

NASA Astrophysics Data System (ADS)

Long, B. E.; Dechirico, F.; Cooke, S. A.

2012-06-01

The conformational preferences of the O-C-C-C unit are important in many biological systems with the unit generally preferring a gauche configuration compared to an anti configuration. Butyl methyl ether and propyl methyl ether provide very simple systems for this phenomenom to manifest. Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy (CP-FTMW). In the case of butyl methyl ether, only one conformer has been observed. This conformer has torsional angles of COCC = 180°, OCCC = 62° and CCCC = 180° (anti-gauche-anti) and rotational constants of A = 10259.4591(33) MHz, B = 1445.6470(13) MHz, and C = 1356.2944(14) MHz. The rotational spectrum was doubled and has been analyzed to produce an effective barrier to methyl group internal rotation of 780(35) cm-1. A prior rotational spectroscopic study on propyl methyl ether had focused only on the high energy anti-anti conformer. We have analyzed spectra from the lowest energy anti-gauche conformer and the spectroscopic constants will be presented. A summary of the differences in conformational energies and methyl group internal rotation barriers for the class of aliphatic asymmetric ethers will be presented. K. N. Houk, J. E. Eksterowicz, Y.-D. Wu, C. D. Fuglesang, D. B. Mitchell. J. Am. Chem. Soc. 115 (4170), 1993. Hiroshi Kato, Jun Nakagawa, Michiro Hayashi. J. Mol. Spectrosc. 80 (272), 1980.

Isolated Subscapularis Repair in Irreparable Posterosuperior Massive Rotator Cuff Tears Involving the Subscapularis Tendon.

PubMed

Kim, Sung-Jae; Choi, Yun-Rak; Jung, Min; Lee, Won-Yong; Chun, Yong-Min

2017-05-01

No previous study has examined whether isolated subscapularis tendon repair in irreparable posterosuperior massive rotator tears involving the subscapularis tendon in relatively young patients without arthritis can yield satisfactory outcomes. We hypothesized that this procedure would produce favorable outcomes in patients who might otherwise be candidates for reverse arthroplasty. Case series; Level of evidence, 4. This retrospective study included 24 patients in their 50s and 60s, without shoulder arthritis, who underwent arthroscopic isolated subscapularis repair for an irreparable massive rotator cuff tear involving the subscapularis tendon. Preoperative and postoperative visual analog scale (VAS) pain scores, subjective shoulder values (SSVs), University of California at Los Angeles (UCLA) shoulder scores, American Shoulder and Elbow Surgeons (ASES) scores, subscapularis strength (modified bell-press test; maximum of 5), and shoulder active range of motion (ROM) were assessed. Postoperative magnetic resonance arthrography (MRA) was performed 6 months postoperatively to assess structural integrity of the repaired subscapularis. At a mean 34.8 months (range, 24-49 months) of follow-up, VAS pain scores (improved from 7.1 to 2.5), SSVs (33.3 to 75.2), ASES scores (35.9 to 76.0), UCLA shoulder scores (11.6 to 24.8), subscapularis strength, and ROM were significantly improved compared with preoperative measurements ( P < .001). Subscapularis muscle strength improved from 3.7 to 4.2 ( P < .001). For active ROM, forward flexion and internal rotation improved significantly ( P < .001); however, external rotation exhibited no significant improvement. Follow-up MRA was performed in 22 patients (92%) and showed retear of the repaired subscapularis in 6 (27% of the 22). Isolated repair of the subscapularis tendon in irreparable massive rotator cuff tears involving the subscapularis tendon yielded satisfactory short-term outcomes and structural integrity in patients in their 50s and 60s without arthritis. If patients with irreparable massive rotator cuff tears involving the subscapularis tendon are relatively young or have minimal concomitant arthritis, this repair can be worthwhile.

Starspots

NASA Astrophysics Data System (ADS)

Strassmeier, Klaus G.

2009-09-01

Starspots are created by local magnetic fields on the surfaces of stars, just as sunspots. Their fields are strong enough to suppress the overturning convective motion and thus block or redirect the flow of energy from the stellar interior outwards to the surface and consequently appear as locally cool and therefore dark regions against an otherwise bright photosphere (Biermann in Astronomische Nachrichten 264:361, 1938; Z Astrophysik 25:135, 1948). As such, starspots are observable tracers of the yet unknown internal dynamo activity and allow a glimpse into the complex internal stellar magnetic field structure. Starspots also enable the precise measurement of stellar rotation which is among the key ingredients for the expected internal magnetic topology. But whether starspots are just blown-up sunspot analogs, we do not know yet. This article is an attempt to review our current knowledge of starspots. A comparison of a white-light image of the Sun (G2V, 5 Gyr) with a Doppler image of a young solar-like star (EK Draconis; G1.5V, age 100 Myr, rotation 10 × Ω Sun) and with a mean-field dynamo simulation suggests that starspots can be of significantly different appearance and cannot be explained with a scaling of the solar model, even for a star of same mass and effective temperature. Starspots, their surface location and migration pattern, and their link with the stellar dynamo and its internal energy transport, may have far reaching impact also for our understanding of low-mass stellar evolution and formation. Emphasis is given in this review to their importance as activity tracers in particular in the light of more and more precise exoplanet detections around solar-like, and therefore likely spotted, host stars.

Physiological responses to unvarying (steady) and 2-2-1 shifts : Miami International Flight Service Station.

DOT National Transportation Integrated Search

1985-02-01

Two types of shift rotation in the same air traffic facility were investigated in order to determine the relative advantages and disadvantages of nonrotating shift work (steady shift) and rotating shift work. The rotating shift work chosen for compar...

Investigation of MHD instabilities and control in KSTAR preparing for high beta operation

NASA Astrophysics Data System (ADS)

Park, Y. S.; Sabbagh, S. A.; Bialek, J. M.; Berkery, J. W.; Lee, S. G.; Ko, W. H.; Bak, J. G.; Jeon, Y. M.; Park, J. K.; Kim, J.; Hahn, S. H.; Ahn, J.-W.; Yoon, S. W.; Lee, K. D.; Choi, M. J.; Yun, G. S.; Park, H. K.; You, K.-I.; Bae, Y. S.; Oh, Y. K.; Kim, W.-C.; Kwak, J. G.

2013-08-01

Initial H-mode operation of the Korea Superconducting Tokamak Advanced Research (KSTAR) is expanded to higher normalized beta and lower plasma internal inductance moving towards design target operation. As a key supporting device for ITER, an important goal for KSTAR is to produce physics understanding of MHD instabilities at long pulse with steady-state profiles, at high normalized beta, and over a wide range of plasma rotation profiles. An advance from initial plasma operation is a significant increase in plasma stored energy and normalized beta, with Wtot = 340 kJ, βN = 1.9, which is 75% of the level required to reach the computed ideal n = 1 no-wall stability limit. The internal inductance was lowered to 0.9 at sustained H-mode duration up to 5 s. In ohmically heated plasmas, the plasma current reached 1 MA with prolonged pulse length up to 12 s. Rotating MHD modes are observed in the device with perturbations having tearing rather than ideal parity. Modes with m/n = 3/2 are triggered during the H-mode phase but are relatively weak and do not substantially reduce Wtot. In contrast, 2/1 modes to date only appear when the plasma rotation profiles are lowered after H-L back-transition. Subsequent 2/1 mode locking creates a repetitive collapse of βN by more than 50%. Onset behaviour suggests the 3/2 mode is close to being neoclassically unstable. A correlation between the 2/1 mode amplitude and local rotation shear from an x-ray imaging crystal spectrometer suggests that the rotation shear at the mode rational surface is stabilizing. As a method to access the ITER-relevant low plasma rotation regime, plasma rotation alteration by n = 1, 2 applied fields and associated neoclassical toroidal viscosity (NTV) induced torque is presently investigated. The net rotation profile change measured by a charge exchange recombination diagnostic with proper compensation of plasma boundary movement shows initial evidence of non-resonant rotation damping by the n = 1, 2 applied field configurations. The result addresses perspective on access to low rotation regimes for MHD instability studies applicable to ITER. Computation of active RWM control using the VALEN-3D code examines control performance using midplane locked mode detection sensors. The LM sensors are found to be strongly affected by mode and control coil-induced vessel current, and consequently lead to limited control performance theoretically.

Communication: Extended multi-state complete active space second-order perturbation theory: Energy and nuclear gradients

NASA Astrophysics Data System (ADS)

Shiozaki, Toru; Győrffy, Werner; Celani, Paolo; Werner, Hans-Joachim

2011-08-01

The extended multireference quasi-degenerate perturbation theory, proposed by Granovsky [J. Chem. Phys. 134, 214113 (2011)], is combined with internally contracted multi-state complete active space second-order perturbation theory (XMS-CASPT2). The first-order wavefunction is expanded in terms of the union of internally contracted basis functions generated from all the reference functions, which guarantees invariance of the theory with respect to unitary rotations of the reference functions. The method yields improved potentials in the vicinity of avoided crossings and conical intersections. The theory for computing nuclear energy gradients for MS-CASPT2 and XMS-CASPT2 is also presented and the first implementation of these gradient methods is reported. A number of illustrative applications of the new methods are presented.

The effect of in vivo rotator cuff muscle contraction on glenohumeral joint translation: An ultrasonographic and electromyographic study.

PubMed

Rathi, Sangeeta; Taylor, Nicholas F; Green, Rodney A

2016-12-08

The proposed stabilizing mechanism of rotator cuff muscles is to limit excessive humeral head translation. However, an accurate measurement of glenohumeral joint translation in vivo has been challenging. We aimed to measure the effect of rotator cuff muscle contraction on glenohumeral joint translation using real time ultrasound (RTUS) and electromyography. Twenty healthy adults with no history of shoulder pathology were recruited. Six intramuscular electrodes were inserted in the rotator cuff muscles (supraspinatus, upper and lower infraspinatus, teres minor, upper and lower subscapularis). Anterior and posterior glenohumeral translations were measured in testing conditions (with and without translation force, with and without isometric internal and external rotation), in two positions (shoulder neutral, abduction) and views (anterior, posterior). There was reduced glenohumeral translation with rotator cuff muscle contraction in the neutral anterior (F 2,38 =17.8, p<0.01), neutral posterior (F 1.6,31.0 =44.3, p<0.01) and abducted posterior (F 1.5,28.8 =5.2, p<0.02) positions. There were also differences between the amount of translation limited by anterior and posterior rotator cuff muscles in response to anterior and posterior translation forces (p<0.05), indicating that their activity was, to a certain extent, direction specific. For example, in both neutral and abducted positions, contraction of the posterior rotator cuff muscles, infraspinatus and teres minor, appeared to tether anterior translation of the humeral head. Our results confirm that the rotator cuff functions as a stabilizer of the glenohumeral joint by limiting humeral head translation and this is likely to be in a direction-specific manner. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Rotation-Torsion Spectrum of CH_2DOH

NASA Astrophysics Data System (ADS)

Hilali, A. El; Coudert, L. H.; Margulès, L.; Motiyenko, R.; Klee, S.

2010-06-01

Due to the asymmetry of the CH_2D group, the internal rotation problem in the partially deuterated species of methanol CH_2DOH is a complicated one as, unlike in the normal species CH_3OH, the inertia tensor depends on the angle of internal rotation. The CH_2DOH species also displays a dense far infrared torsional spectrum difficult to assign. Recently 38 torsional subbands of CH_2DOH have been identified, but for most of them there is neither an assignment nor an analysis of their rotational structure. In this paper an analysis of the rotation-torsion spectrum of CH_2DOH will be presented. The rotational structure of 23 torsional subbands have been assigned. These subbands are Δ v_t &ge 1 perpendicular subbands with a value of v'_t up to 10b and values of K' and K'' ranging from 0 to 9. For all subbands, the Q-branch was assigned, for 3 subbands, the R- and P-branches could also be found. The results of the rotational analysis with an expansion in J(J+1) of the new subbands and of already observed ones will be presented. When available, microwave lines within the lower torsional level, recorded in this work or already measured, were added to the data set. A theoretical approach aimed at calculating the rotation-torsion energy levels has also been developed. It is based on an expansion in terms of rotation-torsion operators with C_s symmetry and accounts for the dependence of the inertia tensor on the angle of internal rotation. This approach will be used to carry out a preliminary global analyses of the wavenumbers and of the frequencies. Lauvergnat, Coudert, Klee, and Smirnov, J. Mol. Spec. 256 (2009) 204. Quade, Liu, Mukhopadhyay, and Su, J. Mol. Spec. 192 (1998) 378; Mukhopadhyay, J. Mol. Struct. 695-696 (2004) 357. Liu and Quade, J. Mol. Spec. 146 (1991) 252 Mukhopadhyay et al., J. Chem. Phys. 116 (2002) 3710.

Effect of ACL Transection on Internal Tibial Rotation in an in Vitro Simulated Pivot Landing

PubMed Central

Oh, Youkeun K.; Kreinbrink, Jennifer L.; Ashton-Miller, James A.; Wojtys, Edward M.

2011-01-01

Background: The amount of resistance provided by the ACL (anterior cruciate ligament) to axial tibial rotation remains controversial. The goal of this study was to test the primary hypotheses that ACL transection would not significantly affect tibial rotation under the large impulsive loads associated with a simulated pivot landing but would increase anterior tibial translation. Methods: Twelve cadaveric knees (mean age of donors [and standard deviation] at the time of death, 65.0 ± 10.5 years) were mounted in a custom testing apparatus to simulate a single-leg pivot landing. A compound impulsive load was applied to the distal part of the tibia with compression (∼800 N), flexion moment (∼40 N-m), and axial tibial torque (∼17 N-m) in the presence of five trans-knee muscle forces. A differential variable reluctance transducer mounted on the anteromedial aspect of the ACL measured relative strain. With the knee initially in 15° of flexion, and after five combined compression and flexion moment (baseline) loading trials, six trials were conducted with the addition of either internal or external tibial torque (internal or external loading), and then six baseline trials were performed. The ACL was then sectioned, six baseline trials were repeated, and then six trials of either the internal or the external loading condition, whichever had initially resulted in the larger relative ACL strain, were carried out. Tibiofemoral kinematics were measured optoelectronically. The results were analyzed with a nonparametric Wilcoxon signed-rank test. Results: Following ACL transection, the increase in the normalized internal tibial rotation was significant but small (0.7°/N-m ± 0.3°/N-m to 0.8°/N-m ± 0.3°/N-m, p = 0.012), while anterior tibial translation increased significantly (3.8 ± 2.9 to 7.0 ± 2.9 mm, p = 0.017). Conclusions: ACL transection leads to a small increase in internal tibial rotation, equivalent to a 13% decrease in the dynamic rotational resistance, under the large forces associated with a simulated pivot landing, but it leads to a significant increase in anterior tibial translation. Clinical Relevance: An ACL reconstruction that restores both ligament orientation and stiffness will provide major resistance to anterior tibial translation while providing minor resistance to axial tibial rotation. PMID:21325589

Comparison of fit accuracy and torque maintenance of zirconia and titanium abutments for internal tri-channel and external-hex implant connections.

PubMed

Siadat, Hakimeh; Beyabanaki, Elaheh; Mousavi, Niloufar; Alikhasi, Marzieh

2017-08-01

This in vitro study aimed to evaluate the effect of implant connection design (external vs. internal) on the fit discrepancy and torque loss of zirconia and titanium abutments. Two regular platform dental implants, one with external connection (Brånemark, Nobel Biocare AB) and the other with internal connection (Noble Replace, Nobel Biocare AB), were selected. Seven titanium and seven customized zirconia abutments were used for each connection design. Measurements of geometry, marginal discrepancy, and rotational freedom were done using video measuring machine. To measure the torque loss, each abutment was torqued to 35 Ncm and then opened by means of a digital torque wrench. Data were analyzed with two-way ANOVA and t-test at α=0.05 of significance. There were significant differences in the geometrical measurements and rotational freedom between abutments of two connection groups ( P <.001). Also, the results showed significant differences between titanium abutments of internal and external connection implants in terms of rotational freedom ( P <.001). Not only customized internal abutments but also customized external abutments did not have the exact geometry of prefabricated abutments ( P <.001). However, neither connection type ( P =.15) nor abutment material ( P =.38) affected torque loss. Abutments with internal connection showed less rotational freedom. However, better marginal fit was observed in externally connected abutments. Also, customized abutments with either connection could not duplicate the exact geometry of their corresponding prefabricated abutment. However, neither abutment connection nor material affected torque loss values.

Influence of ankle joint plantarflexion and dorsiflexion on lateral ankle sprain: A computational study.

PubMed

Purevsuren, Tserenchimed; Kim, Kyungsoo; Batbaatar, Myagmarbayar; Lee, SuKyoung; Kim, Yoon Hyuk

2018-05-01

Understanding the mechanism of injury involved in lateral ankle sprain is essential to prevent injury, to establish surgical repair and reconstruction, and to plan reliable rehabilitation protocols. Most studies for lateral ankle sprain posit that ankle inversion, internal rotation, and plantarflexion are involved in the mechanism of injury. However, recent studies indicated that ankle dorsiflexion also plays an important role in the lateral ankle sprain mechanism. In this study, the contributions of ankle plantarflexion and dorsiflexion on the ankle joint were evaluated under complex combinations of internal and inversion moments. A multibody ankle joint model including 24 ligaments was developed and validated against two experimental cadaveric studies. The effects of ankle plantarflexion (up to 60°) and dorsiflexion (up to 30°) on the lateral ankle sprain mechanism under ankle inversion moment coupled with internal rotational moment were investigated using the validated model. Lateral ankle sprain injuries can occur during ankle dorsiflexion, in which the calcaneofibular ligament and anterior talofibular ligament tears may occur associated with excessive inversion and internal rotational moment, respectively. Various combinations of inversion and internal moment may lead to anterior talofibular ligament injuries at early ankle plantarflexion, while the inversion moment acts as a primary factor to tear the anterior talofibular ligament in early plantarflexion. It is better to consider inversion and internal rotation as primary factors of the lateral ankle sprain mechanism, while plantarflexion or dorsiflexion can be secondary factor. This information will help to clarify the lateral ankle sprain mechanism of injury.

Inter-rater Reliability of Sustained Aberrant Movement Patterns as a Clinical Assessment of Muscular Fatigue

PubMed Central

Aerts, Frank; Carrier, Kathy; Alwood, Becky

2016-01-01

Background: The assessment of clinical manifestation of muscle fatigue is an effective procedure in establishing therapeutic exercise dose. Few studies have evaluated physical therapist reliability in establishing muscle fatigue through detection of changes in quality of movement patterns in a live setting. Objective: The purpose of this study is to evaluate the inter-rater reliability of physical therapists’ ability to detect altered movement patterns due to muscle fatigue. Design: A reliability study in a live setting with multiple raters. Participants: Forty-four healthy individuals (ages 19-35) were evaluated by six physical therapists in a live setting. Methods: Participants were evaluated by physical therapists for altered movement patterns during resisted shoulder rotation. Each participant completed a total of four tests: right shoulder internal rotation, right shoulder external rotation, left shoulder internal rotation and left shoulder external rotation. Results: For all tests combined, the inter-rater reliability for a single rater scoring ICC (2,1) was .65 (95%, .60, .71) This corresponds to moderate inter-rater reliability between physical therapists. Limitations: The results of this study apply only to healthy participants and therefore cannot be generalized to a symptomatic population. Conclusion: Moderate inter-rater reliability was found between physical therapists in establishing muscle fatigue through the observation of sustained altered movement patterns during dynamic resistive shoulder internal and external rotation. PMID:27347241

Use of the Spencer Technique on Collegiate Baseball Players: Effect on Physical Performance and Self-Report Measures.

PubMed

Curcio, Janine E; Grana, Matthew J; England, Stacey; Banyas, Paige M; Palmer, Benjamin D; Placke, Arielle E; Rieck, William A; Eade, Amber M

2017-03-01

Repeated overhead throwing in baseball players alters range of motion (ROM), contributing to shoulder injury. The Spencer technique has been used, anecdotally, to reduce the effects of throwing-induced limitations in ROM. To quantify the effects of a single administration of the Spencer technique on the ROM and performance of collegiate baseball pitchers. Pitchers from the Seton Hill University men's baseball team were randomly assigned to 2 treatment groups: Spencer technique or sham therapy. The first week consisted of baseline outcome measurements (1 week before treatment), including ROM (flexion, extension, abduction, adduction, internal rotation, and external rotation) of the dominant throwing arm, 10 maximum velocity throws, and self-reported performance using the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow Score (KJOC-SES). The second week consisted of pretreatment ROM measurement, followed by a single treatment and repeated measurement of all outcomes. Of 16 players, 15 met inclusion criteria. An effect of training on ROM between weeks 1 and 2 for all players consisted of significantly decreased internal rotation (P=.02) and increased external rotation (P=.04). A differential effect of treatment was found on the mean difference in internal rotation after treatment, compared with the mean difference before treatment on the same day (P=.01). Additionally, a trend toward statistical significance for abduction (P=.08) was noted. Analyses reveal that these effects were caused by significant increases in the internal rotation and abduction for the Spencer group only (P=.02). All other analyses of ROM, as well as performance measured by maximum velocity throws and the KJOC-SES, revealed no differential effect of treatment. The results of this study support the use of the Spencer technique in counteracting the potentially negative effects of repeated throwing on internal rotation. However, a single administration did not affect functional ability in this study. Future studies of longer duration and including differing levels of play, injury status, and playing position will be needed to further evaluate the full potential of the Spencer technique in athletes who engage in repeated overhead arm movements.

Test-retest reliability of cardinal plane isokinetic hip torque and EMG.

PubMed

Claiborne, Tina L; Timmons, Mark K; Pincivero, Danny M

2009-10-01

The objective of the present study was to establish test-retest reliability of isokinetic hip torque and prime mover electromyogram (EMG) through the three cardinal planes of motion. Thirteen healthy young adults participated in two experimental sessions, separated by approximately one week. During each session, isokinetic hip torque was evaluated on the Biodex Isokinetic Dynamometer at a velocity of 60 deg/s. Subjects performed three maximal-effort concentric and eccentric contractions, separately, for right and left hip abduction/adduction, flexion/extension, and internal/external rotation. Surface EMGs were sampled from the gluteus maximus, gluteus medius, adductor, medial and lateral hamstring, and rectus femoris muscles during all contractions. Intraclass correlation coefficients (ICC - 2,1) and standard errors of measurement (SEM) were calculated for peak torque for each movement direction and contraction mode, while ICCs were only computed for the EMG data. Motions that demonstrated high torque reliability included concentric hip abduction (right and left), flexion (right and left), extension (right) and internal rotation (right and left), and eccentric hip abduction (left), adduction (left), flexion (right), and extension (right and left) (ICC range=0.81-0.91). Motions with moderate torque reliability included concentric hip adduction (right), extension (left), internal rotation (left), and external rotation (right), and eccentric hip abduction and adduction (right), flexion (left), internal rotation (right and left), and external rotation (right and left) (ICC range=0.49-0.79). The majority of the EMG sampled muscles (n=12 and n=11 for concentric and eccentric contractions, respectively) demonstrated high reliability (ICC=0.81-0.95). Instances of low, or unacceptable, EMG reliability values occurred for the medial hamstring muscle of the left leg (both contraction modes) and the adductor muscle of the right leg during eccentric internal rotation. The major finding revealed high and moderate levels of between-day reliability of isokinetic hip peak torque and prime mover EMG. It is recommended that the day-to-day variability estimates concomitant with acceptable levels of reliability be considered when attempting to objectify intervention effects on hip muscle performance.

Consolidated Academic and Research Exposition: A Pilot Study of an Innovative Education Method to Increase Residents' Research Involvement

PubMed Central

Basu Ray, Indranill; Henry, Tracey L.; Davis, William; Alam, Jawed; Amedee, Ronald G.; Pinsky, William W.

2012-01-01

Background Internal medicine residents at the Ochsner Clinic Foundation stay engaged with clinical work and have difficulty initiating and completing research and publishing their scholarly activities. Commonly cited barriers include lack of knowledge about institutional research programs, lack of confidence regarding medical writing skills, lack of time, and failure to understand the value of research. The residency directors at Ochsner initiated the Consolidated Academic and Research Exposition (CARE) program to teach basic research skills and encourage residents' interest and productivity in research. Methods The CARE program includes 4 core components: house staff mentoring and the Resident Career Development Program, a journal club, medical writing instruction, and research engagement. Particular emphasis is given to projects that could be completed within a 1-month period and result in publication, enabling residents to use a 1-month elective rotation during their first postgraduate year. The sessions are mandatory for residents, except for those on specified rotations, including the critical care service and the night float rotation and those who are postcall. Results In 2010-2011, 6 residents submitted abstracts to the Louisiana Chapter of the American College of Physicians Associates meeting; 2 abstracts were accepted for presentation. In 2011-2012, there were 14 submissions, 4 of which were accepted for presentation. In 2010-2011, there were 4 submissions to the Southern Hospitalist Conference, which increased to 7 submissions in 2011-2012. The second best presentation award at the Southern Hospitalist Conference was also earned by a resident of this institution. The program saw a 110% total increase in scholarly activity from 2010-2011 to 2011-2012. Discussion The CARE program has been in existence for approximately 1 year. Preliminary results were tabulated based on research proposals, posters, abstracts, case reports, and presentations submitted and/or accepted at leading medical conferences over the past year as compared to the same period 1 year ago. Residents, based on the Accreditation Council for Graduate Medical Education Resident Survey responses, were more satisfied with the opportunities provided to them to participate in research or scholarly activities. Our preliminary results suggest that an organized, structured research curriculum in internal medicine residency programs is critical to promoting, initiating, and completing scholarly activity during a residency program. Conclusion Ochsner's CARE program has appreciably enhanced internal medicine residents' interest in research-related activity, resulting in a significant increase in resident-authored research papers, abstracts, posters, and case reports being accepted at leading national medical conferences. PMID:23267266

Exercise therapy for treatment of supraspinatus tears does not alter glenohumeral kinematics during internal/external rotation with the arm at the side.

PubMed

Ferrer, Gerald A; Miller, R Matthew; Zlotnicki, Jason P; Tashman, Scott; Irrgang, James J; Musahl, Volker; Debski, Richard E

2018-01-01

Rotator cuff tears are a significant clinical problem, with exercise therapy being a common treatment option for patients. Failure rates of exercise therapy may be due to the failure to improve glenohumeral kinematics. Tears involving the supraspinatus may result in altered glenohumeral kinematics and joint instability for internal/external rotation with the arm at the side because not all muscles used to stabilize the glenohumeral joint are functioning normally. The objective of the study is to assess in vivo glenohumeral kinematic changes for internal/external rotation motions with the arm at the side of patients with a symptomatic full-thickness supraspinatus tear before and after a 12-week exercise therapy programme. Five patients underwent dynamic stereoradiography analysis before and after a 12-week exercise therapy protocol to measure changes in glenohumeral kinematics during transverse plane internal/external rotation with the arm at the side. Patient-reported outcomes and shoulder strength were also evaluated. No patient sought surgery immediately following exercise therapy. Significant improvements in isometric shoulder strength and patient-reported outcomes were observed (p < 0.05). No significant changes in glenohumeral kinematics following physical therapy were found. Isolated supraspinatus tears resulted in increased joint translations compared to healthy controls from the previous literature for internal/external rotation with the arm at the side. Despite satisfactory clinical outcomes following exercise therapy, glenohumeral kinematics did not change. The lack of changes may be due to the motion studied or the focus of current exercise therapy protocols being increasing shoulder strength and restoring range of motion. Current exercise therapy protocols should be adapted to also focus on restoring glenohumeral kinematics to improve joint stability since exercise therapy may have different effects depending on the motions of daily living. Prognostic study, Level II.

Contribution of the Pubofemoral Ligament to Hip Stability: A Biomechanical Study.

PubMed

Martin, Hal D; Khoury, Anthony N; Schröder, Ricardo; Johnson, Eric; Gómez-Hoyos, Juan; Campos, Salvador; Palmer, Ian J

2017-02-01

To determine the isolated function of the pubofemoral ligament of the hip capsule and its contribution to hip stability in external/internal rotational motion during flexion greater than 30° and abduction. Thirteen hips from 7 fresh-frozen pelvis-to-toe cadavers were skeletonized from the lumbar spine to the distal femur with the capsular ligaments intact. Computed tomographic imaging was performed to ensure no occult pathological state existed, and assess bony anatomy. Specimens were placed on a surgical table in supine position with lower extremities resting on a custom-designed polyvinylchloride frame. Hip internal and external rotation was measured with the hip placed into a combination of the following motions: 30°, 60°, 110° hip flexion and 0°, 20°, 40° abduction. Testing positions were randomized. The pubofemoral ligament was released and measurements were repeated, followed by releasing the ligamentum teres. Analysis of the 2,106 measurements recorded demonstrates the pubofemoral ligament as a main controller of hip internal rotation during hip flexion beyond 30° and abduction. Hip internal rotation was increased up to 438.9% (P < .001) when the pubofemoral ligament was released and 412.9% (P < .001) when both the pubofemoral and teres ligament were released, compared with the native state. The hypothesis of the pubofemoral ligament as one of the contributing factors of anterior inferior hip stability by controlling external rotation of the hip in flexion beyond 30° and abduction was disproved. The pubofemoral ligament maintains a key function in limiting internal rotation in the position of increasing hip flexion beyond 30° and abduction. This cadaveric study concludes previous attempts at understanding the anatomical and biomechanical function of the capsular ligaments and their role in hip stability. The present study contributes to the understanding of hip stability and biomechanical function of the pubofemoral ligament. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Relationship between gluteal muscle activation and upper extremity kinematics and kinetics in softball position players.

PubMed

Oliver, Gretchen D

2014-03-01

As the biomechanical literature concerning softball pitching is evolving, there are no data to support the mechanics of softball position players. Pitching literature supports the whole kinetic chain approach including the lower extremity in proper throwing mechanics. The purpose of this project was to examine the gluteal muscle group activation patterns and their relationship with shoulder and elbow kinematics and kinetics during the overhead throwing motion of softball position players. Eighteen Division I National Collegiate Athletic Association softball players (19.2 ± 1.0 years; 68.9 ± 8.7 kg; 168.6 ± 6.6 cm) who were listed on the active playing roster volunteered. Electromyographic, kinematic, and kinetic data were collected while players caught a simulated hit or pitched ball and perform their position throw. Pearson correlation revealed a significant negative correlation between non-throwing gluteus maximus during the phase of maximum external rotation to maximum internal rotation (MIR) and elbow moments at ball release (r = -0.52). While at ball release, trunk flexion and rotation both had a positive relationship with shoulder moments at MIR (r = 0.69, r = 0.82, respectively) suggesting that the kinematic actions of the pelvis and trunk are strongly related to the actions of the shoulder during throwing.

Operation in low edge safety factor regime and passive disruption avoidance due to stellarator rotational transform in the Compact Toroidal Hybrid

NASA Astrophysics Data System (ADS)

Pandya, M. D.; Ennis, D. A.; Hartwell, G. J.; Maurer, D. A.

2015-11-01

Low edge safety factor operation at a value less than two (q (a) = 1 /ttot (a) < 2) is routine on the Compact Toroidal Hybrid device. Presently, the operational space of this current carrying stellarator extends down to q (a) = 1 . 2 without significant n = 1 kink mode activity after the initial plasma current rise of the discharge. The disruption dynamics of these low q (a) plasmas depend upon the fraction of rotational transform produced by external stellarator coils to that generated by the plasma current. We observe that when about 10% of the total rotational transform is supplied by the stellarator coils, low q (a) disruptions are passively suppressed and avoided even though q (a) < 2 . When the plasma does disrupt, the instability precursors measured and implicated as the cause are internal tearing modes with poloidal, m, and toroidal, n, mode numbers of m / n = 3 / 2 and 4 / 3 observed by external magnetic sensors, and m / n = 1 / 1 activity observed by core soft x-ray emissivity measurements. Even though q (a) passes through and becomes much less than two, external n = 1 kink mode activity does not appear to play a significant role in the observed disruption phenomenology. This work is supported by US Department of Energy Grant No. DE-FG02-00ER54610.

Position of Immobilization After First-Time Traumatic Anterior Glenohumeral Dislocation: A Literature Review

PubMed Central

Gutkowska, Olga; Martynkiewicz, Jacek; Gosk, Jerzy

2017-01-01

Anterior glenohumeral dislocation affects about 2% of the general population during the lifetime. The incidence of traumatic glenohumeral dislocation ranges from 8.2 to 26.69 per 100 000 population per year. The most common complication is recurrent dislocation occurring in 17–96% of the patients. The majority of patients are treated conservatively by closed reduction and immobilization in internal rotation for 2–3 weeks. However, no clear conservative treatment protocol exists. Immobilization in external rotation can be considered an alternative. A range of external rotation braces are commercially available. The purpose of this work was to review the current literature on conservative management of glenohumeral dislocation and to compare the results of immobilization in internal and external rotation. A comprehensive literature search and review was performed using the keywords “glenohumeral dislocation”, “shoulder dislocation”, “immobilization”, “external rotation”, and “recurrent dislocation” in PubMed, MEDLINE, Cochrane Library, Scopus, and Google Scholar databases from their inceptions to May 2016. Three cadaveric studies, 6 imaging studies, 10 clinical studies, and 4 meta-analyses were identified. The total number of 734 patients were included in the clinical studies. Literature analysis revealed better coaptation of the labrum on the glenoid rim in external rotation in cadaveric and imaging studies. However, this tendency was not confirmed by lower redislocation rates or better quality of life in clinical studies. On the basis of the available literature, we cannot confirm the superiority of immobilization in external rotation after glenohumeral dislocation when compared to internal rotation. A yet-to-be-determined group of patients with specific labroligamentous injury pattern may benefit from immobilization in external rotation. Further studies are needed to identify these patients. PMID:28710344

Optimized functional femoral rotation in navigated total knee arthroplasty considering ligament tension.

PubMed

Walde, T A; Bussert, J; Sehmisch, S; Balcarek, P; Stürmer, K M; Walde, H J; Frosch, K H

2010-12-01

Femoral malrotation in total knee arthroplasty is correlated to an increased number of revisions. Anatomic landmarks such as Whiteside line, posterior condyle axis and transepicondylar axis are used for determining femoral component rotation. The femoral rotation achieved with the anatomical landmarks is compared to the femoral rotation achieved by a navigated ligament tension-based tibia-first technique. Ninety-three consecutive patients with gonarthritis were prospectively enrolled. Intraoperatively the anatomical landmarks for femoral rotation and the achieved femoral rotation using a navigated tension-based tibia-first technique were determined and stored for further comparison. A pre- and postoperative functional diagram displaying the extension and flexion and varus or valgus positions was also part of the evaluation. Using anatomical landmarks the rotational errors ranged from 12.2° of internal rotation to 15.5° of external rotation from parallel to the tibial resection surface at 90° flexion. A statistical significant improved femoral rotation was achieved using the ligament tension-based method with a rotational error ranged from 3.0° of internal rotation to 2.4° of external rotation. The functional analyses demonstrated statistical significant lower varus/valgus deviations within the flexion range and an improved maximum varus deviation at 90° flexion using the ligament tension-based method. Compared to the anatomical landmarks a balanced, almost parallel flexion gap was achieved using a navigation technique taking the ligament tension of the knee joint into account. As a result the improved femoral rotation was demonstrated by the functional evaluation. Unilateral overloading of the polyethylene inlay and unilateral instability can thus be avoided. Copyright © 2009 Elsevier B.V. All rights reserved.

QUAGMIRE v1.3: a quasi-geostrophic model for investigating rotating fluids experiments

NASA Astrophysics Data System (ADS)

Williams, P. D.; Haine, T. W. N.; Read, P. L.; Lewis, S. R.; Yamazaki, Y. H.

2008-09-01

QUAGMIRE is a quasi-geostrophic numerical model for performing fast, high-resolution simulations of multi-layer rotating annulus laboratory experiments on a desktop personal computer. The model uses a hybrid finite-difference/spectral approach to numerically integrate the coupled nonlinear partial differential equations of motion in cylindrical geometry in each layer. Version 1.3 implements the special case of two fluid layers of equal resting depths. The flow is forced either by a differentially rotating lid, or by relaxation to specified streamfunction or potential vorticity fields, or both. Dissipation is achieved through Ekman layer pumping and suction at the horizontal boundaries, including the internal interface. The effects of weak interfacial tension are included, as well as the linear topographic beta-effect and the quadratic centripetal beta-effect. Stochastic forcing may optionally be activated, to represent approximately the effects of random unresolved features. A leapfrog time stepping scheme is used, with a Robert filter. Flows simulated by the model agree well with those observed in the corresponding laboratory experiments.

QUAGMIRE v1.3: a quasi-geostrophic model for investigating rotating fluids experiments

NASA Astrophysics Data System (ADS)

Williams, P. D.; Haine, T. W. N.; Read, P. L.; Lewis, S. R.; Yamazaki, Y. H.

2009-02-01

QUAGMIRE is a quasi-geostrophic numerical model for performing fast, high-resolution simulations of multi-layer rotating annulus laboratory experiments on a desktop personal computer. The model uses a hybrid finite-difference/spectral approach to numerically integrate the coupled nonlinear partial differential equations of motion in cylindrical geometry in each layer. Version 1.3 implements the special case of two fluid layers of equal resting depths. The flow is forced either by a differentially rotating lid, or by relaxation to specified streamfunction or potential vorticity fields, or both. Dissipation is achieved through Ekman layer pumping and suction at the horizontal boundaries, including the internal interface. The effects of weak interfacial tension are included, as well as the linear topographic beta-effect and the quadratic centripetal beta-effect. Stochastic forcing may optionally be activated, to represent approximately the effects of random unresolved features. A leapfrog time stepping scheme is used, with a Robert filter. Flows simulated by the model agree well with those observed in the corresponding laboratory experiments.

Prevention of shoulder injuries in overhead athletes: a science-based approach

PubMed Central

Cools, Ann M.; Johansson, Fredrik R.; Borms, Dorien; Maenhout, Annelies

2015-01-01

The shoulder is at high risk for injury during overhead sports, in particular in throwing or hitting activities, such as baseball, tennis, handball, and volleyball. In order to create a scientific basis for the prevention of recurrent injuries in overhead athletes, four steps need to be undertaken: (1) risk factors for injury and re-injury need to be defined; (2) established risk factors may be used as return-to-play criteria, with cut-off values based on normative databases; (3) these variables need to be measured using reliable, valid assessment tools and procedures; and (4) preventative training programs need to be designed and implemented into the training program of the athlete in order to prevent re-injury. In general, three risk factors have been defined that may form the basis for recommendations for the prevention of recurrent injury and return to play after injury: glenohumeral internal-rotation deficit (GIRD); rotator cuff strength, in particular the strength of the external rotators; and scapular dyskinesis, in particular scapular position and strength. PMID:26537804

Difficulties in Laboratory Studies and Astronomical Observations of Organic Molecules: Hydroxyacetone and Lactic Acid

NASA Technical Reports Server (NTRS)

Apponi, A. J.; Brewster, M. A.; Hoy, J.; Ziurys, L. M.

2006-01-01

For the past 35 years, radio astronomy has revealed a rich organic chemistry in the interstellar gas, which is exceptionally complex towards active star-forming regions. New solar systems condense out of this gas and may influence the evolution of life on newly formed planets. Much of the biologically important functionality is present among the some 130 gas-phase molecules found to date, including alcohols, aldehydes, ketones, acids, amines, amides and even the simplest sugar - glycolaldehyde. Still, many unidentified interstellar radio signals remain, and their identification relies on further laboratory study. The molecules hydroxyacetone and lactic acid are relatively small organic molecules, but possess rather complex rotational spectra owing to their high asymmetry. Hydroxyacetone is particularly problematic because it possess a very low barrier to internal rotation, and exhibits strong coupling of the free-rotor states with the overall rotation of the molecule. As in the case of acetamide, a full decomposition method was employed to order the resultant eigenstates onto normal asymmetric top eigenvectors.

Activity-rotation relations for lower main sequence stars

NASA Astrophysics Data System (ADS)

Dobson-Hockey, Andrea Kay

It was known for some time that stellar rotation and activity are related, both for chromospheric activity and control activity. Younger, more rapidly rotating stars of a given spectral type generally show higher levels of activity than do older, more slowly rotating stars. On the Sun acitivity is distinctly related to magnetic fields. This leads to the suggestion that activity, at least in solar-type stars, is traceable to a magnetic dynamo which results from the interaction of rotation and differential rotation with convection. The more efficient the coriolis forces are at introducing helicity into convective motions, the more the magnetic field will be amplified and the more activity that is expected. The precise nature of the relationship between magnetic fields, rotation, and activity remains to be well-defined. It is the purpose to examine the relationship between activity and rotation in order to better define and express such a relation (or relations). To meet this goal, a comprehensive sample of stars was collected from the published literature having two or more of the following: chromospheric Ca II, H, and K emission indices; coronal soft X-ray illumination; rotation rates; and where possible, ages. It is seen that the use of normalized activity units and Rossby number generally improves the correlation between activity and rotation. The use of the convective turnover time further permits a possible explanation for the distribution of stars in an activity-color diagram. A large and homogeneous data set permits better definition of previously examined functional dependencies such as the time decay of activity and the relationship between chromospheric and coronal activity indicators.

Spatio-temporal brain activity related to rotation method during a mental rotation task of three-dimensional objects: an MEG study.

PubMed

Kawamichi, Hiroaki; Kikuchi, Yoshiaki; Ueno, Shoogo

2007-09-01

During mental rotation tasks, subjects perform mental simulation to solve tasks. However, detailed neural mechanisms underlying mental rotation of three-dimensional (3D) objects, particularly, whether higher motor areas related to mental simulation are activated, remain unknown. We hypothesized that environmental monitoring-a process based on environmental information and is included in motor execution-is as a key factor affecting the utilization of higher motor areas. Therefore, using magnetoencephalography (MEG), we measured spatio-temporal brain activities during two types (two-dimensional (2D) and 3D rotation tasks) of mental rotation of 3D objects. Only the 3D rotation tasks required subjects to mentally rotate objects in a depth plane with visualization of hidden parts of the visual stimuli by acquiring and retrieving 3D information. In cases showing significant differences in the averaged activities at 100-ms intervals between the two rotations, the activities were located in the right dorsal premotor (PMd) at approximately 500 ms. In these cases, averaged activities during 3D rotation were greater than those during 2D rotation, implying that the right PMd activities are related to environmental monitoring. During 3D rotation, higher activities were observed from 200 to 300 ms in the left PMd and from 400 to 700 ms in the right PMd. It is considered that the left PMd is related to primary motor control, whereas the right PMd plays a supplementary role during mental simulation. Further, during 3D rotation, late higher activities related to mental simulation are observed in the right superior parietal lobule (SPL), which is connected to PMd.

Microwave Spectroscopy of 2-PENTANONE

NASA Astrophysics Data System (ADS)

Andresen, Maike; Nguyen, Ha Vinh Lam; Kleiner, Isabelle; Stahl, Wolfgang

2017-06-01

Methyl propyl ketone (MPK) or 2-Pentanone is known to be an alarm pheroromone released by the mandibular glands of the bees. It is a highly volatile compound. This molecule was studied by a combination of quantum chemical calculations and microwave spectroscopy in order to get informations about the lowest energy conformers and their structures.The rotational spectrum of 2-pentanone was measured using the molecular beam Fourier transform microwave spectrometer in Aachen operating between 2 and 26.5 GHz. Ab initio calculations determine 4 conformers but only two of them are observed in our jet-beam conditions.The lowest conformer has a C_{1} structure and its spectrum shows internal rotation splittings arising from two methyl groups. The internal splittings of 305 transitions for this conformer were analyzed using the XIAM code It led to the determination of the values for the barrier heights hindering the internal rotation of two methyl groups of 239 cm^{-1} and 980 cm^{-1} respectively. The next energy conformer has a C_{s} structure and the analysis of the internal splittings of 134 transitions using the XIAM code and the BELGI code led to the determination of internal rotation barrier height of 186 cm^{-1}. Comparisons of quantum chemistry and experimental results will be discussed. H. Hartwig, H. Dreizler, Z. Naturforsch. 51a, 923 (1996). J. T. Hougen, I. Kleiner and M. Godefroid, J. Mol. Spectrosc., 163, 559-586 (1994).

Evaluation of Hip Internal and External Rotation Range of Motion as an Injury Risk Factor for Hip, Abdominal and Groin Injuries in Professional Baseball Players

PubMed Central

Ma, Richard; Zhou, Hanbing; Thompson, Matthew; Dawson, Courtney; Nguyen, Joseph; Coleman, Struan

2015-01-01

Normal hip range of motion (ROM) is essential in running and transfer of energy from lower to upper extremities during overhead throwing. Dysfunctional hip ROM may alter lower extremity kinematics and predispose athletes to hip and groin injuries. The purpose of this study is characterize hip internal/external ROM (Arc) and its effect on the risk of hip, hamstring, and groin injuries in professional baseball players. Bilateral hip internal and external ROM was measured on all baseball players (N=201) in one professional organization (major and minor league) during spring training. Players were organized according to their respective positions. All injuries were documented prospectively for an entire MLB season (2010 to 2011). Data was analyzed according to position and injuries during the season. Total number of players (N=201) with an average age of 24±3.6 (range=17-37). Both pitchers (N=93) and catchers (N=22) had significantly decreased mean hip internal rotation and overall hip arc of motion compared to the positional players (N=86). Players with hip, groin, and hamstring injury also had decreased hip rotation arc when compared to the normal group. Overall, there is a correlation between decreased hip internal rotation and total arc of motion with hip, hamstring, and groin injuries. PMID:26793294

Biofuels, bioenergy, and bioproducts from sustainable agricultural and forest crops: proceedings of the short rotation crops international conference

Treesearch

Ronald S., Jr. Zalesny; Rob Mitchell; Jim, eds. Richardson

2008-01-01

The goal of this conference was to initiate and provide opportunities for an international forum on the science and application of producing both agricultural and forest crops for biofuels, bioenergy, and bioproducts. There is a substantial global need for development of such systems and technologies that can economically and sustainably produce short rotation crops...

The Sub-bureau for Atmospheric Angular Momentum of the International Earth Rotation Service - A meteorological data center with geodetic applications

NASA Technical Reports Server (NTRS)

Salstein, David A.; Kann, Deirdre M.; Miller, Alvin J.; Rosen, Richard D.

1993-01-01

By exchanging angular momentum with the solid portion of the earth, the atmosphere plays a vital role in exciting small but measurable changes in the rotation of our planet. Recognizing this relationship, the International Earth Rotation Service invited the U.S. National Meteorological Center to organize a Sub-bureau for Atmospheric Angular Momentum (SBAAM) for the purpose of collecting, distributing, archiving, and analyzing atmospheric parameters relevant to earth rotation/polar motion. These functions of wind and surface pressure are being computed with data from several of the world's weather services, and they are being widely applied to the research and operations of the geodetic community. The SBAAM began operating formally in October 1989, and this article highlights its development, operations, and significance.

Shoulder tenotomies to improve passive motion and relieve pain in patients with spastic hemiplegia after upper motor neuron injury.

PubMed

Namdari, Surena; Alosh, Hassan; Baldwin, Keith; Mehta, Samir; Keenan, Mary Ann

2011-07-01

Shoulder adduction and internal rotation contractures commonly develop in patients with spastic hemiplegia after upper motor neuron (UMN) injury. Contractures are often painful, macerate skin, and impair axillary hygiene. We hypothesize that shoulder tenotomies are an effective means of pain relief and passive motion restoration in patients without active upper extremity motor function. A consecutive series of 36 adults (10 men, 26 women) with spastic hemiplegia from UMN injury, shoulder adduction, and internal rotation contractures, and no active movement, who underwent shoulder tenotomies of the pectoralis major, latissimus dorsi, teres major, and subscapularis were evaluated. Patients were an average age of 52.2 years. Pain, passive motion, and satisfaction were considered preoperatively and postoperatively. Average follow-up was 14.3 months. Preoperatively, all patients had limited passive motion that interfered with passive functions. Nineteen patients had pain. After surgery, passive extension, flexion, abduction, and external rotation improved from 50%, 27%, 27%, and 1% to 85%, 70%, 66%, and 56%, respectively, compared with the normal contralateral side (P < .001). All patients with preoperative pain had improved pain relief at follow-up, with 18 (95%) being pain-free. Thirty-five (97%) were satisfied with the outcome of surgery, and all patients reported improved axillary hygiene and skin care. Age, gender, etiology, and chronicity of UMN injury were not associated with improvement in motion. We observed improvements in passive ROM and high patient satisfaction with surgery at early follow-up. Patients who had pain with passive motion preoperatively had significant improvements in pain after shoulder tenotomy. Shoulder tenotomy to relieve spastic contractures resulting from UMN injury can be an effective means of pain relief and improved passive range of motion in patients without active motor function. Copyright © 2011 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

A multicenter study: how do medical students perceive clinical learning climate?

PubMed

Yilmaz, Nilufer Demiral; Velipasaoglu, Serpil; Ozan, Sema; Basusta, Bilge Uzun; Midik, Ozlem; Mamakli, Sumer; Karaoglu, Nazan; Tengiz, Funda; Durak, Halil İbrahim; Sahin, Hatice

2016-01-01

The relationship between students and instructors is of crucial importance for the development of a positive learning climate. Learning climate is a multifaceted concept, and its measurement is a complicated process. The aim of this cross-sectional study was to determine medical students' perceptions about the clinical learning climate and to investigate differences in their perceptions in terms of various variables. Medical students studying at six medical schools in Turkey were recruited for the study. All students who completed clinical rotations, which lasted for 3 or more weeks, were included in the study (n=3,097). Data were collected using the Clinical Learning Climate Scale (CLCS). The CLCS (36 items) includes three subscales: clinical environment, emotion, and motivation. Each item is scored using a 5-point Likert scale (1: strongly disagree to 5: strongly agree). The response rate for the trainees was 69.67% (n=1,519), and for the interns it was 51.47% (n=917). The mean total CLCS score was 117.20±17.19. The rotation during which the clinical learning climate was perceived most favorably was the Physical Therapy and Rehabilitation rotation (mean score: 137.77). The most negatively perceived rotation was the General Internal Medicine rotation (mean score: 104.31). There were significant differences between mean total scores in terms of trainee/intern characteristics, internal medicine/surgical medicine rotations, and perception of success. The results of this study drew attention to certain aspects of the clinical learning climate in medical schools. Clinical teacher/instructor/supervisor, clinical training programs, students' interactions in clinical settings, self-realization, mood, students' intrinsic motivation, and institutional commitment are important components of the clinical learning climate. For this reason, the aforementioned components should be taken into consideration in studies aiming to improve clinical learning climate.

Women's Health Curriculum for Internal Medicine Residents: Development, Implementation, and Evaluation.

PubMed

Davisson, Laura; Nuss, Michelle; Cottrell, Scott

2010-09-01

Women's health knowledge and skills are important for physicians, but training is often inadequate. The objective of this project was to develop, implement, and evaluate a women's health curriculum for an internal medicine residency program. After assessing institutional factors, we developed a curriculum for a multidisciplinary clinical rotation with a web-based tutorial. We recruited faculty from several specialties relevant to the care of women to precept for the rotation and/or to provide teaching materials for the tutorial. The curriculum for the 1-month rotation covered most of the recommended women's health topics. Internal medicine residents worked in a variety of clinical settings and were assigned to a web-based tutorial and a pretest and posttest. A statistically significant increase was seen in participants' mean posttest (71.7%) versus pretest (61.1%) scores (difference, 10.7%; 95% confidence interval [CI]: 4.7-16.6; P  =  .0009). No difference was seen in controls' mean posttest (56.5%) versus pretest (57.2%) scores (difference, -0.7%; 95% CI: -12.1-10.7; P  =  .9). Mean rotation evaluation responses ranged from 7.09 to 7.45 on a 9-point scale. The majority (93%) of survey respondents agreed that the rotation increased their skills in caring for women, and all agreed the program was well organized and that it increased their awareness of women's health issues. A women's health curriculum using a web-based tutorial with a multidisciplinary clinical rotation can be successfully implemented in an internal medicine residency. The curriculum satisfied women's health training requirements, was associated with improvements in learning outcomes, and may be a model for women's health education.

A multicenter study: how do medical students perceive clinical learning climate?

PubMed

Yilmaz, Nilufer Demiral; Velipasaoglu, Serpil; Ozan, Sema; Basusta, Bilge Uzun; Midik, Ozlem; Mamakli, Sumer; Karaoglu, Nazan; Tengiz, Funda; Durak, Halil İbrahim; Sahin, Hatice

2016-01-01

Background The relationship between students and instructors is of crucial importance for the development of a positive learning climate. Learning climate is a multifaceted concept, and its measurement is a complicated process. The aim of this cross-sectional study was to determine medical students' perceptions about the clinical learning climate and to investigate differences in their perceptions in terms of various variables. Methods Medical students studying at six medical schools in Turkey were recruited for the study. All students who completed clinical rotations, which lasted for 3 or more weeks, were included in the study (n=3,097). Data were collected using the Clinical Learning Climate Scale (CLCS). The CLCS (36 items) includes three subscales: clinical environment, emotion, and motivation. Each item is scored using a 5-point Likert scale (1: strongly disagree to 5: strongly agree). Results The response rate for the trainees was 69.67% (n=1,519), and for the interns it was 51.47% (n=917). The mean total CLCS score was 117.20±17.19. The rotation during which the clinical learning climate was perceived most favorably was the Physical Therapy and Rehabilitation rotation (mean score: 137.77). The most negatively perceived rotation was the General Internal Medicine rotation (mean score: 104.31). There were significant differences between mean total scores in terms of trainee/intern characteristics, internal medicine/surgical medicine rotations, and perception of success. Conclusion The results of this study drew attention to certain aspects of the clinical learning climate in medical schools. Clinical teacher/instructor/supervisor, clinical training programs, students' interactions in clinical settings, self-realization, mood, students' intrinsic motivation, and institutional commitment are important components of the clinical learning climate. For this reason, the aforementioned components should be taken into consideration in studies aiming to improve clinical learning climate.

Postoperative stiff shoulder after open rotator cuff repair: a 3- to 20-year follow-up study.

PubMed

Vastamäki, H; Vastamäki, M

2014-12-01

Stiffness after a rotator cuff tear is common. So is stiffness after an arthroscopic rotator cuff repair. In the literature, however, postoperative restriction of passive range of motion after open rotator cuff repair in shoulders with free passive range of motion at surgery has seldom been recognized. We hypothesize that this postoperative stiffness is more frequent than recognized and slows the primary postoperative healing after a rotator cuff reconstruction. We wondered how common is postoperative restriction of both active and passive range of motion after open rotator cuff repair in shoulders with free passive preoperative range of motion, how it recovers, and whether this condition influences short- and long-term results of surgery. We also explored factors predicting postoperative shoulder stiffness. We retrospectively identified 103 postoperative stiff shoulders among 416 consecutive open rotator cuff repairs, evaluating incidence and duration of stiffness, short-term clinical results and long-term range of motion, pain relief, shoulder strength, and functional results 3-20 (mean 8.7) years after surgery in 56 patients. The incidence of postoperative shoulder stiffness was 20%. It delayed primary postoperative healing by 3-6 months and resolved during a mean 6.3 months postoperatively. External rotation resolved first, corresponding to that of the controls at 3 months; flexion and abduction took less than 1 year after surgery. The mean summarized range of motion (flexion + abduction + external rotation) increased as high as 93% of the controls' range of motion by 6 months and 100% by 1 year. Flexion, abduction, and internal rotation improved to the level of the contralateral shoulders as did pain, strength, and function. Age at surgery and condition of the biceps tendon were related to postoperative stiffness. Postoperative stiff shoulder after open rotator cuff repair is a common complication resolving in 6-12 months with good long-term results. © The Finnish Surgical Society 2013.

Perception of physicians about medical education received during their Nephrology residency training in Peru.

PubMed

Herrera-Añazco, Percy; Bonilla-Vargas, Luis; Hernandez, Adrian V; Silveira-Chau, Manuela

2015-01-01

In Peru there are different hospitals and university programs for training of specialists in nephrology. To assess the perception of physicians who attend such programs. We carried out a descriptive cross-sectional national-level study in physicians who were in the last two years of nephrology training during February 2012 and who had graduated from it in 2010 and 2011. A self-applied questionnaire was developed along with the Peruvian Society of Nephrology based on international standards. The questionnaire evaluated: mentoring, clinical training, procedures, external rotations, research and global perception. Forty doctors were surveyed nationwide. 82.5% had tutors, 22.5% of them said their support was poor. A 27.5% described their theoretical formation as deficient. The practical training was perceived as acceptable globally; however, improvements in training on peritoneal dialysis and reading kidney transplant biopsies are necessary. A 90% have national external rotations and 65% reported to have an international rotation. In the assessment of research, 77.5% thought this is deficient. In addition, 82.5% believed that residency should last four years. However, 60% reported that their residency training was good. There is a decrease in the positive perception of the aspects studied among residents regarding graduates. The overall perception of nephrology residency training was considered good; however, areas of tutoring, and academic and research activities on average were deficient.

Improved training of house officers in a rheumatology consult service.

PubMed

Mazzuca, S A; Brandt, K D; Katz, B P

1993-06-01

This study examined whether the clinical environment could be used to increase internal medicine house officers' adoption of care recommendations taught in a didactic conference. Subjects were 11 internal medicine house officers who served 6-week rheumatology elective rotations. At the start of each of four rotation periods, house officers attended a 1-hour conference in which periarticular rheumatic disorders associated with knee pain (anserine bursitis, pseudothrombophlebitis) and shoulder pain (bicipital tendinitis) were discussed. All house officers also practiced physical examination techniques on anatomic models simulating the disorders. During alternate rotation periods, reminder sheets were appended to the records of arthritis patients with histories of chronic knee or shoulder pain. The frequency with which house officers followed conference recommendations was documented by direct observation (6 house officers in 17 encounters with reminders, 5 house officers in 30 encounters without reminders). Specific questioning about a recent history of knee or shoulder pain and the performance of four of five recommended physical examination maneuvers were increased significantly by reminder sheets in patients' charts (P < 0.05 for all). Although rheumatology faculty often have limited options available to increase the number of house officer trainees or to intensify clinical activity, qualitative improvements within existing logistic parameters are feasible by assuring that the clinical environment (e.g., patient records) contains salient cues that will prompt desired actions.

Internal performance of a nonaxisymmetric nozzle with a rotating upper flap and a center-pivoted lower flap

NASA Technical Reports Server (NTRS)

Wing, David J.; Leavitt, Laurence D.; Re, Richard J.

1993-01-01

An investigation was conducted at wind-off conditions in the static-test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance characteristics of a single expansion-ramp nozzle with thrust-vectoring capability to 105 degrees. Thrust vectoring was accomplished by the downward rotation of an upper flap with adaptive capability for internal contouring and a corresponding rotation of a center-pivoted lower flap. The static internal performance of configurations with pitch thrust-vector angles of 0 degrees, 60 degrees, and 105 degrees each with two throat areas, was investigated. The nozzle pressure ratio was varied from 1.5 to approximately 8.0 (5.0 for the maximum throat area configurations). Results of this study indicated that the nozzle configuration of the present investigation, when vectored, provided excellent flow-turning capability with relatively high levels of internal performance. In all cases, the thrust vector angle was a function of the nozzle pressure ratio. This result is expected because the flow is bounded by a single expansion surface on both vectored- and unvectored-nozzle geometries.

Effects of Fatigue on Driving Safety: A Comparison of Brake Reaction Times in Night Float and Postcall Physicians in Training

PubMed Central

Talusan, Paul G.; Long, Theodore; Halim, Andrea; Guliani, Laura; Carroll, Nicole; Reach, John

2014-01-01

Background Concerns about duty hour and resident safety have fostered discussion about postshift fatigue and driving impairment. Objective We assessed how converting to a night float schedule for overnight coverage affected driving safety for trainees. Methods Brake reaction times were measured for internal medicine and orthopaedic surgery resident volunteers after a traditional 28-hour call shift and after a night float shift. We conducted matched paired t tests of preshift and postshift reaction time means. Participants also completed the Epworth Sleepiness Scale pre- and postshift. Results From June to July 2013, we enrolled 58 interns and residents (28 orthopaedic surgery, 30 internal medicine). We included 24 (41%) trainees on night float rotations and 34 (59%) trainees on traditional 28-hour call shifts. For all residents on night float rotations, there was no significant difference pre- and postshift. An increase in reaction times was noted among trainees on 28-hour call rotations. This included no effect on reaction times for internal medicine trainees pre- and postshift, and an increase in reaction times for orthopaedic trainees. For both night float and traditional call groups, there were significant increases in the Epworth Sleepiness Scale. Conclusions Trainees on traditional 28-hour call rotations had significantly worse postshift brake reaction times, whereas trainees on night float rotations had no difference. Orthopaedic trainees had significant differences in brake reaction times after a traditional call shift. PMID:26140113

A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial Evaluating the Effectiveness of Daily Vibration After Arthroscopic Rotator Cuff Repair.

PubMed

Lam, Patrick H; Hansen, Kaitlyn; Keighley, Geffrey; Hackett, Lisa; Murrell, George A C

2015-11-01

Rotator cuff repair is a common method to treat rotator cuff tears; however, retear rates remain high. High-frequency, low-magnitude vibration has been demonstrated to promote new bone formation in both animal models and in humans. This type of mechanical stimulation applied postoperatively will enhance tendon-to-bone healing and reduce postoperative retear rates. Randomized controlled trial; Level of evidence, 1. A randomized, double-blinded, placebo-controlled clinical trial was conducted to investigate the effects of 5 minutes of 80-Hz vibration applied daily after arthroscopic rotator cuff repair for 6 months on postoperative rotator cuff healing. The primary outcome was ultrasound-assessed repair integrity at 6 months after repair. Recruited patients were randomized into 2 groups: one group received a vibration device that oscillated at 80 Hz, and the other group received a placebo device. The postoperative retear rates of both groups were similar (9.1% [5/55] in the vibration group, and 9.3% [5/54] in the placebo group) at 6 months as determined by ultrasound imaging. Vibration did provide acute pain relief at 6 weeks after surgery (visual analog scale [VAS] score, 2.24 ± 0.29 cm) compared with placebo (VAS score, 3.67 ± 0.48 cm) (P < .003). Six months after surgery, both groups had significant reductions in pain during overhead activities, at rest, and during sleep and overall shoulder pain compared with before surgery (P < .001). Both the vibration and placebo groups had significant increases in shoulder strength with abduction in the scapular plane, adduction, liftoff, internal rotation, and external rotation 6 months after surgery. Statistical analysis showed that vibration was not a contributing factor at improving these parameters in these periods. High-frequency, low-magnitude vibration did provide acute pain relief on application 6 weeks after arthroscopic rotator cuff repair surgery. However, vibration did not improve tendon-to-bone healing, shoulder range of motion, shoulder strength, or shoulder pain with activities, at rest, and at night when compared with placebo. © 2015 The Author(s).

Strength Asymmetry of the Shoulders in Elite Volleyball Players

PubMed Central

Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

2014-01-01

Context: Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. Objective: To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Design: Descriptive laboratory study. Patients or Other Participants: A sample of 183 volleyball players (99 men, 84 women). Main Outcome Measure(s): We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Results: Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. Conclusions: In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male volleyball players. Isokinetic shoulder testing may reveal important information about the possible risk factors for shoulder injuries, so we recommend including it in the functional screening of volleyball players. PMID:24673238

Strength asymmetry of the shoulders in elite volleyball players.

PubMed

Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

2014-01-01

Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Descriptive laboratory study. A sample of 183 volleyball players (99 men, 84 women). We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male volleyball players. Isokinetic shoulder testing may reveal important information about the possible risk factors for shoulder injuries, so we recommend including it in the functional screening of volleyball players.

Exploring the origin of the internal rotational barrier for molecules with one rotatable dihedral angle

PubMed Central

Liu, Shubin; Govind, Niranjan; Pedersen, Lee G.

2008-01-01

Continuing our recent endeavor, we systematically investigate in this work the origin of internal rotational barriers for small molecules using the new energy partition scheme proposed recently by one of the authors [S. B. Liu, J. Chem. Phys. 126, 244103 (2007)], where the total electronic energy is decomposed into three independent components, steric, electrostatic, and fermionic quantum. Specifically, we focus in this work on six carbon, nitrogen, and oxygen containing hydrides, CH3CH3, CH3NH2, CH3OH, NH2NH2, NH2OH, and H2O2, with only one rotatable dihedral angle ∠H–X–Y–H (X,Y=C,N,O). The relative contributions of the different energy components to the total energy difference as a function of the internal dihedral rotation will be considered. Both optimized-geometry (adiabatic) and fixed-geometry (vertical) differences are examined, as are the results from the conventional energy partition and natural bond orbital analysis. A wealth of strong linear relationships among the total energy difference and energy component differences for different systems have been observed but no universal relationship applicable to all systems for both cases has been discovered, indicating that even for simple systems such as these, there exists no omnipresent, unique interpretation on the nature and origin of the internal rotation barrier. Different energy components can be employed for different systems in the rationalization of the barrier height. Confirming that the two differences, adiabatic and vertical, are disparate in nature, we find that for the vertical case there is a unique linear relationship applicable to all the six molecules between the total energy difference and the sum of the kinetic and electrostatic energy differences. For the adiabatic case, it is the total potential energy difference that has been found to correlate well with the total energy difference except for ethane whose rotation barrier is dominated by the quantum effect. PMID:19044862

The Effect of Arch Drop on Tibial Rotation and Tibiofemoral Contact Stress in Postpartum Women.

PubMed

Rabe, Kaitlin; Segal, Neil A; Waheed, Saphia; Anderson, Donald D

2018-04-26

Women are at greater risk for knee osteoarthritis and numerous other lower limb musculoskeletal disorders. Arch drop during pregnancy and the resultant excessive pronation of the feet may alter loading patterns and contribute to the greater prevalence of knee osteoarthritis in women. To determine the effect of arch drop on tibial rotation and tibiofemoral contact stress. Interventional study with internal control. Biomechanics laboratory. Eleven postpartum women (age 33.4 ± 5.3 years, body mass 76.1 ± 13.5 kg) who had lost arch height with pregnancy in a previous study. Subjects underwent standing computed tomography (SCT) with their knees in a 20° fixed-flexed position with and without semirigid arch supports to reconstitute prepregnancy arch height. Magnetic resonance imaging of the knee was acquired at a flexion angle equivalent to that of SCT. Bone and cartilage were manually segmented on the magnetic resonance images and segmented surfaces were registered to the 3-dimensional SCT image sets for the arch-supported and -unsupported conditions. These models were used to measure changes in tibial rotation, as well as to estimate contact stress in the medial and lateral tibiofemoral compartments, using computational methods. Change in tibial rotation and tibiofemoral contact stress with arch drop. Arch drop resulted in a mean tibial internal rotation of 0.75 ± 1.33° (P < .05). Changes in mean or peak contact stress were not detected. Arch drop causes internal tibial rotation, resulting in a shift in the tibiofemoral articulation. An associated increase in contact stress was not detected. Internal rotation of the tibia increases stress on the anterior cruciate ligament and menisci, potentially explaining the greater prevalence of knee disorders in postpartum women. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Rotation-induced nonlinear wavepackets in internal waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitfield, A. J., E-mail: ashley.whitfield.12@ucl.ac.uk; Johnson, E. R., E-mail: e.johnson@ucl.ac.uk

2014-05-15

The long time effect of weak rotation on an internal solitary wave is the decay into inertia-gravity waves and the eventual formation of a localised wavepacket. Here this initial value problem is considered within the context of the Ostrovsky, or the rotation-modified Korteweg-de Vries (KdV), equation and a numerical method for obtaining accurate wavepacket solutions is presented. The flow evolutions are described in the regimes of relatively-strong and relatively-weak rotational effects. When rotational effects are relatively strong a second-order soliton solution of the nonlinear Schrödinger equation accurately predicts the shape, and phase and group velocities of the numerically determined wavepackets.more » It is suggested that these solitons may form from a local Benjamin-Feir instability in the inertia-gravity wave-train radiated when a KdV solitary wave rapidly adjusts to the presence of strong rotation. When rotational effects are relatively weak the initial KdV solitary wave remains coherent longer, decaying only slowly due to weak radiation and modulational instability is no longer relevant. Wavepacket solutions in this regime appear to consist of a modulated KdV soliton wavetrain propagating on a slowly varying background of finite extent.« less

Generalized YORP evolution: Onset of tumbling and new asymptotic states

NASA Astrophysics Data System (ADS)

Vokrouhlický, D.; Breiter, S.; Nesvorný, D.; Bottke, W. F.

2007-11-01

Asteroids have a wide range of rotation states. While the majority spin a few times to several times each day in principal axis rotation, a small number spin so slowly that they have somehow managed to enter into a tumbling rotation state. Here we investigate whether the Yarkovsky-Radzievskii-O'Keefe-Paddack (YORP) thermal radiation effect could have produced these unusual spin states. To do this, we developed a Lie-Poisson integrator of the orbital and rotational motion of a model asteroid. Solar torques, YORP, and internal energy dissipation were included in our model. Using this code, we found that YORP can no longer drive the spin rates of bodies toward values infinitely close to zero. Instead, bodies losing too much rotation angular momentum fall into chaotic tumbling rotation states where the spin axis wanders randomly for some interval of time. Eventually, our model asteroids reach rotation states that approach regular motion of the spin axis in the body frame. An analytical model designed to describe this behavior does a good job of predicting how and when the onset of tumbling motion should take place. The question of whether a given asteroid will fall into a tumbling rotation state depends on the efficiency of its internal energy dissipation and on the precise way YORP modifies the spin rates of small bodies.

Ultrasound evaluation of muscle thickness changes in the external oblique, internal oblique, and transversus abdominis muscles considering the influence of posture and muscle contraction.

PubMed

Sugaya, Tomoaki; Abe, Yota; Sakamoto, Masaaki

2014-09-01

[Purpose] The aim of this study was to investigate muscle thickness changes in the external oblique (EO), internal oblique (IO), and transversus abdominis (TrA) muscles between the neutral position and trunk rotation, under a state of rest without voluntary contractions, and isometric contractions to both sides with resistance of 50% of the maximum trunk rotation strength. [Subjects] The subjects of this study were 21 healthy young men. [Methods] Muscle thickness changes in the EO, IO, and TrA in each position and state were evaluated by ultrasound. The range of motion at maximum trunk rotation and the maximum strength of trunk rotation were measured using a hand-held dynamometer. [Results] In the neutral position and at 50% trunk rotation to the right side, the thicknesses of the IO and TrA significantly increased with resistance. In both states, the thicknesses of the IO and TrA significantly increased at 50% trunk rotation to the right side. [Conclusion] The muscular contractions of the IO and TrA were stronger during ipsilateral rotation than in the neutral position and with resistance than at rest. Moreover, the muscular contraction was strongest in the resistive state during ipsilateral rotation.

Numerical investigation of the onset of centrifugal buoyancy in a rotating cavity

NASA Astrophysics Data System (ADS)

Pitz, Diogo B.; Marxen, Olaf; Chew, John

2016-11-01

Buoyancy-induced flows in a differentially heated rotating annulus present a multitude of dynamics when control parameters such as rotation rate, temperature difference and Prandtl number are varied. Whilst most of the work in this area has been motivated by applications involving geophysics, the problem of buoyancy-induced convection in rotating systems is also relevant in industrial applications such as the flow between rotating disks of turbomachinery internal air systems, in which buoyancy plays a major role and poses a challenge to accurately predict temperature distributions and heat transfer rates. In such applications the rotational speeds involved are very large, so that the centrifugal accelerations induced are much higher than gravity. In this work we perform direct numerical simulations and linear stability analysis of flow induced by centrifugal buoyancy in a sealed rotating annulus of finite gap with flat end-walls, using a canonical setup representative of an internal air system rotating cavity. The analysis focuses on the behaviour of small-amplitude disturbances added to the base flow, and how those affect the onset of Rossby waves and, ultimately, the transition to a fully turbulent state where convection columns no longer have a well-defined structure. Diogo B. Pitz acknowledges the financial support from the Capes foundation through the Science without Borders program.

Shoulder isokinetic profile of male handball players of the Brazilian National Team

PubMed Central

Andrade, Marília S.; Vancini, Rodrigo L.; de Lira, Claudio A. B.; Mascarin, Naryana C.; Fachina, Rafael J. F. G.; da Silva, Antonio C.

2013-01-01

Background Data obtained on an isokinetic dynamometer are useful to characterize muscle status and have been reported in muscle imbalance studies in different types of sport. However, few studies have assessed elite handball players to establish reference values. Objective The purpose of this study was to compare, for the dominant (D) and non-dominant (ND) side, the isokinetic profile of shoulder rotator muscle strength between male handball players (H) and asymptomatic non-athletes (NA). Method Isokinetic concentric and eccentric strength tests for D upper limbs were performed by the H group (n=20) and the NA group (n=12). Internal and external rotator muscle peak torque in concentric action was assessed at 60°/s and 300°/s and in eccentric action at 300°/s. We also calculated conventional balance (the ratio of external rotator peak torque to internal rotator peak torque in concentric action) and functional balance (the ratio of external rotator peak torque in eccentric action to internal rotator peak torque in concentric action). Results In the H group, dominant limbs were stronger in concentric action for external rotation at 60 and 300°/s. The conventional balance ratio for the D side was significantly lower at 60 and 300°/s for H compared to NA. The functional ratio for the D side was significantly lower at 300º/s for H compared to NA. Conclusions Compared to asymptomatic non-athletes, handball players presented significant muscular imbalance resulting from daily sports practice, a known risk factor for shoulder injuries. PMID:24271090

Gas-Phase Structures of Linalool and Coumarin Studied by Microwave Spectroscopy

NASA Astrophysics Data System (ADS)

Nguyen, H. V. L.; Stahl, W.; Grabow, J.-U.

2013-06-01

The microwave spectra of two natural substances, linalool and coumarin, were recorded in the microwave range from 9 to 16 GHz and 8.5 to 10.5 GHz, respectively.Linalool is an acyclic monoterpene and the main component of lavender oil. It has a structure with many possible conformations. The geometry of the lowest energy conformer has been determined by a combination of microwave spectroscopy and quantum chemical calculations. Surprisingly, a globular rather than a prolate shape was found. This structure is probably stabilized by a π interaction between two double bonds which are arranged in two stacked layers of atoms within the molecule. A-E splittings due to the internal rotation of one methyl group could be resolved and the barrier to internal rotation was determined to be 400.20(64) cm^{-1}. The standard deviation of the fit was close to experimental accuracy. For an identification of the observed conformer not only the rotational constants but also the internal rotation parameters of one of the methyl groups were needed. Coumarin is a widely used flavor in perfumery as sweet woodruff scent. The aromatic structure allows solely for one planar conformer, which was found under molecular beam conditions and compared to other molecules with similar structures. Here, the rotational spectrum could be described by a set of parameters including the rotational constants and the centrifugal distortion constants using a semi-rigid molecule Hamiltonian. Furthermore, the rotational transitions of all nine ^{13}C isotopologues were measured in natural abundance. As a consequence, the microwave structure of coumarin could be almost completely determined.

The influence of motion control shoes on the running gait of mature and young females.

PubMed

Lilley, Kim; Stiles, Vicky; Dixon, Sharon

2013-03-01

This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm. 15 mature (40-60 years) and 15 young (18-25 years) females performed 10 running trials at 3.5ms(-1)±5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics. In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p<0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p<0.05). No between shoe differences in knee external adductor moment were observed. A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment. Copyright © 2012 Elsevier B.V. All rights reserved.

STELLAR DYNAMOS AND CYCLES FROM NUMERICAL SIMULATIONS OF CONVECTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dubé, Caroline; Charbonneau, Paul, E-mail: dube@astro.umontreal.ca, E-mail: paulchar@astro.umontreal.ca

We present a series of kinematic axisymmetric mean-field αΩ dynamo models applicable to solar-type stars, for 20 distinct combinations of rotation rates and luminosities. The internal differential rotation and kinetic helicity profiles required to calculate source terms in these dynamo models are extracted from a corresponding series of global three-dimensional hydrodynamical simulations of solar/stellar convection, so that the resulting dynamo models end up involving only one free parameter, namely, the turbulent magnetic diffusivity in the convecting layers. Even though the αΩ dynamo solutions exhibit a broad range of morphologies, and sometimes even double cycles, these models manage to reproduce relativelymore » well the observationally inferred relationship between cycle period and rotation rate. On the other hand, they fail in capturing the observed increase of magnetic activity levels with rotation rate. This failure is due to our use of a simple algebraic α-quenching formula as the sole amplitude-limiting nonlinearity. This suggests that α-quenching is not the primary mechanism setting the amplitude of stellar magnetic cycles, with magnetic reaction on large-scale flows emerging as the more likely candidate. This inference is coherent with analyses of various recent global magnetohydrodynamical simulations of solar/stellar convection.« less

The role of angular momentum in the superrotor theory for rovibrational motion of extremely flexible molecules

NASA Astrophysics Data System (ADS)

Schmiedt, Hanno; Jensen, Per; Schlemmer, Stephan

2017-12-01

Recently, we proposed a novel approach to the description of the rotation-vibration motion for extremely flexible molecules (Schmiedt et al., 2016, 2017). Such molecules have multiple very "soft" vibrational modes and so, they lack a well-defined equilibrium structure. We have applied the new superrotor model to the prototype example of an extremely flexible molecule, CH5+, for which we combine two, essentially free vibrational modes (describing internal rotation) with the over-all rotation of the molecule and consider the resulting motion as a free rotation in five-dimensional space, with a Hamiltonian whose symmetry is described by SO(5), the five-dimensional rotation group. In the present work we discuss the correlation between the superrotor energies and those obtained in the more usual situation of the internal and over-all rotations being separable, and we give an initial discussion of the selection rules for electric dipole transitions obtained in the superrotor approach. Such selection rules are required for a detailed comparison between the superrotor predictions and the available, experimentally derived energy spacings (Asvany et al., 2015; Brackertz, 2016).

Perspectives of South American physicians hosting foreign rotators in emergency medicine

PubMed Central

2014-01-01

Background Emergency Medicine (EM) is increasingly becoming an international field. The number of fellowships in International EM in the USA is growing along with opportunities to complete international health electives (IHEs) during residency training. The impact on host institutions, however, has not been adequately investigated. The objective of this study is to assess the experience of several South American hospitals hosting foreign EM residents completing IHEs. Methods Anonymous, semi-structured one-on-one interviews were conducted with physicians working in Emergency Departments in three hospitals in Lima, Peru and one hospital in Buenos Aires, Argentina. All participants reported previously working with EM foreign rotators. Interviews were analyzed qualitatively and coded for common themes. Results Three department chairs, six residents, and 15 attending physicians were interviewed (total = 24). After qualitative analysis of interviews, two broad theme categories emerged: Benefits and Challenges. Most commonly reported benefits were knowledge sharing about emergency medical systems (78%), medical knowledge transfer (58%), and long-term relationship formation (42%). Top challenges included rotator Spanish language proficiency (70%) lack of reciprocity (58%), and level of training and rotation length (25%). Spanish proficiency related directly to how involved rotators became in patient care (e.g., taking a history, participating in rounds) but was not completely prohibitive, as a majority of physicians interviewed felt comfortable speaking in English. Lack of reciprocity refers to the difficulty of sending host physicians abroad as well as failed attempts at building long-lasting relationships with foreign institutions. Lastly, 25% preferred rotators to stay for at least 1 month and rotate in the last year of EM residency. This latter preference increased knowledge transfer from rotator to host. Conclusions Our research identified benefits and challenges of IHEs in Emergency Medicine from the perspective of physician hosts in several hospitals in South America. Our results suggest that IHEs function best when EM residents rotate later in residency training and when relationships are maintained and deepened among those involved including host physicians, rotators, and institutions. This leads to future rotators, project collaboration, research, and publications which not only benefit individuals involved but also the wider field of Emergency Medicine. PMID:25635188

Perspectives of South American physicians hosting foreign rotators in emergency medicine.

PubMed

O'Donnell, Steve; Adler, David H; Inboriboon, Pholaphat Charles; Alvarado, Hermenegildo; Acosta, Raul; Godoy-Monzon, Daniel

2014-01-01

Emergency Medicine (EM) is increasingly becoming an international field. The number of fellowships in International EM in the USA is growing along with opportunities to complete international health electives (IHEs) during residency training. The impact on host institutions, however, has not been adequately investigated. The objective of this study is to assess the experience of several South American hospitals hosting foreign EM residents completing IHEs. Anonymous, semi-structured one-on-one interviews were conducted with physicians working in Emergency Departments in three hospitals in Lima, Peru and one hospital in Buenos Aires, Argentina. All participants reported previously working with EM foreign rotators. Interviews were analyzed qualitatively and coded for common themes. Three department chairs, six residents, and 15 attending physicians were interviewed (total = 24). After qualitative analysis of interviews, two broad theme categories emerged: Benefits and Challenges. Most commonly reported benefits were knowledge sharing about emergency medical systems (78%), medical knowledge transfer (58%), and long-term relationship formation (42%). Top challenges included rotator Spanish language proficiency (70%) lack of reciprocity (58%), and level of training and rotation length (25%). Spanish proficiency related directly to how involved rotators became in patient care (e.g., taking a history, participating in rounds) but was not completely prohibitive, as a majority of physicians interviewed felt comfortable speaking in English. Lack of reciprocity refers to the difficulty of sending host physicians abroad as well as failed attempts at building long-lasting relationships with foreign institutions. Lastly, 25% preferred rotators to stay for at least 1 month and rotate in the last year of EM residency. This latter preference increased knowledge transfer from rotator to host. Our research identified benefits and challenges of IHEs in Emergency Medicine from the perspective of physician hosts in several hospitals in South America. Our results suggest that IHEs function best when EM residents rotate later in residency training and when relationships are maintained and deepened among those involved including host physicians, rotators, and institutions. This leads to future rotators, project collaboration, research, and publications which not only benefit individuals involved but also the wider field of Emergency Medicine.

High-Accuracy Ring Laser Gyroscopes: Earth Rotation Rate and Relativistic Effects

NASA Astrophysics Data System (ADS)

Beverini, N.; Di Virgilio, A.; Belfi, J.; Ortolan, A.; Schreiber, K. U.; Gebauer, A.; Klügel, T.

2016-06-01

The Gross Ring G is a square ring laser gyroscope, built as a monolithic Zerodur structure with 4 m length on all sides. It has demonstrated that a large ring laser provides a sensitivity high enough to measure the rotational rate of the Earth with a high precision of ΔΩE < 10-8. It is possible to show that further improvement in accuracy could allow the observation of the metric frame dragging, produced by the Earth rotating mass (Lense-Thirring effect), as predicted by General Relativity. Furthermore, it can provide a local measurement of the Earth rotational rate with a sensitivity near to that provided by the international system IERS. The GINGER project is intending to take this level of sensitivity further and to improve the accuracy and the long-term stability. A monolithic structure similar to the G ring laser is not available for GINGER. Therefore the preliminary goal is the demonstration of the feasibility of a larger gyroscope structure, where the mechanical stability is obtained through an active control of the geometry. A prototype moderate size gyroscope (GP-2) has been set up in Pisa in order to test this active control of the ring geometry, while a second structure (GINGERino) has been installed inside the Gran Sasso underground laboratory in order to investigate the properties of a deep underground laboratory in view of an installation of a future GINGER apparatus. The preliminary data on these two latter instruments are presented.

The internal representation of head orientation differs for conscious perception and balance control.

PubMed

Dalton, Brian H; Rasman, Brandon G; Inglis, J Timothy; Blouin, Jean-Sébastien

2017-04-15

We tested perceived head-on-feet orientation and the direction of vestibular-evoked balance responses in passively and actively held head-turned postures. The direction of vestibular-evoked balance responses was not aligned with perceived head-on-feet orientation while maintaining prolonged passively held head-turned postures. Furthermore, static visual cues of head-on-feet orientation did not update the estimate of head posture for the balance controller. A prolonged actively held head-turned posture did not elicit a rotation in the direction of the vestibular-evoked balance response despite a significant rotation in perceived angular head posture. It is proposed that conscious perception of head posture and the transformation of vestibular signals for standing balance relying on this head posture are not dependent on the same internal representation. Rather, the balance system may operate under its own sensorimotor principles, which are partly independent from perception. Vestibular signals used for balance control must be integrated with other sensorimotor cues to allow transformation of descending signals according to an internal representation of body configuration. We explored two alternative models of sensorimotor integration that propose (1) a single internal representation of head-on-feet orientation is responsible for perceived postural orientation and standing balance or (2) conscious perception and balance control are driven by separate internal representations. During three experiments, participants stood quietly while passively or actively maintaining a prolonged head-turned posture (>10 min). Throughout the trials, participants intermittently reported their perceived head angular position, and subsequently electrical vestibular stimuli were delivered to elicit whole-body balance responses. Visual recalibration of head-on-feet posture was used to determine whether static visual cues are used to update the internal representation of body configuration for perceived orientation and standing balance. All three experiments involved situations in which the vestibular-evoked balance response was not orthogonal to perceived head-on-feet orientation, regardless of the visual information provided. For prolonged head-turned postures, balance responses consistent with actual head-on-feet posture occurred only during the active condition. Our results indicate that conscious perception of head-on-feet posture and vestibular control of balance do not rely on the same internal representation, but instead treat sensorimotor cues in parallel and may arrive at different conclusions regarding head-on-feet posture. The balance system appears to bypass static visual cues of postural orientation and mainly use other sensorimotor signals of head-on-feet position to transform vestibular signals of head motion, a mechanism appropriate for most daily activities. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Internal Dynamics of Water Attached to a Photoacidic Substrate: High Resolution Electronic Spectroscopy of β-NAPHTHOL-WATER in the Gas Phase.

NASA Astrophysics Data System (ADS)

Fleisher, Adam J.; Young, Justin W.; Pratt, David W.

2010-06-01

An understanding of the structure and internal dynamics of water attached to the photoacid β-naphthol is attainable through rotationally resolved electronic spectroscopy. Here, we present rotational constants for the 1:1 acid-base cluster in both S0 and S1, which provide the location of water within the cluster, as well as the barrier height to internal rotation of water in each electronic state. The barrier height decreases slightly upon excitation, from 206 wn in S0, to 182 wn in S1. There is also little evidence of a large change in water location, orientation, or overall hydrogen bond length upon irradiation with UV light. Thus, a single water molecule has relatively little affect on the substrate photo-acidity measured in the liquid phase.

Numerical assessment of factors affecting nonlinear internal waves in the South China Sea

NASA Astrophysics Data System (ADS)

Li, Qiang

2014-02-01

Nonlinear internal waves in the South China Sea exhibit diverse characteristics, which are associated with the complex conditions in Luzon Strait, such as the double ridge topography, the Earth’s rotation, variations in stratification and the background current induced by the Kuroshio. These effects are individually assessed using the MITgcm. The performance of the model is first validated through comparison with field observations. Because of in-phased ray interaction, the western ridge in Luzon Strait intensifies the semidiurnal internal tides generated from the eastern ridge, thus reinforcing the formation of nonlinear internal waves. However, the ray interaction for K1 forcing becomes anti-phased so that the K1 internal tide generation is reduced by the western ridge. Not only does the rotational dispersion suppress internal tide generation, it also inhibits nonlinear steepening and consequent internal solitary wave formation. As a joint effect, the double ridges and the rotational dispersion result in a paradoxical phenomenon: diurnal barotropic tidal forcing is dominant in Luzon Strait, but semidiurnal internal tides prevail in the deep basin of the South China Sea. The seasonal variation of the Kuroshio is consistent with the seasonal appearance of nonlinear internal waves in the South China Sea. The model results show that the westward inflow due to the Kuroshio intrusion reduces the amplitude of internal tides in the South China Sea, causing the weakening or absence of internal solitary waves. Winter stratification cannot account for the significant reduction of nonlinear internal waves, because the amplitude growth of internal tides due to increased thermocline tilting counteracts the reduced nonlinearity caused by thermocline deepening.

AN ACTIVITY–ROTATION RELATIONSHIP AND KINEMATIC ANALYSIS OF NEARBY MID-TO-LATE-TYPE M DWARFS

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, Andrew A.; Weisenburger, Kolby L.; Irwin, Jonathan

Using spectroscopic observations and photometric light curves of 238 nearby M dwarfs from the MEarth exoplanet transit survey, we examine the relationships between magnetic activity (quantified by Hα emission), rotation period, and stellar age. Previous attempts to investigate the relationship between magnetic activity and rotation in these stars were hampered by the limited number of M dwarfs with measured rotation periods (and the fact that v sin i measurements probe only rapid rotation). However, the photometric data from MEarth allows us to probe a wide range of rotation periods for hundreds of M dwarf stars (from shorter than one tomore » longer than 100 days). Over all M spectral types that we probe, we find that the presence of magnetic activity is tied to rotation, including for late-type, fully convective M dwarfs. We also find evidence that the fraction of late-type M dwarfs that are active may be higher at longer rotation periods compared to their early-type counterparts, with several active, late-type, slowly rotating stars present in our sample. Additionally, we find that all M dwarfs with rotation periods shorter than 26 days (early-type; M1–M4) and 86 days (late-type; M5–M8) are magnetically active. This potential mismatch suggests that the physical mechanisms that connect stellar rotation to chromospheric heating may be different in fully convective stars. A kinematic analysis suggests that the magnetically active, rapidly rotating stars are consistent with a kinematically young population, while slow-rotators are less active or inactive and appear to belong to an older, dynamically heated stellar population.« less

Palaeomagnetic Constrains on the Timing and the Geographical Distribution of Tectonic Rotations in the Betic Chain, Southern Spain. A Review

NASA Astrophysics Data System (ADS)

Osete, M. L.; Villalain, J. J.; Pavon-Carrasco, F. J.; Palencia, A.

2009-05-01

The Betic Cordillera is the northern branch of the Betic-Rifean orogen, the westernmost segment of the Mediterranean Alpine orogenic system. Several palaeomagnetic studies have enhanced the important role that block rotations about vertical axes have played in the tectonic evolution of the region. In this work we present a review of published palaeomagnetic data. According with the rotational deformation, the Betics are divided into the central-western area and the eastern Betics. A sequence of rotations for the two regions is also proposed. In central and western Subbetics almost constant clockwise rotations of about 60 are documented in Jurassic limestones. The existence of a pervasive remagnetization of Jurassic limestones, which was coeval with the folding of the studied units and dated as post-Palaeogene, constrains the timing of tectonic rotations in western Subbetics. New palaeomagnetic data from Neogene sedimentary sequences in central Betics indicate that palaeomagnetic clockwise rotations continued after late Miocene. A similar pattern of 40 CW rotations occurred after 20-17 Ma was obtained from the study of the Ronda-Malaga peridotites (western Internal Betics). In eastern Subbetics a more heterogeneous pattern, including very high CW rotations has been observed. But recent rotational deformation in the Internal part of eastern Betics is CCW and related to the left-lateral strike-slip fault systems. Proposed kinematics models for the Betics are discussed under the light of the present available palaeomagnetic information.

An improved OpenSim gait model with multiple degrees of freedom knee joint and knee ligaments.

PubMed

Xu, Hang; Bloswick, Donald; Merryweather, Andrew

2015-08-01

Musculoskeletal models are widely used to investigate joint kinematics and predict muscle force during gait. However, the knee is usually simplified as a one degree of freedom joint and knee ligaments are neglected. The aim of this study was to develop an OpenSim gait model with enhanced knee structures. The knee joint in this study included three rotations and three translations. The three knee rotations and mediolateral translation were independent, with proximodistal and anteroposterior translations occurring as a function of knee flexion/extension. Ten elastic elements described the geometrical and mechanical properties of the anterior and posterior cruciate ligaments (ACL and PCL), and the medial and lateral collateral ligaments (MCL and LCL). The three independent knee rotations were evaluated using OpenSim to observe ligament function. The results showed that the anterior and posterior bundles of ACL and PCL (aACL, pACL and aPCL, pPCL) intersected during knee flexion. The aACL and pACL mainly provided force during knee flexion and adduction, respectively. The aPCL was slack throughout the range of three knee rotations; however, the pPCL was utilised for knee abduction and internal rotation. The LCL was employed for knee adduction and rotation, but was slack beyond 20° of knee flexion. The MCL bundles were mainly used during knee adduction and external rotation. All these results suggest that the functions of knee ligaments in this model approximated the behaviour of the physical knee and the enhanced knee structures can improve the ability to investigate knee joint biomechanics during various gait activities.

Three-dimensional knee motion before and after high tibial osteotomy for medial knee osteoarthritis.

PubMed

Takemae, Takashi; Omori, Go; Nishino, Katsutoshi; Terajima, Kazuhiro; Koga, Yoshio; Endo, Naoto

2006-11-01

High tibial osteotomy (HTO) is an established surgical option for treating medial knee osteoarthritis. HTO moves the mechanical load on the knee joint from the medial compartment to the lateral compartment by changing the leg alignment, but the effects of the operation remain unclear. The purpose of this study was to evaluate the change in three-dimensional knee motion before and after HTO, focusing on lateral thrust and screw home movement, and to investigate the relationship between the change in knee motion and the clinical results. A series of 19 patients with medial knee osteoarthritis who had undergone HTO were evaluated. We performed a clinical assessment, radiological evaluation, and motion analysis at 2.4 years postoperatively. The clinical assessment was performed using the Japanese Orthopaedic Association knee score. The score was significantly improved in all patients after operation. Motion analysis revealed that lateral thrust, which was observed in 18 of the 20 knees before operation, was reduced to 7 knees after operation. Regarding active terminal extension of the knee, three patterns of rotational movement were observed before operation: screw home movement (external rotation), reverse screw home movement (internal rotation), and no rotation. By contrast, after operation, only reverse screw home movement and no rotation were observed; the screw home movement disappeared in all patients. In the knees with reverse screw home movement after operation, the preoperative score was significantly lower than those in the knees with no rotation after operation. Kinetically, HTO was useful for suppressing lateral thrust in medial knee osteoarthritis, although the rotational movement of the knee joint was unchanged.

Seismic diagnosis from gravity modes strongly affected by rotation

NASA Astrophysics Data System (ADS)

Prat, Vincent; Mathis, Stéphane; Lignières, François; Ballot, Jérôme; Culpin, Pierre-Marie

2017-10-01

Most of the information we have about the internal rotation of stars comes from modes that are weakly affected by rotation, for example by using rotational splittings. In contrast, we present here a method, based on the asymptotic theory of Prat et al. (2016), which allows us to analyse the signature of rotation where its effect is the most important, that is in low-frequency gravity modes that are strongly affected by rotation. For such modes, we predict two spectral patterns that could be confronted to observed spectra and those computed using fully two-dimensional oscillation codes.

Peptide conjugated magnetic nanoparticles for magnetically mediated energy delivery to lung cancer cells

PubMed Central

Hauser, Anastasia K; Anderson, Kimberly W; Hilt, J Zach

2016-01-01

Aim: In the present study, we examine the effects of internalized peptide-conjugated iron oxide nanoparticles and their ability to locally convert alternating magnetic field (AMF) energy into other forms of energy (e.g., heat and rotational work). Materials & methods: Dextran-coated iron oxide nanoparticles were functionalized with a cell penetrating peptide and after internalization by A549 and H358 cells were activated by an AMF. Results: TAT-functionalized nanoparticles and AMF exposure increased reactive oxygen species generation compared with the nanoparticle system alone. The TAT-functionalized nanoparticles induced lysosomal membrane permeability and mitochondrial membrane depolarization, but these effects were not further enhanced by AMF treatment. Although not statistically significant, there are trends suggesting an increase in apoptosis via the Caspase 3/7 pathways when cells are exposed to TAT-functionalized nanoparticles combined with AMF. Conclusion: Our results indicate that internalized TAT-functionalized iron oxide nanoparticles activated by an AMF elicit cellular responses without a measurable temperature rise. PMID:27388639

The Mission Accessible Near-Earth Objects Survey (MANOS): photometric results

NASA Astrophysics Data System (ADS)

Thirouin, Audrey; Moskovitz, Nicholas; Binzel, Richard; Christensen, Eric J.; DeMeo, Francesca; Person, Michael J.; Polishook, David; Thomas, Cristina; Trilling, David E.; Willman, Mark; Hinkle, Mary L.; Burt, Brian; Avner, Dan

2016-10-01

The Mission Accessible Near-Earth Object Survey (MANOS) is a physical characterization survey of Near-Earth Objects (NEOs) to provide physical data for several hundred mission accessible NEOs across visible and near-infrared wavelengths. Using a variety of 1-m to 8-m class telescopes, we observe 5 to 10 newly discovered sub-km NEOs per month in order to derive their rotational properties and taxonomic class.Rotational data can provide useful information about physical properties, like shape, surface heterogeneity/homogeneity, density, internal structure, and internal cohesion. Here, we present results of the MANOS photometric survey for more than 200 NEOs. We report lightcurves from our first three years of observing and show objects with rotational periods from a couple of hours down to a few seconds. MANOS found the three fastest rotators known to date with rotational periods below 20s. A physical interpretation of these ultra-rapid rotators is that they are bound through a combination of cohesive and/or tensile strength rather than gravity. Therefore, these objects are important to understand the internal structure of NEOs. Rotational properties are used for statistical study to constrain overall properties of the NEO population. We also study rotational properties according to size, and dynamical class. Finally, we report a sample of NEOs that are fully characterized (lightcurve and visible spectra) as the most suitable candidates for a future robotic or human mission. Viable mission targets are objects with a rotational period >1h, and a delta-v lower than 12 km/s. Assuming the MANOS rate of object characterization, and the current NEO population estimates by Tricarico (2016), and by Harris and D'Abramo (2015), 10,000 to 1,000,000 NEOs with diameters between 10m and 1km are expected to be mission accessible. We acknowledge funding support from NASA NEOO grant number NNX14AN82G, and NOAO survey program.

Nonequilibrium dissipation-free transport in F₁-ATPase and the thermodynamic role of asymmetric allosterism.

PubMed

Kawaguchi, Kyogo; Sasa, Shin-Ichi; Sagawa, Takahiro

2014-06-03

F1-ATPase (or F1), the highly efficient and reversible biochemical engine, has motivated physicists as well as biologists to imagine the design principles governing machines in the fluctuating world. Recent experiments have clarified yet another interesting property of F1; the dissipative heat inside the motor is very small, irrespective of the velocity of rotation and energy transport. Conceptual interest is devoted to the fact that the amount of internal dissipation is not simply determined by the sequence of equilibrium pictures, but also relies on the rotational-angular dependence of nucleotide affinity, which is a truly nonequilibrium aspect. We propose that the totally asymmetric allosteric model (TASAM), where adenosine triphosphate (ATP) binding to F1 is assumed to have low dependence on the angle of the rotating shaft, produces results that are most consistent with the experiments. Theoretical analysis proves the crucial role of two time scales in the model, which explains the universal mechanism to produce the internal dissipation-free feature. The model reproduces the characteristic torque dependence of the rotational velocity of F1 and predicts that the internal dissipation upon the ATP synthesis direction rotation becomes large at the low nucleotide condition. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential.

PubMed

Dame, Don

1996-05-01

Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required. © 1996 International Society for Artificial Organs.

Spin-symmetry conversion and internal rotation in high J molecular systems

NASA Astrophysics Data System (ADS)

Mitchell, Justin; Harter, William

2006-05-01

Dynamics and spectra of molecules with internal rotation or rovibrational coupling is approximately modeled by rigid or semi-rigid rotors with attached gyroscopes. Using Rotational Energy (RE)^1 surfaces, high resolution molecular spectra for high angular momentum show two distinct but related phenomena; spin-symmetry conversion and internal rotation. For both cases the high total angular momentum allows for transitions that would otherwise be forbidden. Molecular body-frame J-localization effects associated with tight energy level-clusters dominate the rovibronic spectra of high symmetry molecules, particularly spherical tops at J>10. ^2 The effects include large and widespread spin-symmetry mixing contrary to conventional wisdom^3 about weak nuclear moments. Such effects are discussed showing how RE surface plots may predict them even at low J. Classical dynamics of axially constrained rotors are approximated by intersecting rotational-energy-surfaces (RES) that have (J-S).B.(J-S) forms in the limit of constraints that do no work. Semi-classical eigensolutions are compared to those found by direct diagonalization. ^1 W.G Hater, in Handbook of Atomic, Molecular and Optical Physics, edited by G.W.F Drake (Springer, Germany 2006) ^2 W. G. Harter, Phys. Rev. A24,192-262(1981). ^3 G. Herzberg, Infrared and Raman Spectra (VanNostrand 1945) pp. 458,463.

a Comparison of the Molecular Structures of C_4H_9OCH_3, C_4H_9SCH_3, C_5H_{11}OCH_3, and C_5H_{11}SCH_3 Using Microwave Spectroscopy

NASA Astrophysics Data System (ADS)

Long, Brittany E.; Betancur, Juan; Choi, Yoon Jeong; Cooke, S. A.; Grubbs, G. S., II; Ogulnick, Jonathan; Holmes, Tara

2017-06-01

Pure rotational spectra of the title molecules have been recorded using chirped pulse Fourier transform microwave spectroscopy. Under our experimental conditions only one conformer has been observed for each of the four compounds. These conformers have torsional angles of CXCC = 180^o, XCCC = 60^o, CCCC = 180^o, and, for the C_5H_{11}-X-CH_3 species, CCCC_{Methyl} = 180^o. These angles correspond to anti-gauche-anti conformations for the butyl methyl ether/thioether species, and anti-gauche-anti-anti conformations for the pentyl methyl ether/thioether species. Splittings due to the internal rotation of the X-CH_3 group are observed in both butyl species but are not observed in the pentyl species. The barrier to the X-CH_3 internal rotation has been investigated through spectral analyses and quantum chemical calculations. The differences in the internal rotation barrier between the ethers and thioethers will be discussed and will further be compared to the barriers obtained for similar molecules.

Probing the Electronic Environment of Methylindoles using Internal Rotation and (14)N Nuclear Quadrupole Coupling.

PubMed

Gurusinghe, Ranil M; Tubergen, Michael J

2016-05-26

High-resolution rotational spectra were recorded in the 10.5-21.0 GHz frequency range for seven singly methylated indoles. (14)N nuclear quadrupole hyperfine structure and spectral splittings arising from tunneling along the internal rotation of the methyl group were resolved for all indole species. The nuclear quadrupole coupling constants were used to characterize the electronic environment of the nitrogen atom, and the program XIAM was used to fit the barrier to internal rotation to the measured transition frequencies. The best fit barriers were found to be 277.1(2), 374.32(4), 414.(5), 331.6(2), 126.8675(15), 121.413(4), and 426(3) cm(-1) for 1-methylindole through 7-methylindole, respectively. The fitted barriers were found to be in good agreement with barriers calculated at the ωB97XD/6-311++G(d,p) level. The complete set of experimental barriers is compared to theoretical investigations of the origins of methyl torsional barriers and confirms that the magnitude of these barriers is an overall effect of individual hyperconjugative and structural interactions of many bonding/antibonding orbitals.

Rotary internal combustion engine with integrated supercharged fuel-air induction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Southard, A.A.

This patent describes an improved method of operating a rotary internal combustion engine of the type wherein a multicusped rotor rotatable upon a rotatable eccentric rotates within a cavity bounded by a wall of lobed trochoidal configuration. The rotor cusps have sealing engagement separating and defining operating chambers in the cavity about the rotor between adjacent pairs of cusps. Such chambers are angularly spaced about and orbit the center of the cavity as the rotor rotates while each chamber alternately expands and contracts in volume. The method comprises cylindrically operating each chamber through a sequence of six phases that aremore » synchronized with three successive increases and decreases in the volume of such chamber, with the first four phases being an internal combustion engine power cycle comprising an air intake phase, a compression phase, a combustion phase and an exhaust phase. The fifth phase comprises inducting air into the chamber, and the sixth phase comprises compressing the inducted air in such chamber and passing such inducted and compressed air through an elongated transfer zone.« less

International Space Station Alpha's bearing, motor, and roll ring module developmental testing and results

NASA Technical Reports Server (NTRS)

Obrien, David L.

1994-01-01

This paper presents the design and developmental testing associated with the bearing, motor, and roll ring module (BMRRM) used for the beta rotation axis on International Space Station Alpha (ISSA). The BMRRM with its controllers located in the electronic control unit (ECU), provides for the solar array pointing and tracking functions as well as power and signal transfer across a rotating interface.

Impact of Protected Sleep Period for Internal Medicine Interns on Overnight Call on Depression, Burnout, and Empathy

PubMed Central

Shea, Judy A.; Bellini, Lisa M.; Dinges, David F.; Curtis, Meredith L.; Tao, Yuanyuan; Zhu, Jingsan; Small, Dylan S.; Basner, Mathias; Norton, Laurie; Novak, Cristina; Dine, C. Jessica; Rosen, Ilene M.; Volpp, Kevin G.

2014-01-01

Background Patient safety and sleep experts advocate a protected sleep period for residents. Objective We examined whether interns scheduled for a protected sleep period during overnight call would have better end-of-rotation assessments of burnout, depression, and empathy scores compared with interns without protected sleep periods and whether the amount of sleep obtained during on call predicted end-of-rotation assessments. Methods We conducted a randomized, controlled trial with internal medicine interns at the Philadelphia Veterans Affairs Medical Center (PVAMC) and the Hospital of the University of Pennsylvania (HUP) in academic year 2009–2010. Four-week blocks were randomly assigned to either overnight call permitted under the 2003 duty hour standards or a protected sleep period from 12:30 am to 5:30 am. Participants wore wrist actigraphs. At the beginning and end of the rotations, they completed the Beck Depression Inventory (BDI-II), Maslach Burnout Inventory (MBI-HSS), and Interpersonal Reactivity Index (IRI). Results A total of 106 interns participated. There were no significant differences between groups in end-of-rotation BDI-II, MBI-HSS, or IRI scores at either location (P > .05). Amount of sleep while on call significantly predicted lower MBI-Emotional Exhaustion (P < .003), MBI-Depersonalization (P < .003), and IRI-Personal Distress (P < .006) at PVAMC, and higher IRI-Perspective Taking (P < .008) at HUP. Conclusions A protected sleep period produced few consistent improvements in depression, burnout, or empathy, although depression was already low at baseline. Possibly the amount of protected time was too small to affect these emotional states or sleep may not be directly related to these scores. PMID:24949128

Does a critical rotator cuff tear stage exist?: a biomechanical study of rotator cuff tear progression in human cadaver shoulders.

PubMed

Oh, Joo Han; Jun, Bong Jae; McGarry, Michelle H; Lee, Thay Q

2011-11-16

It is unknown at which stage of rotator cuff tear the biomechanical environment is altered. The purpose of this study was to determine if a critical rotator cuff tear stage exists that alters glenohumeral joint biomechanics throughout the rotational range of shoulder motion, and to evaluate the biomechanical effect of parascapular muscle-loading. Eight cadaver shoulders were used with a custom testing system. Four progressive rotator cuff tear stages were investigated on the basis of footprint anatomy. Three muscle-loading conditions were examined: rotator cuff only; rotator cuff with deltoid muscle; and rotator cuff, deltoid, pectoralis major, and latissimus dorsi muscles. Testing was performed in the scapular plane with 0°, 30°, and 60° of shoulder abduction. The maximum internal and external rotations were measured with 3.4 Nm of torque. The position of the humeral head apex with respect to the glenoid was calculated with use of a MicroScribe 3DLX digitizing system throughout the rotational range of motion. The abduction capability was determined as the abduction angle achieved with increasing deltoid load. Tear of the entire supraspinatus tendon significantly increased maximum external rotation and significantly decreased abduction capability with higher deltoid loads (p < 0.05). Tear of the entire supraspinatus tendon and half of the infraspinatus tendon significantly shifted the humeral head apex posteriorly at the midrange of rotation and superiorly at maximum internal rotation (p < 0.05). Loading the pectoralis major and latissimus dorsi muscles decreased the amount of humeral head elevation due to deltoid loading. Tear of the entire supraspinatus tendon was the critical stage for increasing rotational range of shoulder motion and for decreased abduction capability. Further tear progression to the infraspinatus muscle was the critical stage for significant changes in humeral head kinematics. The pectoralis major and latissimus dorsi muscles played an important role in stabilizing the humeral head as the rotator cuff tear progressed.

Humeral external rotation handling by using the Bobath concept approach affects trunk extensor muscles electromyography in children with cerebral palsy.

PubMed

Grazziotin Dos Santos, C; Pagnussat, Aline S; Simon, A S; Py, Rodrigo; Pinho, Alexandre Severo do; Wagner, Mário B

2014-10-20

This study aimed to investigate the electromyographic activity of cervical and trunk extensors muscles in children with cerebral palsy during two handlings according to the Bobath concept. A crossover trial involving 40 spastic diplegic children was conducted. Electromyography (EMG) was used to measure muscular activity at sitting position (SP), during shoulder internal rotation (IR) and shoulder external rotation (ER) handlings, which were performed using the elbow joint as key point of control. Muscle recordings were performed at the fourth cervical (C4) and at the tenth thoracic (T10) vertebral levels. The Gross Motor Function Classification System (GMFCS) was used to assess whether muscle activity would vary according to different levels of severity. Humeral ER handling induced an increase on EMG signal of trunk extensor muscles at the C4 (P=0.007) and T10 (P<0.001) vertebral levels. No significant effects were observed between SP and humeral IR handling at C4 level; However at T10 region, humeral IR handling induced an increase of EMG signal (P=0.019). Humeral ER resulted in an increase of EMG signal at both levels, suggesting increase of extensor muscle activation. Furthermore, the humeral ER handling caused different responses on EMG signal at T10 vertebra level, according to the GMFCS classification (P=0.017). In summary, an increase of EMG signal was observed during ER handling in both evaluated levels, suggesting an increase of muscle activation. These results indicate that humeral ER handling can be used for diplegic CP children rehabilitation to facilitate cervical and trunk extensor muscles activity in a GMFCS level-dependent manner. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exploring the properties of Solar Prominence Tornados

NASA Astrophysics Data System (ADS)

Ahmad, E.; Panesar, N. K.; Sterling, A. C.; Moore, R. L.

2015-12-01

Solar prominences consist of relatively cool and dense plasma embedded in the hotter solar corona above the solar limb. They form along magnetic polarity inversion lines, and are magnetically supported against gravity at heights of up to ~100 Mm above the chromosphere. Often, parts of prominences visually resemble Earth-based tornados, with inverted-cone-shaped structures and internal motions suggestive of rotation. These "prominence tornados" clearly possess complex magnetic structure, but it is still not certain whether they actually rotate around a ''rotation'' axis, or instead just appear to do so because of composite internal material motions such as counter-streaming flows or lateral (i.e. transverse to the field) oscillations. Here we study the structure and dynamics of five randomly selected prominences, using extreme ultraviolet (EUV) 171 Å images obtained with high spatial and temporal resolution by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) spacecraft. All of the prominences resided in non-active-region locations, and displayed what appeared to be tornado-like rotational motions. Our set includes examples oriented both broadside and end-on to our line-of-sight. We created time-distance plots of horizontal slices at several different heights of each prominence, to study the horizontal plasma motions. We observed patterns of oscillations at various heights in each prominence, and we measured parameters of these oscillations. We find the oscillation time periods to range over ~50 - 90 min, with average amplitudes of ~6,000 km, and with average velocities of ~7 kms-1. We found similar values for prominences viewed either broadside or end-on; this observed isotropy of the lateral oscillatory motion suggests that the apparent oscillations result from actual rotational plasma motions and/or lateral oscillations of the magnetic field, rather than to counter-streaming flows. This research was supported by the National Science Foundation under Grant No. AGS-1460767; EA participated in the Research Experience for Undergraduates (REU) program, at NASA/MSFC. Additional support was from a grant from the NASA LWS program.

Quality of Life, Sleep, and Health of Air Traffic Controllers With Rapid Counterclockwise Shift Rotation.

PubMed

Sonati, Jaqueline Girnos; De Martino, Milva Maria Figueiredo; Vilarta, Roberto; da Silva Maciel, Érika; Sonati, Renato José Ferreira; Paduan, Paulo Cézar

2016-08-01

Rotating shiftwork is common for air traffic controllers and usually causes sleep deprivation, biological adaptations, and life changes for these workers. This study assessed quality of life, the sleep, and the health of 30 air traffic controllers employed at an international airport in Brazil. The objective was to identify health and quality of life concerns of these professionals. The results identified physical inactivity, overweight, excess body fat, low scores for physical and social relationships, and sleep deprivation for workers in all four workshifts. In conclusion, these workers are at risk for chronic non-transmittable diseases and compromised work performance, suggesting the need for more rest time before working nightshifts and work environments that stimulate physical activity and healthy diets. © 2016 The Author(s).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munro, S.L.; Andrews, P.R.; Craik, D.J.

The solution dynamics of a series of clinically potent antidepressants have been investigated by measuring /sup 13/C NMR relaxation parameters. Correlation times and internal motional rates were calculated from spin-lattice relaxation times and nuclear Overhauser effects for the protonated carbons in mianserin, imipramine-like antidepressants, and amitriptyline-like antidepressants. These data were interpreted in terms of overall molecular tumbling, internal rotations, and inherent flexibility of these structures. Of particular interest was the conformational variability of the tricyclic nucleus of the tricyclic antidepressants, where the data indicated a fivefold difference in mobility of the dimethylene bridge of imipramine-like antidepressants relative to amitriptyline-like compounds.more » The implications of such a difference in internal motions is discussed in relation to previous NMR studies and to the reported differences in pharmacological activity of these antidepressants.« less

Comparison of fit accuracy and torque maintenance of zirconia and titanium abutments for internal tri-channel and external-hex implant connections

PubMed Central

Siadat, Hakimeh; Beyabanaki, Elaheh; Mousavi, Niloufar

2017-01-01

PURPOSE This in vitro study aimed to evaluate the effect of implant connection design (external vs. internal) on the fit discrepancy and torque loss of zirconia and titanium abutments. MATERIALS AND METHODS Two regular platform dental implants, one with external connection (Brånemark, Nobel Biocare AB) and the other with internal connection (Noble Replace, Nobel Biocare AB), were selected. Seven titanium and seven customized zirconia abutments were used for each connection design. Measurements of geometry, marginal discrepancy, and rotational freedom were done using video measuring machine. To measure the torque loss, each abutment was torqued to 35 Ncm and then opened by means of a digital torque wrench. Data were analyzed with two-way ANOVA and t-test at α=0.05 of significance. RESULTS There were significant differences in the geometrical measurements and rotational freedom between abutments of two connection groups (P<.001). Also, the results showed significant differences between titanium abutments of internal and external connection implants in terms of rotational freedom (P<.001). Not only customized internal abutments but also customized external abutments did not have the exact geometry of prefabricated abutments (P<.001). However, neither connection type (P=.15) nor abutment material (P=.38) affected torque loss. CONCLUSION Abutments with internal connection showed less rotational freedom. However, better marginal fit was observed in externally connected abutments. Also, customized abutments with either connection could not duplicate the exact geometry of their corresponding prefabricated abutment. However, neither abutment connection nor material affected torque loss values. PMID:28874994

The rotational spectrum of the water-hydroperoxy radical (H2O-HO2) complex.

PubMed

Suma, Kohsuke; Sumiyoshi, Yoshihiro; Endo, Yasuki

2006-03-03

Peroxy radicals and their derivatives are elusive but important intermediates in a wide range of oxidation processes. We observed pure rotational transitions of the water-hydroperoxy radical complex, H2O-HO2, in a supersonic jet by means of a Fourier transform microwave spectrometer combined with a double-resonance technique. The observed rotational transitions were found to split into two components because of the internal rotation of the water moiety. The molecular constants for the two components were determined precisely, supporting a molecular structure in which HO2 acts as a proton donor to form a nearly planar five-membered ring, and one hydrogen atom of water sticks out from the ring plane. The structure and the spectral splittings due to internal rotation provide information on the nature of the bonding interaction between open- and closed-shell species, and they also provide accurate transition frequencies that are applicable to remote sensing of this complex, which may elucidate its potential roles in atmospheric and combustion chemistry.

Reverse shoulder arthroplasty leads to significant biomechanical changes in the remaining rotator cuff.

PubMed

Herrmann, Sebastian; König, Christian; Heller, Markus; Perka, Carsten; Greiner, Stefan

2011-08-16

After reverse shoulder arthroplasty (RSA) external and internal rotation will often remain restricted. A postoperative alteration of the biomechanics in the remaining cuff is discussed as a contributing factor to these functional deficits. In this study, muscle moment arms as well as origin-to-insertion distance (OID) were calculated using three-dimensional models of the shoulder derived from CT scans of seven cadaveric specimens. Moment arms for humeral rotation are significantly smaller for the cranial segments of SSC and all segments of TMIN in abduction angles of 30 degrees and above (p ≤ 0.05). Abduction moment arms were significantly decreased for all segments (p ≤ 0.002). OID was significantly smaller for all muscles at the 15 degree position (p ≤ 0.005), apart from the cranial SSC segment. Reduced rotational moment arms in conjunction with the decrease of OID may be a possible explanation for the clinically observed impaired external and internal rotation.

Coarsening dynamics of binary liquids with active rotation.

PubMed

Sabrina, Syeda; Spellings, Matthew; Glotzer, Sharon C; Bishop, Kyle J M

2015-11-21

Active matter comprised of many self-driven units can exhibit emergent collective behaviors such as pattern formation and phase separation in both biological (e.g., mussel beds) and synthetic (e.g., colloidal swimmers) systems. While these behaviors are increasingly well understood for ensembles of linearly self-propelled "particles", less is known about the collective behaviors of active rotating particles where energy input at the particle level gives rise to rotational particle motion. A recent simulation study revealed that active rotation can induce phase separation in mixtures of counter-rotating particles in 2D. In contrast to that of linearly self-propelled particles, the phase separation of counter-rotating fluids is accompanied by steady convective flows that originate at the fluid-fluid interface. Here, we investigate the influence of these flows on the coarsening dynamics of actively rotating binary liquids using a phenomenological, hydrodynamic model that combines a Cahn-Hilliard equation for the fluid composition with a Navier-Stokes equation for the fluid velocity. The effect of active rotation is introduced though an additional force within the Navier-Stokes equations that arises due to gradients in the concentrations of clockwise and counter-clockwise rotating particles. Depending on the strength of active rotation and that of frictional interactions with the stationary surroundings, we observe and explain new dynamical behaviors such as "active coarsening" via self-generated flows as well as the emergence of self-propelled "vortex doublets". We confirm that many of the qualitative behaviors identified by the continuum model can also be found in discrete, particle-based simulations of actively rotating liquids. Our results highlight further opportunities for achieving complex dissipative structures in active materials subject to distributed actuation.

Electronic spectra of 2- and 3-tolunitrile in the gas phase. I. A study of methyl group internal rotation via rovibronically resolved spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruiz-Santoyo, José Arturo; Álvarez-Valtierra, Leonardo, E-mail: leoav@fisica.ugto.mx; Wilke, Josefin

2016-01-28

Rotationally resolved fluorescence excitation spectra of the origin bands in the S{sub 1}←S{sub 0} transition of 2-tolunitrile (2TN) and 3-tolunitrile (3TN) have been recorded in the collision-free environment of a molecular beam. Analyses of these data provide the rotational constants of each molecule and the potential energy curves governing the internal rotation of the attached methyl groups in both electronic states. 2TN exhibits much larger barriers along this coordinate than 3TN. Interestingly, the electronic transition dipole moment in both molecules is markedly influenced by the position of the attached methyl group rather than the position of the cyano group; possiblemore » reasons for this intriguing behavior are discussed.« less

A Three-dimensional Non-spherical Calculation Of The Rotationally Distorted Shape And Internal Structure Of A Model Of Jupiter With A Polytropic Index Of Unity

NASA Astrophysics Data System (ADS)

Zhang, Keke; Kong, D.; Schubert, G.; Anderson, J.

2012-10-01

An accurate calculation of the rotationally distorted shape and internal structure of Jupiter is required to understand the high-precision gravitational field that will be measured by the Juno spacecraft now on its way to Jupiter. We present a three-dimensional non-spherical numerical calculation of the shape and internal structure of a model of Jupiter with a polytropic index of unity. The calculation is based on a finite element method and accounts for the full effects of rotation. After validating the numerical approach against the asymptotic solution of Chandrasekhar (1933) that is valid only for a slowly rotating gaseous planet, we apply it to a model of Jupiter whose rapid rotation causes a significant departure from spherical geometry. The two-dimensional distribution of the density and the pressure within Jupiter is then determined via a hybrid inverse approach by matching the a priori unknown coefficient in the equation of state to the observed shape of Jupiter. After obtaining the two-dimensional distribution of Jupiter's density, we then compute the zonal gravity coefficients and the total mass from the non-spherical Jupiter model that takes full account of rotation-induced shape changes. Our non-spherical model with a polytrope of unit index is able to produce the known mass and zonal gravitational coefficients of Jupiter. Chandrasekhar, S. 1933, The equilibrium of distorted polytropes, MNRAS 93, 390

Effects of hand grip exercise on shoulder joint internal rotation and external rotation peak torque.

PubMed

Lee, Dong-Rour; Jong-Soon Kim, Laurentius

2016-08-10

The goal of this study is to analyze the effects of hand grip training on shoulder joint internal rotation (IR)/external rotation (ER) peak torque for healthy people. The research was conducted on 23 healthy adults in their 20 s-30 s who volunteered to participate in the experiment. Hand grip power test was performed on both hands of the research subjects before/after the test to study changes in hand grip power. Isokinetic machine was used to measure the concentric IRPT (internal rotation peak torque) and concentric ERPT (external rotation peak torque) at the velocity of 60°/sec, 90°/sec, and 180°/sec before/after the test. Hand grip training was performed daily on the subject's right hand only for four weeks according to exercise program. Finally, hand grip power of both hands and the maximum torque values of shoulder joint IR/ER were measured before/after the test and analyzed. There was a statistically significant difference in the hand grip power of the right hand, which was subject to hand grip training, after the experiment. Also, statistically significant difference for shoulder ERPT was found at 60°/sec. Hand grip training has a positive effect on shoulder joint IRPT/ERPT and therefore can help strengthen muscles around the shoulder without using weight on the shoulder. Consequently, hand grip training would help maintain strengthen the muscles around the shoulder in the early phase of rehabilitation process after shoulder surgery.

A study of safety and tolerability of rotatory vestibular input for preschool children

PubMed Central

Su, Wen-Ching; Lin, Chin-Kai; Chang, Shih-Chung

2015-01-01

The objectives of this study were to determine a safe rotatory vestibular stimulation input for preschool children and to study the effects of grade level and sex of preschool children during active, passive, clockwise, and counterclockwise rotation vestibular input. This study adopted purposive sampling with 120 children from three kindergarten levels (K1, K2, and K3) in Taiwan. The subjects ranged in age from 46 to 79 months of age (mean: 62.1 months; standard deviation =9.60). This study included testing with four types of vestibular rotations. The number, duration, and speed of rotations were recorded. The study found that the mean number of active rotations was 10.28; the mean duration of rotation was 24.17 seconds; and the mean speed was 2.29 seconds per rotation. The mean number of passive rotations was 23.04. The differences in number of rotations in clockwise, counterclockwise, active, and passive rotations were not statistically significant. Sex and grade level were not important related factors in the speed and time of active rotation. Different sexes, rotation methods (active, passive), and grades made significant differences in the number of rotations. The safety and tolerability of rotatory vestibular stimulation input data obtained in this study can provide useful reference data for therapists using sensory integration therapy. PMID:25657579

Gender differences in muscular protection of the knee in torsion in size-matched athletes.

PubMed

Wojtys, Edward M; Huston, Laura J; Schock, Harold J; Boylan, James P; Ashton-Miller, James A

2003-05-01

Female athletes who participate in sports involving jumping and cutting maneuvers are up to eight times more likely to sustain a rupture of the anterior cruciate ligament than are men participating in the same sports. We tested the hypothesis that healthy young women are able to volitionally increase the apparent torsional stiffness of the knee, by maximally activating the knee muscles, significantly less than are size-matched men participating in the same type of sport. Twenty-four NCAA (National Collegiate Athletic Association) Division-I athletes (twelve men and twelve women) competing in sports associated with a high risk of injury to the anterior cruciate ligament (basketball, volleyball, and soccer) were compared with twenty-eight collegiate endurance athletes (fourteen men and fourteen women) participating in sports associated with a low risk of such injuries (bicycling, crew, and running). Male and female pairs were matched for age, height, weight, body mass index, shoe size, and activity level. Testing was performed with a weighted pendulum that applied a medially directed 80-N impulse force to the lateral aspect of the right forefoot. The resulting internal rotation of the leg was measured optically, to the nearest 0.25 degrees, at 30 degrees and 60 degrees of knee flexion, both with and without maximal activation of the knee muscles. Maximal rotations of the leg were greater in women than in men in both the passive and the active muscle state (16% and 27% greater [p = 0.01 and p = 0.02], respectively). Moreover, female athletes exhibited a significantly (18%) smaller volitional increase in apparent torsional stiffness of the knee under internal rotation loading than did the matched male athletes (p = 0.014); this was particularly the case for those who participated in sports involving jumping and pivoting maneuvers (42% difference between genders, p = 0.001). The collegiate female athletes involved in high-risk sports exhibited less muscular protection of the knee ligaments during external loading of the knee than did size and sport-matched male athletes.

Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome. A prospective randomized double-blind study.

PubMed

Everts, P A; Devilee, R J J; Brown Mahoney, C; van Erp, A; Oosterbos, C J M; Stellenboom, M; Knape, J T A; van Zundert, A

2008-01-01

Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). PLG was produced from platelet-leukocyte-rich plasma (P-LRP), prepared from a unit of whole blood. Forty patients were included in the study. Self-assessed evaluations, using the American Shoulder and Elbow Surgeons scoring system of activities of daily living (ADL), joint instability, pain levels, pain medications, and clinical evaluations for range of motion were conducted. Platelet and leukocyte counts were significantly increased in the P-LRP compared to baseline counts. Treated patients demonstrated decreased visual analog scales for pain and used significantly less pain medication, had an improved range of motion during passive forward elevation, external rotation, external rotation with arm at 90 degrees abduction, internal rotation, and cross body adduction compared to control patients (p < 0.001). No differences in the instability score were observed between the groups. Furthermore, treated patients performed more ADL (p < 0.05). In the PLG-treated group, recovery was faster and patients returned earlier to daily activities and also took less pain medication than control subjects. Copyright 2008 S. Karger AG, Basel.

Sex differences in coupled knee motions during the transition from non-weight bearing to weight bearing.

PubMed

Shultz, Sandra J; Beynnon, Bruce D; Schmitz, Randy J

2009-06-01

Knee ligament injuries frequently happen when the joint transitions from non-weight bearing (NWB) to weight bearing (WB). To gain insight into the mechanism that produces these injuries, physically active females (N = 41) and males (N = 39) underwent measurement of coupled tibiofemoral joint displacements [anterior tibial translation (ATT) and varus-valgus and internal-external rotations] and neuromuscular responses as the knee transitioned from NWB to WB in response to a 40% body weight load applied under the control of gravity. The transition from NWB to WB produced no difference in ATT between males and females; however, significant sex-based differences were noted for both transverse and frontal plane knee motions. With the knee NWB, females were in a greater absolute valgus compared to males (6.6 vs. 5.0 degrees), and moved through greater varus motion than males during the transition from NW to WB (2.3 vs. 1.4 degrees), resulting in similar valgus alignment for both sexes at peak WB (4.3 vs. 3.6 degrees). In the transverse plane, the knees of females were positioned in more external rotation compared to males when NWB (1.4 vs. -0.3 degrees), then females externally rotated their knees while males internally rotated their knees during the transition from NWB to WB. This resulted in a 3.4 degrees difference in transverse plane knee position at peak WB (2.3 vs. -1.1 degrees). Our findings suggest that the coupled knee motions produced during the transition from NWB to WB are sex dependent, and may provide insight into the knee motion patterns that place females at increased risk of knee ligament injury. Copyright 2008 Orthopaedic Research Society

Use of botulinum toxin type A in the management of neonatal brachial plexus palsy.

PubMed

Michaud, Linda J; Louden, Emily J; Lippert, William C; Allgier, Allison J; Foad, Susan L; Mehlman, Charles T

2014-12-01

To evaluate functional outcomes and the impact on surgical interventions after the use of botulinum neurotoxin type A (BoNT-A) for muscle imbalance, cocontractions, or contractures with neonatal brachial plexus palsy. A retrospective cohort study. A brachial plexus center in a tertiary children's hospital. Fifty-nine patients with neonatal brachial plexus palsy (75 injection procedures, 91 muscles and/or muscle groups) received BoNT-A injections (mean age at injection, 36.2 months; range, 6-123 months; 31 boys; 30 right-sided injuries, 28 left-sided injuries, 1 bilateral injury). Data collected retrospectively from medical records, from procedure notes and clinic visits before BoNT-A use, at ≤6 months follow-up (BoNT-A active [BA]) and at ≥7 months follow-up (BoNT-A not active [BNA]) included demographics, injection indication, side, and site(s), previous surgical history, occupational therapy and/or physical therapy plan, and outcome measurements. Outcomes assessed before and after injections included active and passive range of motion, Mallet and Toronto scores, parent comments about arm function, preinjection surgical considerations, and postinjection surgical history. Injection procedures included 51 to shoulder internal rotators, 15 triceps, 15 pronator teres, 9 biceps, and 1 flexor carpi ulnaris. Active and passive shoulder external rotation (SER) range of motion improved after shoulder internal rotator injections (P = .0003 and P = .002, respectively), as did Mallet scores with BA; the latter were sustained with BNA. Surgical intervention was averted, modified, or deferred after BoNT-A in 45% (n = 20) under surgical consideration before BoNT-A. Active elbow flexion improved in 67% (P = .005), sustained BNA (P = .004) after triceps injections; 2 of 7 patients averted surgery. Active supination improved with BA (P = .002), with gains sustained BNA (P = .016). Passive elbow extension improved after biceps injections by an average 17° (P = .004) BA, although not sustained BNA. BoNT-A is an effective adjunct to therapy and surgery in managing muscle imbalance, cocontractions, and contractures in neonatal brachial plexus palsy. Use of BoNT-A can result in averting, modifying, or deferring surgical interventions in a number of affected children. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

The effect of trunk rotation during shoulder exercises on the activity of the scapular muscle and scapular kinematics.

PubMed

Yamauchi, Taishi; Hasegawa, Satoshi; Matsumura, Aoi; Nakamura, Masatoshi; Ibuki, Satoko; Ichihashi, Noriaki

2015-06-01

In patients with shoulder disease, kinetic chain exercises including hip or trunk movement are recommended. However, the actual muscle activation and scapular kinematics of these exercises are not known. The purpose of this study was to examine the effect of trunk rotation on shoulder exercises that are devised to improve scapular function. Thirteen healthy young men participated in this study. Scaption, external rotation in the first and second positions, and prone scapular retraction at 45°, 90°, and 145° of shoulder abduction were performed with and without trunk rotation. Electromyography was used to assess the scapular muscle activity of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA), and electromagnetic motion capture was used to assess scapular motion. The muscle activity ratio, which is the activity of the UT to the MT, LT, and SA, was calculated. These data were compared between 2 conditions (with and without trunk rotation) for each exercise. Adding trunk rotation to scaption, the first external rotation, and the second external rotation significantly increased scapular external rotation and posterior tilt, and all 3 exercises increased LT activation. In addition, trunk rotation with scapular retraction at 90° and 145° of shoulder abduction significantly decreased the UT/LT ratio. Our findings suggest that shoulder exercises with trunk rotation in this study may be effective in patients who have difficulty in enhancing LT activity and suppressing excessive activation of the UT or in cases in which a decreased scapular external rotation or posterior tilt is observed. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Influence of Body Position on Shoulder and Trunk Muscle Activation During Resisted Isometric Shoulder External Rotation.

PubMed

Krause, David A; Dueffert, Lucas G; Postma, Jaclyn L; Vogler, Eric T; Walsh, Amy J; Hollman, John H

External rotation (ER) strengthening of the shoulder is an integral component of rehabilitative and preventative programs for overhead athletes. A variety of shoulder ER strengthening exercises are reported, including those intended to integrate the core musculature. The purpose of this study was to examine ER torque and electromyographic (EMG) activation of shoulder and trunk muscles while performing resisted isometric shoulder ER in 3 positions (standing, side lying, and side plank). Significantly greater force and shoulder muscle activation would be generated while side lying given the inherent stability of the position, and greater trunk muscle activation would be generated in the less stable plank position. Quasi-experimental repeated-measures study. Level 5. A convenience sample of 25 healthy overhead recreational athletes (9 men, 16 women) participated in this study. EMG electrodes were placed on the infraspinatus, posterior deltoid, middle trapezius, multifidi, internal obliques, and external obliques. EMG signals were normalized to a maximal isometric contraction. Participants performed resisted isometric ER in standing, side-lying, and side plank positions. Results were analyzed using a repeated-measures analysis of variance with post hoc Bonferroni corrections (α = 0.05). There was no significant difference in ER torque between positions (α = 0.05). A significant difference in EMG activity of shoulder and trunk musculature between positions was found in 7 of the 8 muscles monitored. Significantly greater EMG activity in the infraspinatus, middle trapezius, and the nondominant external and internal obliques was found in the side plank position as compared with standing and side lying. While there was no difference in ER torque between the 3 exercise positions, EMG activity of the shoulder and trunk muscles was dependent on body position. If a clinician is seeking to integrate trunk muscle activation while performing shoulder ER strengthening, the side plank position is preferred as compared with standing or side lying.

International Space Station Earth Observations Working Group

NASA Technical Reports Server (NTRS)

Stefanov, William L.; Oikawa, Koki

2015-01-01

The multilateral Earth Observations Working Group (EOWG) was chartered in May 2012 in order to improve coordination and collaboration of Earth observing payloads, research, and applications on the International Space Station (ISS). The EOWG derives its authority from the ISS Program Science Forum, and a NASA representative serves as a permanent co-chair. A rotating co-chair position can be occupied by any of the international partners, following concurrence by the other partners; a JAXA representative is the current co-chair. Primary functions of the EOWG include, 1) the exchange of information on plans for payloads, from science and application objectives to instrument development, data collection, distribution and research; 2) recognition and facilitation of opportunities for international collaboration in order to optimize benefits from different instruments; and 3) provide a formal ISS Program interface for collection and application of remotely sensed data collected in response to natural disasters through the International Charter, Space and Major Disasters. Recent examples of EOWG activities include coordination of bilateral data sharing protocols between NASA and TsNIIMash for use of crew time and instruments in support of ATV5 reentry imaging activities; discussion of continued use and support of the Nightpod camera mount system by NASA and ESA; and review and revision of international partner contributions on Earth observations to the ISS Program Benefits to Humanity publication.

Effects of perturbation or plyometric training on core control and knee joint loading in women during lateral movements.

PubMed

Weltin, E; Gollhofer, A; Mornieux, G

2017-03-01

Deficits in trunk control are argued to increase the risk of knee injuries. However, no existing training program effectively addresses trunk control during lateral movements, such as cutting maneuvers. The purpose of this study was to investigate whether a combination of perturbation and plyometric training (PPT) would reduce trunk excursions against the new movement direction and reduce knee joint moments during lateral movements. Twenty-four active women participated in a RCT, where trunk and pelvis kinematics and knee joint moments were measured during lateral reactive jumps (LRJ) and unanticipated cutting maneuvers before and after a 4-week PPT program and compared to a control group. During LRJ, trunk rotation away from the new movement direction was reduced (P < 0.001), while pelvis rotation toward the new direction was increased (P = 0.006) after PPT. Moreover, decreased knee extension moments (P = 0.028) and knee internal rotation moments (P < 0.001) were reported after both trainings. Additionally, PPT reduced trunk rotation by 7.2° during unanticipated cuttings. A 4-week PPT improved core control by reducing trunk rotation and reduced knee joint moments during LRJ. During training, perturbations should be introduced to improve core control during dynamic athletic movements, possibly reducing the risk of ACL injuries. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Posterior capsular fibrosis in professional baseball pitchers: case series of MR arthrographic findings in six patients with glenohumeral internal rotational deficit.

PubMed

Tehranzadeh, Arash D; Fronek, Jan; Resnick, Donald

2007-01-01

In the high-performance athlete, acquired thickening of the posterior joint capsule is a proposed etiology for glenohumeral internal rotational deficit (GIRD). The purpose of this study was to present our MR arthrographic imaging observations of posterior capsular thickening in professional baseball players who present with reduced throwing velocity related to pain and clinical findings of internal rotational deficit of the glenohumeral joint. Our observations of MR imaging features in patients with clinical and arthroscopic manifestations of GIRD lesions include articular surface partial thickness tears of the supraspinatus and infraspinatus tendons, superoposterior subluxation of the humeral head and SLAP tears of the labrum. Although no empiric standard currently exists for the axial dimension thickness of the shoulder capsule, we have observed a thickened appearance of the posterior band of the inferior glenohumeral ligament in these patients.

Two-dimensional planning can result in internal rotation of the femoral component in total knee arthroplasty.

PubMed

Okamoto, Shigetoshi; Mizu-uchi, Hideki; Okazaki, Ken; Hamai, Satoshi; Tashiro, Yasutaka; Nakahara, Hiroyuki; Iwamoto, Yukihide

2016-01-01

The first purpose of this study was to compare the reproducibility of two-dimensional (2D) and three-dimensional (3D) measurements for preoperative planning of the femoral side in total knee arthroplasty (TKA). The second purpose was to evaluate the factors affecting the differences between the 2D and 3D measurements. Two-dimensional and 3D measurements for preoperative planning of the femoral side in TKA were evaluated in 75 varus knees with osteoarthritis. The femoral valgus angle, defined as the angle between the mechanical and anatomical axes of the femur, and the clinical rotation angle and surgical rotation angle, defined by the angles between the posterior condylar line and the clinical or surgical transepicondylar axes, respectively, were analysed using 2D (radiographs and axial CT slices) and 3D (3D bone models reconstructed from CT images) measurements. For all variables, 3D measurements were more reliable and reproducible than 2D measurements. The medians and ranges of the clinical rotation angle and surgical rotation angle were 6.6° (-1.7° to 12.1°) and 2.3° (-2.5° to 8.6°) in 2D, and 7.1° (2.7° to 11.4°) and 3.0° (-2.0° to 7.5°) in 3D. Varus/valgus alteration of the CT scanning direction relative to the mechanical axis affected the difference in clinical rotation angles between 2D and 3D measurements. Significantly, smaller values of the clinical rotation angle and surgical rotation angle were obtained by 2D compared to 3D measurements, which could result in internal rotation of the femoral component even if the surgeon performs the bone cutting precisely. Regarding clinical relevance, first, this study confirmed the reliability of 3D measurements. Second, it underscored the risk of internal rotation of the femoral component when using 2D measurement, even with precise bone cutting technique. These results will help surgeons avoid malpositioning of the femoral component if 2D measurements are used for preoperative planning in TKA. Prospective comparative study, Level Ш.

Adaptive changes in the dominant shoulders of female professional overhead athletes: mutual association and relation to shoulder injury.

PubMed

Tonin, Katarina; Stražar, Klemen; Burger, Helena; Vidmar, Gaj

2013-09-01

The aim of our study was to evaluate adaptive changes in the dominant shoulders of female professional overhead athletes, their mutual association, and relation between adaptive changes and shoulder injury. Thirty-six female professional volleyball and handball players were divided into two groups: 14 athletes were included in the symptomatic group (positive shoulder injury history and specific shoulder tests) and 22 athletes were included in the asymptomatic group (negative shoulder injury history and specific shoulder tests). Clinical examinations with specific shoulder tests, evaluation of rotational mobility, and symptoms of malposition and dyskinesis of the dominant scapula (SICK scapula syndrome) were performed. Glenohumeral rotators were isokinetically tested at 60 and 150°/s, with evaluation of stability ratios and rotator fatigability. On average, the participants had decreased internal rotation (P<0.001) and increased external rotation (P<0.001), lower spiking (P<0.01 at 60 and 150°/s) and conventional ratios (P≤0.01 at 60 and 150°/s), lower eccentric external rotator peak torques (eER) (P≤0.05 at 60 and 150°/s), and marginally lower eccentric internal rotator peak torques at 60°/s (P=0.061) on the dominant side compared with the nondominant side. The symptomatic group showed decreased ER (P=0.021), higher deficit of dominant eER at 60°/s (P=0.049), and higher fatigability of internal (P=0.013) and external rotators (P=0.028). The athletes with increased ER had more scapular lateralization (ρ=0.340, P=0.042), higher spiking ratios at 60°/s (ρ=0.349, P=0.037) and 150°/s (ρ=0.330, P=0.049), and lower cocking ratios at 60°/s (ρ=-0.477, P=0.003). Decreased dominant ER, higher deficit of dominant eccentric ER peak torques, and higher dominant rotator fatigability correlate with previous shoulder pain/injury. Different adaptive changes (rotational mobility, SICK scapula signs, and glenohumeral muscular imbalance) are inter-related. As a form of both prevention and rehabilitation for the athletes at risk, we recommend individually adjusted shoulder training on the basis of clinical and isokinetic testing.

Modeling the vestibulo-ocular reflex of the squirrel monkey during eccentric rotation and roll tilt

NASA Technical Reports Server (NTRS)

Merfeld, D. M.; Paloski, W. H. (Principal Investigator)

1995-01-01

Model simulations of the squirrel monkey vestibulo-ocular reflex (VOR) are presented for two motion paradigms: constant velocity eccentric rotation and roll tilt about a naso-occipital axis. The model represents the implementation of three hypotheses: the "internal model" hypothesis, the "gravito-inertial force (GIF) resolution" hypothesis, and the "compensatory VOR" hypothesis. The internal model hypothesis is based on the idea that the nervous system knows the dynamics of the sensory systems and implements this knowledge as an internal dynamic model. The GIF resolution hypothesis is based on the idea that the nervous system knows that gravity minus linear acceleration equals GIF and implements this knowledge by resolving the otolith measurement of GIF into central estimates of gravity and linear acceleration, such that the central estimate of gravity minus the central estimate of acceleration equals the otolith measurement of GIF. The compensatory VOR hypothesis is based on the idea that the VOR compensates for the central estimates of angular velocity and linear velocity, which sum in a near-linear manner. During constant velocity eccentric rotation, the model correctly predicts that: (1) the peak horizontal response is greater while "facing-motion" than with "back-to-motion"; (2) the axis of eye rotation shifts toward alignment with GIF; and (3) a continuous vertical response, slow phase downward, exists prior to deceleration. The model also correctly predicts that a torsional response during the roll rotation is the only velocity response observed during roll rotations about a naso-occipital axis. The success of this model in predicting the observed experimental responses suggests that the model captures the essence of the complex sensory interactions engendered by eccentric rotation and roll tilt.

STS-97 Crew Activity Report/Flight Day 10 Highlights

NASA Technical Reports Server (NTRS)

2000-01-01

On this tenth day of the STS-97 mission, Commander Brent W. Jett, Pilot Michael J. Bloomfield, and Mission Specialists Joseph R. Tanner, Carlos I. Noriega, and Marc Garneau are seen saying good-bye to the International Space Station's (ISS's) resident crew (Commander Bill Shepherd, Pilot Yuri Gidzenko and Flight Engineer Sergei Krikalev) and sealing the hatches between the Endeavour Orbiter and the ISS. Footage shows the ISS against a rotating Earth as it passes over China.

The Global Geophysical Fluids Center of IERS (and its Special Bureau for Mantle)

NASA Astrophysics Data System (ADS)

Chao, B. F.

2002-12-01

The Global Geophysical Fluids Center (GGFC) was established by the International Earth Rotation Service (IERS) on IERS's 10th anniversary day January 1, 1998, in an effort to expand IERS's services to the scientific community. Under the GGFC, eight Special Bureaus (SB) have been selected, each to be responsible for research and data service activities pertaining to mass transports and related geophysical processes in specific components of the Earth system, or "global geophysical fluids," including the atmosphere, oceans, solid Earth, core, and geophysical processes of gravity, loading, tides and hydrological cycles. GGFC and the SBs have the responsibility of supporting, facilitating, and providing services to the worldwide research community, in areas related to the variations in Earth rotation, gravity field and geocenter that are caused by mass transport in the global geophysical fluids. These minute variations have been observed by various space geodetic techniques, as effective remote sensing tools, with ever increasing precision/accuracy and temporal/spatial resolution. The GGFC and SBs have organized dedicated workshops and special sessions at international conferences, published articles, and held regular business meetings. The SBs maintain individual website for data services and information exchanges. See URL bowie.gsfc.nasa.gov/ggfc/. In particular, the SB for Mantle focuses on large-scale mass redistributions that occur in the mantle in association with various dynamic processes, including seismic activities, the post-glacial rebound, and mantle convections.

Internal rotation of the sun

NASA Technical Reports Server (NTRS)

Duvall, T. L., Jr.; Dziembowski, W. A.; Goode, P. R.; Gough, D. O.; Harvey, J. W.; Leibacher, J. W.

1984-01-01

The frequency difference between prograde and retrograde sectoral solar oscillations is analyzed to determine the rotation rate of the solar interior, assuming no latitudinal dependence. Much of the solar interior rotates slightly less rapidly than the surface, while the innermost part apparently rotates more rapidly. The resulting solar gravitational quadrupole moment is J2 = (1.7 + or - 0.4) x 10 to the -7th and provides a negligible contribution to current planetary tests of Einstein's theory of general relativity.

Evaluation of rotator cuff muscle strength in healthy individuals

PubMed Central

Cortez, Paulo José Oliveira; Tomazini, José Elias

2015-01-01

OBJECTIVE: To compare the strength generated by the rotator muscles of the shoulder joint between the right upper limb and left upper limb among healthy individuals. METHODS: To evaluate the muscle strength of upper limbs from isometric contractions in the horizontal direction (rotation) an isometric dynamometer was used, equipped with transducers, signal conditioning, a data acquisition board, and finally, a computer. Study participants were 22 male military subjects, aged between 18 and 19 years old, body mass between 57.7 and 93.0 kg (71.8 ± 9.45 kg) and height between 1.67 and 1.90 m (1.75 ± 0.06 m), healthy and without clinical diseases or any type of orthopedic injury in the muscle skeletal system. RESULTS: The internal rotation in the right upper limb (RUL) was higher than the average strength of internal rotation in the left upper limb (LUL) (p = 0.723). The external rotation strength in RUL was lower than the average strength of external rotation in the LUL (p=0.788). No statistical difference was observed by comparing the strength values of all isometric strength tests. CONCLUSION: For the sample and methodology used to assess muscle strength, there was no statistical difference between the strength generated by the muscles of the rotator cuff of the right and left upper limbs. Experimental Study. PMID:26207091

Simulation of Non-resonant Internal Kink Mode with Toroidal Rotation in NSTX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Guoyong

2013-07-16

Plasmas in spherical and conventional tokamaks, with weakly reversed shear q pro le and minimum q above but close to unity, are susceptible to an non-resonant (m, n ) = (1, 1) internal kink mode. This mode can saturate and persist and can induce a (2; 1) seed island for Neoclassical Tearing Mode (NTMs)1 . The mode can also lead to large energetic particle transport and signi cant broadening of beam-driven current. Motivated by these important e ects, we have carried out extensive nonlinear simulations of the mode with nite toroidal rotation using parameters and pro les of an NTSXmore » plasma with a weakly reversed shear pro le. The numerical results show that, at the experimental level, plasma rotation has little e ect on either equilibrium or linear stability. However, rotation can signi cantly inuence the nonlinear dynamics of the (1, 1) mode and the the induced (2, 1) magnetic island. The simulation results show that a rotating helical equilibrium is formed and maintained in the nonlinear phase at nite plasma rotation. In contrast, for non-rotating cases, the nonlinear evolution exhibits dynamic oscillations between a quasi-2D state and a helical state. Furthermore, the e ects of rotation are found to greatly suppress the (2, 1) magnetic island even at a low level.« less

Lumbar lordosis angle and trunk and lower-limb electromyographic activity comparison in hip neutral position and external rotation during back squats.

PubMed

Oshikawa, Tomoki; Morimoto, Yasuhiro; Kaneoka, Koji

2018-03-01

[Purpose] To compare the lumbar lordosis angle and electromyographic activities of the trunk and lower-limb muscles in the hip neutral position and external rotation during back squats. [Subjects and Methods] Ten healthy males without severe low back pain or lower-limb injury participated in this study. The lumbar lordosis angle and electromyographic activities were measured using three-dimensional motion-capture systems and surface electrodes during four back squats: parallel back squats in the hip neutral position and external rotation and full back squats in the hip neutral position and external rotation. A paired t-test was used to compare parallel and full back squats measurements in the hip neutral position and external rotation, respectively. [Results] During parallel back squats, the average lumbar lordosis angle was significantly larger in hip external rotation than in the hip neutral position. During full back squats, lumbar erector spinae and multifidus activities were significantly lower in hip external rotation than in the hip neutral position, whereas gluteus maximus activity was significantly higher in hip external rotation than in the hip neutral position. [Conclusion] The back squat in hip external rotation induced improvement of lumbar kyphosis, an increasing of the gluteus maximus activity and a decrease of both lumbar erector spinae and multifidus activities.

Glenohumeral Internal Rotation Deficit and Injuries: A Systematic Review and Meta-analysis

PubMed Central

Johnson, Jordan E.; Fullmer, Joshua A.; Nielsen, Chaseton M.; Johnson, Joshua K.; Moorman, Claude T.

2018-01-01

Background: There is an association between throwing activity and glenohumeral internal rotation deficit (GIRD). An 18° to 20° deficit has been adopted as the standard definition of pathological GIRD, but specific findings as to how GIRD relates to an injury are inconsistent. Purpose: To systematically review the literature to clarify the definition of GIRD diagnosis for adolescent and adult overhead athletes and to examine the association between GIRD and an increased risk of injuries in these athletes. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed. Observational studies comparing glenohumeral internal rotation range of motion (ROM) in injured and uninjured overhead athletes were included for the meta-analysis. Studies of adolescent and adult athletes were analyzed separately. ROM was compared for the injured and uninjured groups, and a weighted mean GIRD was estimated. To account for potential heterogeneity across studies, both fixed- and random-effects models were used to calculate a standardized mean difference (SMD). Results: Nine studies of level 3 or 4 evidence were included. From these, 12 study groups (4 adolescent, 8 adult) comprising 819 overhead athletes (226 injured, 593 uninjured) were included in the meta-analysis. The estimated SMD in GIRD between the injured and uninjured groups was 0.46 (95% CI, 0.15-0.77; P < .01) for the overall sample. The between-group effect was larger for adults (SMD, 0.60 [95% CI, 0.18 to 1.02]; P < .01) than adolescents (SMD, 0.20 [95% CI, –0.24 to 0.63]; P = .13). The weighted mean GIRD for the injured and uninjured groups was 13.8° ± 5.6° and 9.6° ± 3.0°, respectively, which also differed by age group. Moderate study heterogeneity was observed (I 2 = 69.0%). Conclusion: Based on this systematic review, the current definition of pathological GIRD may be too conservative, and a distinct definition may be required for adolescent and adult athletes. While the results indicate a link between internal rotation deficits and upper extremity injuries in the overhead athlete, higher quality prospective research is needed to clarify the role that GIRD plays in future injuries to overhead athletes of various ages. PMID:29845083

Towards the Detection of Explosive Taggants: Microwave and Millimetre-Wave Gas-Phase Spectroscopies of 3-Nitrotoluene.

PubMed

Roucou, Anthony; Kleiner, Isabelle; Goubet, Manuel; Bteich, Sabath; Mouret, Gael; Bocquet, Robin; Hindle, Francis; Meerts, W Leo; Cuisset, Arnaud

2018-05-07

The monitoring of gas-phase mononitrotoluenes is crucial for defence, civil security and environmental interests because they are used as taggant for TNT detection and in the manufacturing of industrial compounds such as dyestuffs. In this study, we have succeeded to measure and analyse at high-resolution a room temperature rotationally resolved millimetre-wave spectrum of meta-nitrotoluene (3-NT). Experimental and theoretical difficulties have been overcome, in particular, those related to the low vapour pressure of 3-NT and to the presence of a CH 3 internal rotation in an almost free rotation regime (V 3 =6.7659(24) cm -1 ). Rotational spectra have been recorded in the microwave and millimetre-wave ranges using a supersonic jet Fourier Transform microwave spectrometer (T rot <10 K) and a millimetre-wave frequency multiplication chain (T=293 K), respectively. Spectral analysis of pure rotation lines in the vibrational ground state and in the first torsional excited state supported by quantum chemistry calculations permits the rotational energy of the molecule, the hyperfine structure due to the 14 N nucleus, and the internal rotation of the methyl group to be characterised. A line list is provided for future in situ detection. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rotational and peak torque stiffness of rugby shoes.

PubMed

Ballal, Moez S; Usuelli, Federico Giuseppe; Montrasio, Umberto Alfieri; Molloy, Andy; La Barbera, Luigi; Villa, Tomaso; Banfi, Giuseppe

2014-09-01

Sports people always strive to avoid injury. Sports shoe designs in many sports have been shown to affect traction and injury rates. The aim of this study is to demonstrate the differing stiffness and torque in rugby boots that are designed for the same effect. Five different types of rugby shoes commonly worn by scrum forwards were laboratory tested for rotational stiffness and peak torque on a natural playing surface generating force patterns that would be consistent with a rugby scrum. The overall internal rotation peak torque was 57.75±6.26 Nm while that of external rotation was 56.55±4.36 Nm. The Peak internal and external rotational stiffness were 0.696±0.1 and 0.708±0.06 Nm/deg respectively. Our results, when compared to rotational stiffness and peak torques of football shoes published in the literature, show that shoes worn by rugby players exert higher rotational and peak torque stiffness compared to football shoes when tested on the same natural surfaces. There was significant difference between the tested rugby shoes brands. In our opinion, to maximize potential performance and lower the potential of non-contact injury, care should be taken in choosing boots with stiffness appropriate to the players main playing role. Copyright © 2014 Elsevier Ltd. All rights reserved.

Tracking single-particle rotation during macrophage uptake

DOE PAGES

Sanchez, Lucero; Patton, Paul; Anthony, Stephen Michael; ...

2015-06-10

We investigated the rotational dynamics of single microparticles during their internalization by macrophage cells. The microparticles used were triblock patchy particles that display two fluorescent patches on their two poles. The optical anisotropy made it possible to directly visualize and quantify the orientation and rotation of the particles. We show that particles exhibit a mixture of fast and slow rotation as they are uptaken by macrophages and transiently undergo directional rotation during their entry into the cell. As a result, the size of the particles and the surface presentation of ligands exerted a negligible influence on this heterogeneity of particlemore » rotation.« less

Hip and ankle range of motion and hip muscle strength in young female ballet dancersand controls

PubMed Central

Bennell, K.; Khan, K. M.; Matthews, B.; De Gruyter, M.; Cook, E.; Holzer, K.; Wark, J. D.

1999-01-01

OBJECTIVES: To compare the hip and ankle range of motion and hip muscle strength in 8-11 year old novice female ballet dancers and controls. METHODS: Subjects were 77 dancers and 49 controls (mean (SD) age 9.6 (0.8) and 9.6 (0.7) years respectively). Supine right active hip external rotation (ER) and internal rotation (IR) were measured using an inclinometer. A turnout protractor was used to assess standing active turnout range. The measure of ER achieved from below the hip during turnout (non-hip ER) was calculated by subtracting hip ER range from turnout range, and hip ER:IR was derived by dividing ER range by IR range. Range of right weight bearing ankle dorsiflexion was measured in a standing lunge using two methods: the distance from the foot to the wall (in centimetres) and the angle of the shank to the vertical via an inclinometer (in degrees). Right calf muscle range was measured in weight bearing using an inclinometer. A manual muscle tester was used to assess right isometric hip flexor, internal rotator, external rotator, abductor, and adductor strength. RESULTS: Dancers had less ER (p<0.05) and IR (p<0.01) range than controls but greater ER:IR (p<0.01). Although there was no difference in turnout between groups, the dancers had greater non-hip ER. Dancers had greater range of ankle dorsiflexion than controls, measured in both centimetres (p<0.01) and degrees (p<0.05), but similar calf muscle range. After controlling for body weight, controls had stronger hip muscles than dancers except for hip abductor strength which was similar. Regression analyses disclosed a moderate relation between turnout and hip ER (r = 0.40). There were no significant correlations between range of motion and training years and weekly training hours. CONCLUSIONS: Longitudinal follow up will assist in determining whether or not hip and ankle range in young dancers is genetically fixed and unable to be improved with further balletic training. 


 PMID:10522638

Modelling of the rotational moulding process for the manufacture of plastic products

NASA Astrophysics Data System (ADS)

Khoon, Lim Kok

The present research is mainly focused on two-dimensional non-linear thermal modelling, numerical procedures and software development for the rotational moulding process. The RotoFEM program is developed for the rotational moulding process using finite element procedures. The program is written in the MATLAB environment. The research includes the development of new slip flow models, phase change study, warpage study and process analyses. A new slip flow methodology is derived for the heat transfer problem inside the enclosed rotating mould during the heating stage of the tumbling powder. The methodology enables the discontinuous powder to be modelled by the continuous-based finite element method. The Galerkin Finite Element Method is incorporated with the lumped-parameter system and the coincident node technique in finding the multi-interacting heat transfer solutions inside the mould. Two slip flow models arise from the slip flow methodology; they are SDM (single-layered deposition method) and MDM (multi-layered deposition method). These two models have differences in their thermal description for the internal air energy balance and the computational procedure for the deposition of the molten polymer. The SDM model assumes the macroscopic deposition of the molten polymer bed exists only between the bed and the inner mould surface. On the other hand, the MDM model allows the layer-by-layer deposition of the molten polymer bed macroscopically. In addition, the latter has a more detailed heat transfer description for the internal air inside the mould during the powder heating cycle. In slip flow models, the semi-implicit approach has been introduced to solve the final quasi-equilibrium internal air temperature during the heating cycle. A notable feature of this slip flow methodology is that the slip flow models are capable of producing good results for the internal air at the heating powder stage, without the consideration of the powder movement and changeable powder mass. This makes the modelling of the rotational moulding process much simpler. In the simulation of the cooling stage in rotational moulding, the thermal aspects of the inherent warpage problem and external-internal cooling method have been explored. The predicted internal air temperature profiles have shown that the less apparent crystallization plateau in the experimental internal air in practice could be related to warpage. Various phase change algorithms have been reviewed and compared, and thus the most convenient and considerable effective algorithm is proposed. The dimensional analysis method, expressed by means of dimensionless combinations of physical, boundary, and time variables, is utilized to study the dependence of the key thermal parameters on the processing times of rotational moulding. Lastly, the predicted results have been compared with the experimental results from two different external resources. The predicted temperature profiles of the internal air, oven times and other process conditions are consistent with the available data.

The impact of rotator cuff tendinopathy on proprioception, measuring force sensation.

PubMed

Maenhout, Annelies G; Palmans, Tanneke; De Muynck, Martine; De Wilde, Lieven F; Cools, Ann M

2012-08-01

The impact of rotator cuff tendinopathy and related impingement on proprioception is not well understood. Numerous quantitative and qualitative changes in shoulder muscles have been shown in patients with rotator cuff tendinopathy. These findings suggest that control of force might be affected. This investigation wants to evaluate force sensation, a submodality of proprioception, in patients with rotator cuff tendinopathy. Thirty-six patients with rotator cuff tendinopathy and 30 matched healthy subjects performed force reproduction tests to isometric external and internal rotation to investigate how accurately they could reproduce a fixed target (50% MVC). Relative error, constant error, and force steadiness were calculated to evaluate respectively magnitude of error made during the test, direction of this error (overshoot or undershoot), and fluctuations of produced forces. Patients significantly overshoot the target (mean, 6.04% of target) while healthy subjects underestimate the target (mean, -5.76% of target). Relative error and force steadiness are similar in patients with rotator cuff tendinopathy and healthy subjects. Force reproduction tests, as executed in this study, were found to be highly reliable (ICC 0.849 and 0.909). Errors were significantly larger during external rotation tests, compared to internal rotation. Patients overestimate the target during force reproduction tests. This should be taken into account in the rehabilitation of patients with rotator cuff tendinopathy; however, precision of force sensation and steadiness of force exertion remains unaltered. This might indicate that control of muscle force is preserved. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Close binary evolution. II. Impact of tides, wind magnetic braking, and internal angular momentum transport

NASA Astrophysics Data System (ADS)

Song, H. F.; Meynet, G.; Maeder, A.; Ekström, S.; Eggenberger, P.; Georgy, C.; Qin, Y.; Fragos, T.; Soerensen, M.; Barblan, F.; Wade, G. A.

2018-01-01

Context. Massive stars with solar metallicity lose important amounts of rotational angular momentum through their winds. When a magnetic field is present at the surface of a star, efficient angular momentum losses can still be achieved even when the mass-loss rate is very modest, at lower metallicities, or for lower-initial-mass stars. In a close binary system, the effect of wind magnetic braking also interacts with the influence of tides, resulting in a complex evolution of rotation. Aims: We study the interactions between the process of wind magnetic braking and tides in close binary systems. Methods: We discuss the evolution of a 10 M⊙ star in a close binary system with a 7 M⊙ companion using the Geneva stellar evolution code. The initial orbital period is 1.2 days. The 10 M⊙ star has a surface magnetic field of 1 kG. Various initial rotations are considered. We use two different approaches for the internal angular momentum transport. In one of them, angular momentum is transported by shear and meridional currents. In the other, a strong internal magnetic field imposes nearly perfect solid-body rotation. The evolution of the primary is computed until the first mass-transfer episode occurs. The cases of different values for the magnetic fields and for various orbital periods and mass ratios are briefly discussed. Results: We show that, independently of the initial rotation rate of the primary and the efficiency of the internal angular momentum transport, the surface rotation of the primary will converge, in a time that is short with respect to the main-sequence lifetime, towards a slowly evolving velocity that is different from the synchronization velocity. This "equilibrium angular velocity" is always inferior to the angular orbital velocity. In a given close binary system at this equilibrium stage, the difference between the spin and the orbital angular velocities becomes larger when the mass losses and/or the surface magnetic field increase. The treatment of the internal angular momentum transport has a strong impact on the evolutionary tracks in the Hertzsprung-Russell Diagram as well as on the changes of the surface abundances resulting from rotational mixing. Our modelling suggests that the presence of an undetected close companion might explain rapidly rotating stars with strong surface magnetic fields, having ages well above the magnetic braking timescale. Our models predict that the rotation of most stars of this type increases as a function of time, except for a first initial phase in spin-down systems. The measure of their surface abundances, together, when possible, with their mass-luminosity ratio, provide interesting constraints on the transport efficiencies of angular momentum and chemical species. Conclusions: Close binaries, when studied at phases predating any mass transfer, are key objects to probe the physics of rotation and magnetic fields in stars.

Understand rotating isothermal collapses yet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tohline, J.E.

1985-01-01

A scalar virial equation is used to describe the dynamic properties of equilibrium gas clouds, taking into account the relative effects of surface pressure, rotation, self gravity and internal isothermal pressure. Details concerning the internal structure of the clouds are ignored in order to obtain a globalized analytical expression. The obtained solution to the equation is found to agree with the surface-pressure-dominated model of Stahler (1983), and the rotation-dominated model of Hayashi, Narita, and Miyama (1982). On the basis of the analytical expression of virial equilibrium in the clouds, some of the limiting properties of isothermal clouds are described, andmore » a realistic starting model for cloud collapse is proposed. 18 references.« less

[The Throwing Shoulder].

PubMed

Wieser, Karl; Gerber, Christian; Meyer, Dominik C

2016-02-03

Repetitive top-performance of overhead athletes induces a tremendous stress for the throwing shoulder. Throwers reach rotational speed of their arm of more than 7000°/s with joint compression and distraction forces of more than 1000 N. This performance is tributary to adaption of the shoulder muscles and the joint itself. These adaptions may, however lead to two specific problems of the throwing shoulder: 1. The posterosuperior internal impingement of the rotator cuff and labrum between glenoid and humeral head during late cooking phase; 2. A decreased internal rotation of the glenohumeral joint (GIRD) with compensatory problems of the scapula-stabilizing muscles. Precise analysis of kinematics and pathomechanics aims to improve understanding and treatment of those specific problems of the throwing shoulder.

Broadband Ftmw Spectroscopy of 2-METHYLIMIDAZOLE and Complexes with Water and Argon

NASA Astrophysics Data System (ADS)

Medcraft, Chris; Heitkämper, Juliane; Mullaney, John C.; Walker, Nick

2017-06-01

The rotational spectrum of 2-methylimidazole has been measured using laser ablation chirped-pulse Fourier transform microwave spectroscopy from 2-18.5 GHz. 2-methylimidazole was laser vaporised then entrained within an argon buffer gas undergoing supersonic expansion allowing for efficient rotational cooling. Carbon-13 and nitrogen-15 isotopologues were measured in natural abundance and substitution coordinates have been determined. The barrier to internal rotation of the methyl group was found to be 122.697(20) cm^{-1}. Nuclear quadropole coupling constants for the two nitrogen nuclei were determined via a rigid rotor fit of the A internal rotor state. Complexes with water and argon were also observed and fit in a similar way.

International Space Station Node 1 is moved for leak test

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first element for the International Space Station, and attached Pressurized Mating Adapter-1 continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node is being removed from the element rotation stand, or test stand, where it underwent an interim weight and center of gravity determination. (The final determination is planned to be performed prior to transporting Node 1 to the launch pad.) Now the node is being moved to the Shuttle payload transportation canister, where the doors will be closed for a two-week leak check. Node 1 is scheduled to fly on STS-88.

Clinical Assessment of Physical Examination Maneuvers for Rotator Cuff Lesions.

PubMed

Somerville, Lyndsay E; Willits, Kevin; Johnson, Andrew M; Litchfield, Robert; LeBel, Marie-Eve; Moro, Jaydeep; Bryant, Dianne

2014-08-01

Shoulder pain and disability pose a diagnostic challenge for clinicians owing to the numerous causes that exist. Unfortunately, the evidence in support of most clinical tests is weak or absent. To determine the diagnostic validity of physical examination maneuvers for rotator cuff lesions. Cohort study (diagnosis); Level of evidence, 1. Consecutive shoulder patients recruited for this study were referred to 2 tertiary orthopaedic clinics. A surgeon took a thorough history and indicated his or her certainty about each possible diagnosis. A clinician performed the physical examination for diagnoses where uncertainty remained. Arthroscopy was considered the reference standard for patients who underwent surgery, and MRI with arthrogram was considered the reference for patients who did not. The sensitivity, specificity, and likelihood ratios were calculated to investigate whether combinations of the top tests provided stronger predictions of the presence or absence of disease. There were 139 participants. None of the tests were highly sensitive for diagnosing rotator cuff tears or tendinosis. Tests for subscapularis tears were all highly specific. No optimal combination of tests improved the ability to correctly diagnose rotator cuff tears. Closer analysis revealed the internal rotation and lateral rotation lag sign did not improve the ability to diagnose subscapularis or supraspinatus tears, respectively, although the lateral rotation lag sign demonstrated a discriminatory ability for tear size. No test in isolation is sufficient to diagnose a patient with rotator cuff damage. A combination of tests improves the ability to diagnose damage to the rotator cuff. It is recommended that the internal rotation and lateral rotation lag signs be removed from the gamut of physical examination tests for supraspinatus and subscapularis tears. © 2014 The Author(s).

Method and system for measuring gate valve clearances and seating force

DOEpatents

Casada, Donald A.; Haynes, Howard D.; Moyers, John C.; Stewart, Brian K.

1996-01-01

Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner.

Gyrofluid Simulations of Intrinsic Rotation Generation in Reversed Shear Plasmas with Internal Transport Barriers

NASA Astrophysics Data System (ADS)

Jhang, Hogun; Kim, S. S.; Kwon, J. M.; Terzolo, L.; Kim, J. Y.; Diamond, P. H.

2010-11-01

It is accepted that the intrinsic rotation is generated via the residual stress, which is non-diffusive components of the turbulent Reynolds stress, without external momentum input. The physics leading to the onset of intrinsic rotation in L- and H- mode plasmas have been elucidated elsewhere. However, the physics responsible for the generation and transport of the intrinsic rotation and its relationship to the formation of internal transport barriers (ITBs) in reversed shear (RS) plasmas have not been explored in detail, which is the main subject in the present work. The revised version of the global gyrofluid code TRB is used for this study. It is found that the large intrinsic rotation (˜10-30% of the ion sound speed depending on ITB characteristics) is generated near the ITB region and propagates into the core. The intrinsic rotation increases linearly as the temperature gradient at ITB position increases, albeit not indefinitely. Key parameters related to the symmetry breaking, such as turbulent intensity and its gradient, the flux surface averaged parallel wavenumber are evaluated dynamically during the ITB formation. In particular, the role of reversed shear and the q-profile curvature is presented in relation to the symmetry breaking in RS plasmas.

Intrinsic Rotation and Momentum Transport in Reversed Shear Plasmas with Internal Transport Barriers

NASA Astrophysics Data System (ADS)

Jhang, Hogun; Kim, S. S.; Diamond, P. H.

2010-11-01

The intrinsic rotation in fusion plasmas is believed to be generated via the residual stress without external momentum input. The physical mechanism responsible for the generation and transport of intrinsic rotation in L- and H-mode tokamak plasmas has been studied extensively. However, it is noted that the physics of intrinsic rotation generation and its relationship to the formation of internal transport barriers (ITBs) in reversed shear (RS) tokamak plasmas have not been explored in detail, which is the main subject in the present work. A global gyrofluid code TRB is used for this study. It is found that the large intrinsic rotation (˜10-30% of the ion sound speed depending on ITB characteristics) is generated near the ITB region and propagates into the core. The intrinsic rotation increases linearly as the temperature gradient at ITB position increases, albeit not indefinitely. Key parameters related to the symmetry breaking, such as turbulent intensity and its gradient, the flux surface averaged parallel wavenumber are evaluated dynamically during the ITB formation. The role of reversed shear and the q-profile curvature is presented in relation to the symmetry breaking mechanism in RS plasmas.

Modeling human vestibular responses during eccentric rotation and off vertical axis rotation

NASA Technical Reports Server (NTRS)

Merfeld, D. M.; Paloski, W. H. (Principal Investigator)

1995-01-01

A mathematical model has been developed to help explain human multi-sensory interactions. The most important constituent of the model is the hypothesis that the nervous system incorporates knowledge of sensory dynamics into an "internal model" of these dynamics. This internal model allows the nervous system to integrate the sensory information from many different sensors into a coherent estimate of self-motion. The essence of the model is unchanged from a previously published model of monkey eye movement responses; only a few variables have been adjusted to yield the prediction of human responses. During eccentric rotation, the model predicts that the axis of eye rotation shifts slightly toward alignment with gravito-inertial force. The model also predicts that the time course of the perception of tilt following the acceleration phase of eccentric rotation is much slower than that during deceleration. During off vertical axis rotation (OVAR) the model predicts a small horizontal bias along with small horizontal, vertical, and torsional oscillations. Following OVAR stimulation, when stopped right- or left-side down, a small vertical component is predicted that decays with the horizontal post-rotatory response. All of the predictions are consistent with measurements of human responses.

Cervico-ocular coordination during neck rotation is distorted in people with whiplash-associated disorders.

PubMed

Bexander, Catharina S M; Hodges, Paul W

2012-03-01

People with whiplash-associated disorders (WAD) not only suffer from neck/head pain, but commonly report deficits in eye movement control. Recent work has highlighted a strong relationship between eye and neck muscle activation in pain-free subjects. It is possible that WAD may disrupt the intricate coordination between eye and neck movement. Electromyographic activity (EMG) of muscles that rotate the cervical spine to the right (left sternocleidomastoid, right obliquus capitis inferior (OI), right splenius capitis (SC) and right multifidus (MF)) was recorded in nine people with chronic WAD. Cervical rotation was performed with five gaze conditions involving different gaze directions relative to cervical rotation. The relationship between eye position/movement and neck muscle activity was contrasted with previous observations from pain-free controls. Three main differences were observed in WAD. First, the superficial muscle SC was active with both directions of cervical rotation in contrast to activity only with right rotation in pain-free controls. Second, activity of OI and MF varied between directions of cervical rotation, unlike the non-direction-specific activity in controls. Third, the effect of horizontal gaze direction on neck muscle EMG was augmented compared to controls. These observations provide evidence of redistribution of activity between neck muscles during cervical rotation and increased interaction between eye and neck muscle activity in people with WAD. These changes in cervico-ocular coordination may underlie clinical symptoms reported by people with WAD that involve visual deficits and changes in function during cervical rotation such as postural control.

Effect of the cosmological constant on the deflection angle by a rotating cosmic string

NASA Astrophysics Data System (ADS)

Jusufi, Kimet; Övgün, Ali

2018-03-01

We report the effect of the cosmological constant and the internal energy density of a cosmic string on the deflection angle of light in the spacetime of a rotating cosmic string with internal structure. We first revisit the deflection angle by a rotating cosmic string and then provide a generalization using the geodesic equations and the Gauss-Bonnet theorem. We show there is an agreement between the two methods when employing higher-order terms of the linear mass density of the cosmic string. By modifying the integration domain for the global conical topology, we resolve the inconsistency between these two methods previously reported in the literature. We show that the deflection angle is not affected by the rotation of the cosmic string; however, the cosmological constant Λ strongly affects the deflection angle, which generalizes the well-known result.

Identity physics experiment on internal transport barriers in JT-60U and JET

NASA Astrophysics Data System (ADS)

de Vries, P. C.; Sakamoto, Y.; Litaudon, X.; Beurskens, M. N. A.; Brix, M.; Crombé, K.; Fujita, T.; Giroud, C.; Hawkes, N. C.; Hayashi, N.; Joffrin, E.; Mantica, P.; Matsunaga, G.; Oyama, N.; Parail, V.; Salmi, A.; Shinohara, K.; Strintzi, D.; Suzuki, T.; Takechi, M.; Takenaga, H.; Tala, T.; Tsalas, M.; Urano, H.; Voitsekhovitch, I.; Yoshida, M.; EFDA contributors, JET; JT-60 Team

2009-12-01

A series of experiments have been carried out in 2008 at JT-60U and JET to find common characteristics and explain differences between internal transport barriers (ITBs). The identity experiments succeeded in matching the profiles of most dimensionless parameters at the time ITBs were triggered. Thereafter the q-profile development deviated due to differences in non-inductive current density profile, affecting the ITB. Furthermore, the ITBs in JET were more strongly influenced by the H-mode pedestal or edge localized modes. It was found to be difficult to match the plasma rotation characteristics in both devices. However, the wide range of Mach numbers obtained in these experiments shows that the rotation has little effect on the triggering of ITBs in plasmas with reversed magnetic shear. On the other hand the toroidal rotation and more specifically the rotational shear had an impact on the subsequent growth and allowed the formation of strong ITBs.

A Study on the Internal Structure of Heumgyeonggaknu

NASA Astrophysics Data System (ADS)

Kim, Sang Hyuk; Lee, Yong Sam; Lee, Min Soo; Ham, Sun Young

2013-06-01

Heumgyeonggaknu is a water-hammering type automatic water clock which was made by Jang Yeong-Sil in 1438. The water clock that is located in Heumgyeonggaknu consists of Suho which is equipped with 2-stage overflow. Constant water wheel power is generated by supplying a fixed amount of water of Suho to Sususang, and this power is transferred to each floor at the same time. The 1st floor rotation wheel of Gasan consists of the operation structure which has the shape of umbrella ribs. The 2nd floor rotation wheel is made so that the 12 hour signal, Gyeong-Jeom signal, and Jujeon constitute a systematic configuration. The 3rd floor rotation wheel is made so that the signal and rotation of Ongnyeo and four gods can be accomplished. Based on the above conceptual design, this paper analyzed the internal signal generation and power transmission of Heumgyeonggaknu.

A Relationship Between the Solar Rotation and Activity Analysed by Tracing Sunspot Groups

NASA Astrophysics Data System (ADS)

Ruždjak, Domagoj; Brajša, Roman; Sudar, Davor; Skokić, Ivica; Poljančić Beljan, Ivana

2017-12-01

The sunspot position published in the data bases of the Greenwich Photoheliographic Results (GPR), the US Air Force Solar Optical Observing Network and National Oceanic and Atmospheric Administration (USAF/NOAA), and of the Debrecen Photoheliographic Data (DPD) in the period 1874 to 2016 were used to calculate yearly values of the solar differential-rotation parameters A and B. These differential-rotation parameters were compared with the solar-activity level. We found that the Sun rotates more differentially at the minimum than at the maximum of activity during the epoch 1977 - 2016. An inverse correlation between equatorial rotation and solar activity was found using the recently revised sunspot number. The secular decrease of the equatorial rotation rate that accompanies the increase in activity stopped in the last part of the twentieth century. It was noted that when a significant peak in equatorial rotation velocity is observed during activity minimum, the next maximum is weaker than the previous one.

Geriatrics education is associated with positive attitudes toward older people in internal medicine residents: a multicenter study.

PubMed

Tufan, Fatih; Yuruyen, Mehmet; Kizilarslanoglu, Muhammet Cemal; Akpinar, Timur; Emiksiye, Sirhan; Yesil, Yusuf; Ozturk, Zeynel Abidin; Bozbulut, Utku Burak; Bolayir, Basak; Tasar, Pinar Tosun; Yavuzer, Hakan; Sahin, Sevnaz; Ulger, Zekeriya; Ozturk, Gulistan Bahat; Halil, Meltem; Akcicek, Fehmi; Doventas, Alper; Kepekci, Yalcin; Ince, Nurhan; Karan, Mehmet Akif

2015-01-01

The number of older people is growing fast in Turkey. In this context, internal medicine residents and specialists contact older people more frequently. Thus, healthcare providers' knowledge and attitudes toward older people is becoming more important. Studies that specifically investigate internal medicine residents' attitudes toward the elderly are scarce. We aimed to investigate the attitudes of internal medicine residents toward older people. This cross-sectional multicenter study was undertaken in the internal medicine clinics of six university state hospitals that provide education in geriatric care. All internal medicine residents working in these hospitals were invited to participate in this questionnaire study between March 2013 and December 2013. We recorded the participants' age, sex, duration of internal medicine residency, existence of relatives older than 65 years, history of geriatrics course in medical school, geriatrics rotation in internal medicine residency, and nursing home visits. A total of 274 (82.3%) of the residents participated in this study, and 83.6% of them had positive attitudes toward older people. A geriatrics rotation during internal medicine residency was the only independent factor associated with positive attitudes toward the elderly in this multivariate analysis. A geriatrics course during medical school was associated with positive attitudes in the univariate analysis, but only tended to be so in the multivariate analysis. Geriatrics rotation during internal medicine residency was independently associated with positive attitudes toward older people. Generalization of geriatrics education in developing countries may translate into a better understanding and improved care for older patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Assessment of tibial rotation and meniscal movement using kinematic magnetic resonance imaging

PubMed Central

2014-01-01

Objective This work aimed to assess tibial rotations, meniscal movements, and morphological changes during knee flexion and extension using kinematic magnetic resonance imaging (MRI). Methods Thirty volunteers with healthy knees were examined using kinematic MRI. The knees were imaged in the transverse plane with flexion and extension angles from 0° to 40° and 40° to 0°, respectively. The tibial interior and exterior rotation angles were measured, and the meniscal movement range, height change, and side movements were detected. Results The tibia rotated internally (11.55° ± 3.20°) during knee flexion and rotated externally (11.40° ± 3.0°) during knee extension. No significant differences were observed between the internal and external tibial rotation angles (P > 0.05), between males and females (P > 0.05), or between the left and right knee joints (P > 0.05). The tibial rotation angle with a flexion angle of 0° to 24° differed significantly from that with a flexion angle of 24° to 40° (P < 0.01). With knee flexion, the medial and lateral menisci moved backward and the height of the meniscus increased. The movement range was greater in the anterior horn than in the posterior horn and greater in the lateral meniscus than in the medial meniscus (P < 0.01). During backward movements of the menisci, the distance between the anterior and posterior horns decreased, with the decrease more apparent in the lateral meniscus (P < 0.01). The side movements of the medial and lateral menisci were not obvious, and a smaller movement range was found than that of the forward and backward movements. Conclusion Knee flexion and extension facilitated internal and external tibial rotations, which may be related to the ligament and joint capsule structure and femoral condyle geometry. PMID:25142267

The Hospitalist Huddle: a 1-year experience of teaching Hospital Medicine utilizing the concept of peer teaching in medical education.

PubMed

Elhassan, Mohammed

2017-01-01

The relatively new specialty of Hospital Medicine in the USA is one of the fastest growing fields in internal medicine. Academic hospitalists are largely involved in the medical education of postgraduate residents and medical students. Little is known about the effectiveness of peer-to-peer teaching in internal medicine residency training programs and how the medical residents perceive its educational value in learning Hospital Medicine. The Hospitalist Huddle is a weekly educational activity newly established by our Hospitalist Division to facilitate the concept of peer-to-peer teaching. It requires medical residents to teach and educate their peers about the clinical topics related to Hospital Medicine. Faculty hospitalists serve as facilitators during the teaching sessions. A survey disseminated at the end of the first year of its implementation examined the residents' perception of the educational value of this new teaching activity. Most residents reported that they see the Huddle as a useful educational forum which may improve their skills in teaching, create a better educational and learning environment during their inpatient rotation, and improve their understanding of Hospital Medicine. Most residents also prefer that their peers, rather than faculty hospitalists, run the activity and do the teaching. The survey results support the notion that teaching and learning with flat hierarchies can be an appealing educational method to medical residents to help them understand Hospital Medicine during their medical wards rotation. Some areas need to be improved and others need to be continued and emphasized in order to make this novel educational activity grow and flourish in terms of its educational value and residents' satisfaction.

Learning, education and satisfaction after compulsory rotating internship in Kathmandu University Medical School: a qualitative study of interns' response.

PubMed

Shrestha, D; Mishra, B

2008-01-01

Internship is an integral part of MBBS training programme and mandatory to all students. Kathmandu University Medical School has adopted a programme of compulsory one year rotating internship including 6 weeks community exposure in out reach clinics for the first batch of students. The purpose of the study is to evaluate interns' feedback concerning learning, education and satisfaction. A questionnaire with 47 items was administered to 30 interns who had finished one year rotating internship in Kathmandu University Medical School. Fourty-two responses were graded according in Likert scale and 5 open ended questions were analyzed for common themes. The mean age of the interns was 24.77+/-0.67 yrs with female: male ratio of 1.5:1. Confidence level of communication of interns with faculties was lesser than with junior doctors and patients. Junior doctors and colleagues contributed more in interns' learning than faculties. Community exposure for 6 weeks was considered lengthy and lacking of clear objectives. However, 53.3% interns agreed that achievement of objectives of community posting was high or very high. Of the interns, 50% perceived certain degree of physical or mental or sexual harassment during internship. Interns raised the issue of not involving them as a part of team during clinical posting. Clinical competencies for most of the skills were high or very high. Interns have learned clinical skills and patient care in one year internship programme but contribution of junior doctors and colleague are more than teachers. Clear objectives are needed before clinical and community postings. Process of providing regular feedback from interns and vice versa should be implemented to improve interns' learning, education and satisfaction.

IERS Conventions (2003)

DTIC Science & Technology

2004-01-01

International Earth Rotation and Reference Systems Service (IERS) Service International de la Rotation Terrestre et des Systèmes de Référence IERS...Equation for the determination of the density of moist air (1981/91),” Metrologia , 29, pp. 67–70. Giacomo, P., 1982, “Equation for the determination of...the density of moist air (1981),” Metrologia , 18, pp. 33–40. Herring, T. A., 1992, “Modeling Atmospheric Delays in the Analysis of Space Geodetic Data

[Manipulative reduction and percutaneous Kirschner wire internal fixation for grade IV supination-external rotation ankle fractures].

PubMed

Li, Jia; Sun, Jin-Ke; Wang, Chen-Lin

2017-06-25

To investigate surgical skills and clinical effects of manipulative reduction and percutaneous Kirschner wire internal fixation in treating grade IV supination-external rotation ankle fractures. From May 2013 to October 2016, 35 patients with grade IV supination-external rotation ankle fractures were treated with percutaneous Kirschner wire internal fixation, involving 22 males and 13 females with an average age of 38.2 years ranged from 18 to 65 years old. The time from injury to operation ranged from 2 h to 10 d with an average of 5 d. Reduction quality was assessed by Burwell-Charnley radiological criteria. Baird-Jackson ankle scoring system was used to assess clinical effects. Thirty-three patients were followed up from 10 to 28 months with an average of 14 months. Fracture healing time ranged from 10 to 18 weeks with an average of 12 weeks. According to Burwell-Charnley radiological criteria, 30 cases were obtained anatomic reduction, 3 cases moderate. According to Baird-Jackson ankle scoring system, total score was 93.8±5.4, 17 cases got excellent result, 12 good, 2 fair and 2 poor. Manipulative reduction and percutaneous Kirschner wire internal fixation in treating grade IV supination-external rotation ankle fractures has advantages of reliable efficacy, less complications. But higher require techniques were required for closed reduction. It is not suitable for severe crushed fracture and compressive articular surface fracture.

Avoiding Pitfalls of Tibiotalocalcaneal Nail Malposition With Internal Rotation Axial Heel View.

PubMed

Callahan, Ryan; Juliano, Paul; Aydogan, Umur; Clayton, Justin

2018-04-01

Tibiotalocalcaneal (TTC) nails are often used for complex hind foot arthrodesis and deformity correction. The natural valgus alignment of the hindfoot creates a challenge to optimum placement of the guidewire and eventual nail with a straight or valgus-curved nail. Five fresh frozen cadavers were used for placement of a TTC guidewire with standard anterior-posterior (AP), lateral, and Harris axial heel views as a reference for proper placement. The limb was then rotated 15°, 30°, and 45° both internally and externally to evaluate the perceived amount of osseous purchase within the calcaneus. The TTC nail was then inserted and dissection was performed to demonstrate proximity of the nail to the sustentaculum tali and neurovascular structures. A 30° internal rotation Harris axial heel view demonstrated the most accurate representation of osseous purchase within the calcaneus with the guidewire and nail placement. When the guidewire was placed with standard imaging the nail was often ultimately placed in close proximity to the sustentaculum tali and neurovascular structures. Careful placement of the guidewire prior to reaming and nail placement should be undertaken to avoid neurovascular injury and to increase osseous purchase. For optimal guidewire placement, the authors suggest using appropriate anatomic landmarks and using a 30° internally rotated Harris axial heel view to verify correct placement. Level V: Expert opinion.

Nonlinear calculation of the m=1 internal kink instability in current carrying stellarators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wakatani, M.

1978-02-01

Nonlinear properties of the m=1 internal kink mode are shown in a low beta current carrying stellarator. The effects of the external helical magnetic fields are considered through a rotational transform and the magnetic surface is assumed to be circular. Magnetic surfaces inside the iota sub eta + iota sub sigma = 1 surface shift and deform non-circularly, while magnetic surfaces outside the iota sub eta + iota sub sigma = 1 are not disturbed, where iota sub eta is a rotational transform due to helical magnetic fields and iota sub sigma is due to a plasma current. Many highermore » harmonics are excited after the fundamental mode saturates. When the external helical magnetic fields are lowered, the m=1 tearing mode similar to that in a low beta Tokamak grows and magnetic islands appear near the iota sub eta + iota sub sigma = 1 surface. For adequate helical magnetic fields, the current carrying stellarator becomes stable against both the m=1 internal kink mode and the m=1 internal kink mode and the m=1 tearing mode, without lowering the rotational transform.« less

Improved rotation-activity-age relations in Sun-like stars

NASA Astrophysics Data System (ADS)

Meléndez, Jorge; dos Santos, Leonardo A.; Freitas, Fabrício C.

2017-10-01

The evolution of rotational velocity and magnetic activity with age follows approximately a t -1/2 relation, the famous Skumanich law. Using a large sample of about 80 solar twins with precise ages, we show departures from this law. We found a steep drop in rotational velocity and activity in the first 2-3 Gyr and afterwards there seems to be a shallow decrease. Our inferred rotational periods suggest that the Sun will continue to slow down, validating thus the use of gyrochronology beyond solar age. The Sun displays normal rotational velocity and activity when compared to solar twins of solar age. We also show that stars with exceedingly high stellar activity for their age are spectroscopic binaries that also exhibit enhanced rotational velocities and chemical signatures of mass transfer.

Hip rotation angle is associated with frontal plane knee joint mechanics during running.

PubMed

Sakaguchi, Masanori; Shimizu, Norifumi; Yanai, Toshimasa; Stefanyshyn, Darren J; Kawakami, Yasuo

2015-02-01

Inability to control lower extremity segments in the frontal and transverse planes resulting in large knee abduction angle and increased internal knee abduction impulse has been associated with patellofemoral pain (PFP). However, the influence of hip rotation angles on frontal plane knee joint kinematics and kinetics remains unclear. The purpose of this study was to explore how hip rotation angles are related to frontal plane knee joint kinematics and kinetics during running. Seventy runners participated in this study. Three-dimensional marker positions and ground reaction forces were recorded with an 8-camera motion analysis system and a force plate while subjects ran along a 25-m runway at a speed of 4m/s. Knee abduction, hip rotation and toe-out angles, frontal plane lever arm at the knee, internal knee abduction moment and impulse, ground reaction forces and the medio-lateral distance from the ankle joint center to the center of pressure (AJC-CoP) were quantified. The findings of this study indicate that greater hip external rotation angles were associated with greater toe-out angles, longer AJC-CoP distances, smaller internal knee abduction impulses with shorter frontal plane lever arms and greater knee abduction angles. Thus, there appears to exist a conflict between kinematic and kinetic risk factors of PFP, and hip external rotation angle may be a key factor to control frontal plane knee joint kinematics and kinetics. These results may help provide an appropriate manipulation and/or intervention on running style to reduce the risk of PFP. Copyright © 2014 Elsevier B.V. All rights reserved.

Heat Transfer Experiments in the Internal Cooling Passages of a Cooled Radial Turbine Rotor

NASA Technical Reports Server (NTRS)

Johnson, B. V.; Wagner, J. H.

1996-01-01

An experimental study was conducted (1) to experimentally measure, assess and analyze the heat transfer within the internal cooling configuration of a radial turbine rotor blade and (2) to obtain heat transfer data to evaluate and improve computational fluid dynamics (CFD) procedures and turbulent transport models of internal coolant flows. A 1.15 times scale model of the coolant passages within the NASA LERC High Temperature Radial Turbine was designed, fabricated of Lucite and instrumented for transient beat transfer tests using thin film surface thermocouples and liquid crystals to indicate temperatures. Transient heat transfer tests were conducted for Reynolds numbers of one-fourth, one-half, and equal to the operating Reynolds number for the NASA Turbine. Tests were conducted for stationary and rotating conditions with rotation numbers in the range occurring in the NASA Turbine. Results from the experiments showed the heat transfer characteristics within the coolant passage were affected by rotation. In general, the heat transfer increased and decreased on the sides of the straight radial passages with rotation as previously reported from NASA-HOST-sponsored experiments. The heat transfer in the tri-passage axial flow region adjacent to the blade exit was relatively unaffected by rotation. However, the heat transfer on one surface, in the transitional region between the radial inflow passage and axial, constant radius passages, decreased to approximately 20 percent of the values without rotation. Comparisons with previous 3-D numerical studies indicated regions where the heat transfer characteristics agreed and disagreed with the present experiment.

Prevalence of stress in junior doctors during their internship training: a cross-sectional study of three Saudi medical colleges’ hospitals

PubMed Central

Abdulghani, Hamza Mohammad; Irshad, Mohammad; Al Zunitan, Mohammed A; Al Sulihem, Ali A; Al Dehaim, Muhammed A; Al Esefir, Waleed A; Al Rabiah, Abdulaziz M; Kameshki, Rashid N; Alrowais, Nourah Abdullah; Sebiany, Abdulaziz; Haque, Shafiul

2014-01-01

Background Medical science is perceived as a stressful educational career, and medical students experience monstrous stress during their undergraduate studies, internship, and residency training, which affects their cognitive function, practical life, and patient care. In the present study, an assessment of the prevalence of self-perceived stress among new medical graduates during their internship training has been performed, and correlations of self-perceived stress with sex, marital status, and clinical rotations have been evaluated. Patients and methods Interns of the King Khalid, King Abdulaziz, and King Fahd University hospitals in Saudi Arabia were invited to complete a stress inventory known as the Kessler 10, which is used for stress measurement. Apart from stress evaluation, the questionnaire collected personal data, such as age, sex, and marital status, in addition to information relevant to hospital training, assigned duties, and clinical training rotations. Results Our results showed that nearly 73.0% of interns were under stressed conditions. Most of the interns were affected by a severe level of stress (34.9%), followed by mild (19.3%) and moderate (18.8%) levels of stress. The stress level was significantly higher (84.0%) among female interns in comparison with male interns (66.5%) (odds ratio =2.64; confidence interval =1.59–4.39; P<0.0002). There were statistically significant differences between the percentages of male and female interns (P≤0.047) at mild, moderate, and severe stress levels. Marital status had no role in causing stress. The highest stress level was reported by interns during the clinical rotations of medicine (78.8%), followed by surgery (74.7%), pediatrics (72.4%), obstetrics and gynecology (70.1%), and emergency (58.3%). The prevalence of stress among the interns and their corresponding clinical rotations in all three hospitals had significant linear correlations (r≥0.829, P≤0.041). Conclusion We found a significantly high level of stress among the medical interns. High stress may have negative effects on cognitive functioning, learning, and patient care. Hence, medical interns need support and subsequent interventions to cope with stress. PMID:25328389

Mechanical stability of the subtalar joint after lateral ligament sectioning and ankle brace application: a biomechanical experimental study.

PubMed

Kamiya, Tomoaki; Kura, Hideji; Suzuki, Daisuke; Uchiyama, Eiichi; Fujimiya, Mineko; Yamashita, Toshihiko

2009-12-01

The roles of each ligament supporting the subtalar joint have not been clarified despite several biomechanical studies. The effects of ankle braces on subtalar instability have not been shown. The ankle brace has a partial effect on restricting excessive motion of the subtalar joint. Controlled laboratory study. Ten normal fresh-frozen cadaveric specimens were used. The angular motions of the talus were measured via a magnetic tracking system. The specimens were tested while inversion and eversion forces, as well as internal and external rotation torques, were applied. The calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament were sectioned sequentially, and the roles of each ligament, as well as the stabilizing effects of the ankle brace, were examined. Complete sectioning of the ligaments increased the angle between the talus and calcaneus in the frontal plane to 51.7 degrees + or - 11.8 degrees compared with 35.7 degrees + or - 6.0 degrees in the intact state when inversion force was applied. There was a statistically significant difference in the angles between complete sectioning of the ligaments and after application of the brace (34.1 degrees + or - 7.3 degrees ) when inversion force was applied. On the other hand, significant differences in subtalar rotation were not found between complete sectioning of the ligaments and application of the brace when internal and external rotational torques were applied. The ankle brace limited inversion of the subtalar joint, but it did not restrict motion after application of internal or external rotational torques. In cases of severe ankle sprains involving the calcaneofibular ligament, cervical ligament, and interosseous talocalcaneal ligament injuries, application of an ankle brace might be less effective in limiting internal-external rotational instabilities than in cases of inversion instabilities in the subtalar joint. An improvement in the design of the brace is needed to restore better rotational stability in the subtalar joint.

A multicenter study: how do medical students perceive clinical learning climate?

PubMed Central

Yilmaz, Nilufer Demiral; Velipasaoglu, Serpil; Ozan, Sema; Basusta, Bilge Uzun; Midik, Ozlem; Mamakli, Sumer; Karaoglu, Nazan; Tengiz, Funda; Durak, Halil İbrahim; Sahin, Hatice

2016-01-01

Background The relationship between students and instructors is of crucial importance for the development of a positive learning climate. Learning climate is a multifaceted concept, and its measurement is a complicated process. The aim of this cross-sectional study was to determine medical students’ perceptions about the clinical learning climate and to investigate differences in their perceptions in terms of various variables. Methods Medical students studying at six medical schools in Turkey were recruited for the study. All students who completed clinical rotations, which lasted for 3 or more weeks, were included in the study (n=3,097). Data were collected using the Clinical Learning Climate Scale (CLCS). The CLCS (36 items) includes three subscales: clinical environment, emotion, and motivation. Each item is scored using a 5-point Likert scale (1: strongly disagree to 5: strongly agree). Results The response rate for the trainees was 69.67% (n=1,519), and for the interns it was 51.47% (n=917). The mean total CLCS score was 117.20±17.19. The rotation during which the clinical learning climate was perceived most favorably was the Physical Therapy and Rehabilitation rotation (mean score: 137.77). The most negatively perceived rotation was the General Internal Medicine rotation (mean score: 104.31). There were significant differences between mean total scores in terms of trainee/intern characteristics, internal medicine/surgical medicine rotations, and perception of success. Conclusion The results of this study drew attention to certain aspects of the clinical learning climate in medical schools. Clinical teacher/instructor/supervisor, clinical training programs, students’ interactions in clinical settings, self-realization, mood, students’ intrinsic motivation, and institutional commitment are important components of the clinical learning climate. For this reason, the aforementioned components should be taken into consideration in studies aiming to improve clinical learning climate. PMID:27640648

Lumbar lordosis angle and trunk and lower-limb electromyographic activity comparison in hip neutral position and external rotation during back squats

PubMed Central

Oshikawa, Tomoki; Morimoto, Yasuhiro; Kaneoka, Koji

2018-01-01

[Purpose] To compare the lumbar lordosis angle and electromyographic activities of the trunk and lower-limb muscles in the hip neutral position and external rotation during back squats. [Subjects and Methods] Ten healthy males without severe low back pain or lower-limb injury participated in this study. The lumbar lordosis angle and electromyographic activities were measured using three-dimensional motion-capture systems and surface electrodes during four back squats: parallel back squats in the hip neutral position and external rotation and full back squats in the hip neutral position and external rotation. A paired t-test was used to compare parallel and full back squats measurements in the hip neutral position and external rotation, respectively. [Results] During parallel back squats, the average lumbar lordosis angle was significantly larger in hip external rotation than in the hip neutral position. During full back squats, lumbar erector spinae and multifidus activities were significantly lower in hip external rotation than in the hip neutral position, whereas gluteus maximus activity was significantly higher in hip external rotation than in the hip neutral position. [Conclusion] The back squat in hip external rotation induced improvement of lumbar kyphosis, an increasing of the gluteus maximus activity and a decrease of both lumbar erector spinae and multifidus activities. PMID:29581666

Dynamo action and magnetic activity during the pre-main sequence: Influence of rotation and structural changes

NASA Astrophysics Data System (ADS)

Emeriau-Viard, Constance; Brun, Allan Sacha

2017-10-01

During the PMS, structure and rotation rate of stars evolve significantly. We wish to assess the consequences of these drastic changes on stellar dynamo, internal magnetic field topology and activity level by mean of HPC simulations with the ASH code. To answer this question, we develop 3D MHD simulations that represent specific stages of stellar evolution along the PMS. We choose five different models characterized by the radius of their radiative zone following an evolutionary track, from 1 Myr to 50 Myr, computed by a 1D stellar evolution code. We introduce a seed magnetic field in the youngest model and then we spread it through all simulations. First of all, we study the consequences that the increase of rotation rate and the change of geometry of the convective zone have on the dynamo field that exists in the convective envelop. The magnetic energy increases, the topology of the magnetic field becomes more complex and the axisymmetric magnetic field becomes less predominant as the star ages. The computation of the fully convective MHD model shows that a strong dynamo develops with a ratio of magnetic to kinetic energy reaching equipartition and even super-equipartition states in the faster rotating cases. Magnetic fields resulting from our MHD simulations possess a mixed poloidal-toroidal topology with no obvious dominant component. We also study the relaxation of the vestige dynamo magnetic field within the radiative core and found that it satisfies stability criteria. Hence it does not experience a global reconfiguration and instead slowly relaxes by retaining its mixed poloidal-toroidal topology.

Active tectonics of northwestern U.S. inferred from GPS-derived surface velocities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert McCaffrey; Robert W. King; Suzette J. Payne

2013-02-01

Surface velocities derived from GPS observations from 1993 to 2011 at several hundred sites across the deforming northwestern United States are used to further elucidate the region's active tectonics. The new velocities reveal that the clockwise rotations, relative to North America, seen in Oregon and western Washington from earlier GPS observations, continue to the east to include the Snake River Plain of Idaho and south into the Basin and Range of northern Nevada. Regional-scale rotation is attributed to gravitationally driven extension in the Basin and Range and Pacific-North America shear transferred through the Walker Lane belt aided by potentially strongmore » pinning below the Idaho Batholith. The large rotating section comprising eastern Oregon displays very low internal deformation rates despite seismological evidence for a thin crust, warm mantle, organized mantle flow, and elevated topography. The observed disparity between mantle and surface kinematics suggests that either little stress acts between them (low basal shear) or that the crust is strong relative to the mantle. The rotation of the Oregon block impinges on Washington across the Yakima fold-thrust belt where shortening occurs in a closing-fan style. Elastic fault locking at the Cascadia subduction zone is reevaluated using the GPS velocities and recently published uplift rates. The 18 year GPS and 80 year leveling data can both be matched with a common locking model suggesting that the locking has been stable over many decades. The rate of strain accumulation is consistent with hundreds of years between great subduction events.« less

Variable Star Discoveries for Research Education at the Phillips Academy Observatory

NASA Astrophysics Data System (ADS)

Odden, Caroline; Yoon, Seokjun; Zhu, Emily; Little, John; Taylor, Isabel; Kim, Ji Seok; Briggs, John W.

2014-06-01

The discovery and publication of unknown variable stars by high school students is a highly engaging activity in a new hands-on research course developed at Phillips Academy in Andover, Massachusetts. Students use MPO Canopus software to recognize candidate variable stars in image series typically recorded for asteroid rotation studies. Follow-up observations are made using the 16-inch DFM telescopes at the Phillips Academy Observatory and at the HUT Observatory near Eagle, Colorado, as well as with a remote-access 20-inch at New Mexico Skies Observatory near Mayhill, New Mexico. The Catalina Sky Survey can provide additional photometric measurements. Confirmed variables, with light curves and periods, are submitted to the International Variable Star Index and Journal of the American Association of Variable Star Observers. Asteroid rotation studies are published in Minor Planet Bulletin.

Physiologic adaptation of man in space; Proceedings of the Seventh International Man in Space Symposium, Houston, TX, Feb. 10-13, 1986

NASA Technical Reports Server (NTRS)

Holland, Albert W. (Editor)

1987-01-01

Topics discussed in this volume include space motion sickness, cardiovascular adaptation, fluid shifts, extravehicular activity, general physiology, perception, vestibular response modifications, vestibular physiology, and pharmacology. Papers are presented on the clinical characterization and etiology of space motion sickness, ultrasound techniques in space medicine, fluid shifts in weightlessness, Space Shuttle inflight and postflight fluid shifts measured by leg volume changes, and the probability of oxygen toxicity in an 8-psi space suit. Consideration is also given to the metabolic and hormonal status of crewmembers in short-term space flights, adaptive changes in perception of body orientation and mental image rotation in microgravity, the effects of a visual-vestibular stimulus on the vestibulo-ocular reflex, rotation tests in the weightless phase of parabolic flight, and the mechanisms of antimotion sickness drugs.

QUAGMIRE v1.3: a quasi-geostrophic model for investigating rotating fluids experiments

NASA Astrophysics Data System (ADS)

Williams, P. D.; Haine, T. W. N.; Read, P. L.; Lewis, S. R.; Yamazaki, Y. H.

2009-04-01

The QUAGMIRE model has recently been made freely available for public use. QUAGMIRE is a quasi-geostrophic numerical model for performing fast, high-resolution simulations of multi-layer rotating annulus laboratory experiments on a desktop personal computer. This presentation describes the model's main features. QUAGMIRE uses a hybrid finite-difference/spectral approach to numerically integrate the coupled nonlinear partial differential equations of motion in cylindrical geometry in each layer. Version 1.3 implements the special case of two fluid layers of equal resting depths. The flow is forced either by a differentially rotating lid, or by relaxation to specified streamfunction or potential vorticity fields, or both. Dissipation is achieved through Ekman layer pumping and suction at the horizontal boundaries, including the internal interface. The effects of weak interfacial tension are included, as well as the linear topographic beta-effect and the quadratic centripetal beta-effect. Stochastic forcing may optionally be activated, to represent approximately the effects of random unresolved features. A leapfrog time stepping scheme is used, with a Robert filter. Flows simulated by the model agree well with those observed in the corresponding laboratory experiments.

Enhanced Stellar Activity for Slow Antisolar Differential Rotation?

NASA Astrophysics Data System (ADS)

Brandenburg, Axel; Giampapa, Mark S.

2018-03-01

High-precision photometry of solar-like members of the open cluster M67 with Kepler/K2 data has recently revealed enhanced activity for stars with a large Rossby number, which is the ratio of rotation period to the convective turnover time. Contrary to the well established behavior for shorter rotation periods and smaller Rossby numbers, the chromospheric activity of the more slowly rotating stars of M67 was found to increase with increasing Rossby number. Such behavior has never been reported before, although it was theoretically predicted to emerge as a consequence of antisolar differential rotation (DR) for stars with Rossby numbers larger than that of the Sun, because in those models the absolute value of the DR was found to exceed that for solar-like DR. Using gyrochronological relations and an approximate age of 4 Gyr for the members of M67, we compare with computed rotation rates using just the B ‑ V color. The resulting rotation–activity relation is found to be compatible with that obtained by employing the measured rotation rate. This provides additional support for the unconventional enhancement of activity at comparatively low rotation rates and the possible presence of antisolar differential rotation.

3D finite element models of shoulder muscles for computing lines of actions and moment arms.

PubMed

Webb, Joshua D; Blemker, Silvia S; Delp, Scott L

2014-01-01

Accurate representation of musculoskeletal geometry is needed to characterise the function of shoulder muscles. Previous models of shoulder muscles have represented muscle geometry as a collection of line segments, making it difficult to account for the large attachment areas, muscle-muscle interactions and complex muscle fibre trajectories typical of shoulder muscles. To better represent shoulder muscle geometry, we developed 3D finite element models of the deltoid and rotator cuff muscles and used the models to examine muscle function. Muscle fibre paths within the muscles were approximated, and moment arms were calculated for two motions: thoracohumeral abduction and internal/external rotation. We found that muscle fibre moment arms varied substantially across each muscle. For example, supraspinatus is considered a weak external rotator, but the 3D model of supraspinatus showed that the anterior fibres provide substantial internal rotation while the posterior fibres act as external rotators. Including the effects of large attachment regions and 3D mechanical interactions of muscle fibres constrains muscle motion, generates more realistic muscle paths and allows deeper analysis of shoulder muscle function.

3D Finite Element Models of Shoulder Muscles for Computing Lines of Actions and Moment Arms

PubMed Central

Webb, Joshua D.; Blemker, Silvia S.; Delp, Scott L.

2014-01-01

Accurate representation of musculoskeletal geometry is needed to characterize the function of shoulder muscles. Previous models of shoulder muscles have represented muscle geometry as a collection of line segments, making it difficult to account the large attachment areas, muscle-muscle interactions, and complex muscle fiber trajectories typical of shoulder muscles. To better represent shoulder muscle geometry we developed three-dimensional finite element models of the deltoid and rotator cuff muscles and used the models to examine muscle function. Muscle fiber paths within the muscles were approximated, and moment arms were calculated for two motions: thoracohumeral abduction and internal/external rotation. We found that muscle fiber moment arms varied substantially across each muscle. For example, supraspinatus is considered a weak external rotator, but the three-dimensional model of supraspinatus showed that the anterior fibers provide substantial internal rotation while the posterior fibers act as external rotators. Including the effects of large attachment regions and three-dimensional mechanical interactions of muscle fibers constrains muscle motion, generates more realistic muscle paths, and allows deeper analysis of shoulder muscle function. PMID:22994141

The effect of platelet-rich plasma on arthroscopic double-row rotator cuff repair: a clinical study with 12-month follow-up.

PubMed

Zhang, Zhenxiang; Wang, Yong; Sun, Junying

2016-01-01

The aim of the study was to assess the effect of platelet-rich plasma on arthroscopic double-row rotator cuff repair. The study included 60 patients with arthroscopic rotator cuff repair. Thirthy patients (mean age: 57.2±7.4; 16 males and 14 females) underwent arthroscopic double-row repair alone (Group 1), another 30 (mean age: 56.9±6.0; 15 males and 15 females) had an injection of platelet-rich plasma (PRP) (Group 2). The groups were compared with DASH as a primary outcome score and Constant-Murley score, visual analog scale, measurement of active forward flexion, and external and internal rotation as secondary outcome measures. Magnetic resonance imaging was used to assess the integrity of the repair at 12 months postoperatively. Primary and secondary outcome measures statistically improved in both groups postoperatively (p<0.05). Overall mean primary and secondary postoperative outcome measures were not significantly different between the 2 groups. A retear was seen in 9 subjects (30%) in Group 1 and 4 subjects (14%) in Group 2 (p<0.05). The local injection of PRP into a primary arthroscopic double-row cuff repair resulted in lower recurrence rates than repairs without the novel biological augmentation material.

Rational design and dynamics of self-propelled colloidal bead chains: from rotators to flagella.

PubMed

Vutukuri, Hanumantha Rao; Bet, Bram; van Roij, René; Dijkstra, Marjolein; Huck, Wilhelm T S

2017-12-01

The quest for designing new self-propelled colloids is fuelled by the demand for simple experimental models to study the collective behaviour of their more complex natural counterparts. Most synthetic self-propelled particles move by converting the input energy into translational motion. In this work we address the question if simple self-propelled spheres can assemble into more complex structures that exhibit rotational motion, possibly coupled with translational motion as in flagella. We exploit a combination of induced dipolar interactions and a bonding step to create permanent linear bead chains, composed of self-propelled Janus spheres, with a well-controlled internal structure. Next, we study how flexibility between individual swimmers in a chain can affect its swimming behaviour. Permanent rigid chains showed only active rotational or spinning motion, whereas longer semi-flexible chains showed both translational and rotational motion resembling flagella like-motion, in the presence of the fuel. Moreover, we are able to reproduce our experimental results using numerical calculations with a minimal model, which includes full hydrodynamic interactions with the fluid. Our method is general and opens a new way to design novel self-propelled colloids with complex swimming behaviours, using different complex starting building blocks in combination with the flexibility between them.

KSC01padig007

NASA Image and Video Library

2001-01-03

KENNEDY SPACE CENTER, Fla. -- Under wispy white morning clouds, Space Shuttle Atlantis nears the Rotating Service Structure on Launch Pad 39A. Atlantis will fly on mission STS-98, the seventh construction flight to the International Space Station, carrying the U.S. Laboratory, named Destiny. The lab will have five system racks already installed inside the module. After delivery of electronics in the lab, electrically powered attitude control for Control Moment Gyroscopes will be activated. Atlantis is scheduled for launch no earlier than Jan. 19, 2001, with a crew of five

Turbo-generator control with variable valve actuation

DOEpatents

Vuk, Carl T [Denver, IA

2011-02-22

An internal combustion engine incorporating a turbo-generator and one or more variably activated exhaust valves. The exhaust valves are adapted to variably release exhaust gases from a combustion cylinder during a combustion cycle to an exhaust system. The turbo-generator is adapted to receive exhaust gases from the exhaust system and rotationally harness energy therefrom to produce electrical power. A controller is adapted to command the exhaust valve to variably open in response to a desired output for the turbo-generator.

jsc2018e050828

NASA Image and Video Library

2018-05-29

jsc2018e050828 - At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 56 prime crewmember Alexander Gerst of the European Space Agency takes a spin in a rotating chair May 29 to test his vestibular system as part of pre-launch activities. Gerst, Serena Aunon-Chancellor of NASA and Sergey Prokopyev of Roscosmos will launch June 6 from the Baikonur Cosmodrome in Kazakhstan on the Soyuz MS-09 spacecraft for a six-month mission on the International Space Station...NASA/Victor Zelentsov.

jsc2018e050829

NASA Image and Video Library

2018-05-29

jsc2018e050829 - At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 56 prime crewmember Serena Aunon-Chancellor of NASA takes a spin in a rotating chair May 29 to test her vestibular system as part of pre-launch activities. Aunon-Chancellor, Alexander Gerst of the European Space Agency and Sergey Prokopyev of Roscosmos will launch June 6 from the Baikonur Cosmodrome in Kazakhstan on the Soyuz MS-09 spacecraft for a six-month mission on the International Space Station...NASA/Victor Zelentsov.

jsc2017e043073

NASA Image and Video Library

2017-04-13

jsc2017e043073 (April 13, 2017) --- At the Cosmonaut Hotel crew quarters in Baikonur, Kazakhstan, Expedition 51 crewmember Jack Fischer of NASA takes a spin in a rotating chair to test his vestibular system April 13 as part of his pre-launch activities. Fischer and Fyodor Yurchikhin of the Russian Federal Space Agency (Roscosmos) will liftoff April 20 from the Baikonur Cosmodrome on the Soyuz MS-04 spacecraft for a four and a half month mission on the International Space Station. NASA/Victor Zelentsov

Method and system for measuring gate valve clearances and seating force

DOEpatents

Casada, D.A.; Haynes, H.D.; Moyers, J.C.; Stewart, B.K.

1996-01-30

Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner. 8 figs.

The effect of dynamic femoroacetabular impingement on pubic symphysis motion: a cadaveric study.

PubMed

Birmingham, Patrick M; Kelly, Bryan T; Jacobs, Robert; McGrady, Linda; Wang, Mei

2012-05-01

A link between femoroacetabular impingement and athletic pubalgia has been reported clinically. One proposed origin of athletic pubalgia is secondary to repetitive loading of the pubic symphysis, leading to instability and parasymphyseal tendon and ligament injury. Hypothesis/ The purpose of this study was to investigate the effect of simulated femoral-based femoroacetabular impingement on rotational motion at the pubic symphysis. The authors hypothesize that the presence of a cam lesion leads to increased relative symphyseal motion. Controlled laboratory study. Twelve hips from 6 fresh-frozen human cadaveric pelvises were used to simulate cam-type femoroacetabular impingement. The hips were held in a custom jig and maximally internally rotated at 90° of flexion and neutral adduction. Three-dimensional motion of the pubic symphysis was measured by a motion-tracking system for 2 states: native and simulated cam. Load-displacement plots were generated between the internal rotational torque applied to the hip and the responding motion in 3 anatomic planes of the pubic symphysis. As the hip was internally rotated, the motion at the pubic symphysis increased proportionally with the degrees of the rotation as well as the applied torque measured at the distal femur for both states. The primary rotation of the symphysis was in the transverse plane and on average accounted for more than 60% of the total rotation. This primary motion caused the anterior aspect of the symphyseal joint to open or widen, whereas the posterior aspect narrowed. At the torque level of 18.0 N·m, the mean transverse rotation in degrees was 0.89° ± 0.35° for the native state and 1.20° ± 0.41° for cam state. The difference between cam and the native groups was statistically significant (P < .03). Dynamic femoroacetabular impingement as caused by the presence of a cam lesion causes increased rotational motion at the pubic symphysis. Repetitive loading of the symphysis by cam impingement is thought to lead to increased symphyseal motion, which is one possible precursor to athletic pubalgia.

Isolated glenohumeral range of motion, excluding side-to-side difference in humeral retroversion, in asymptomatic high-school baseball players.

PubMed

Mihata, Teruhisa; Takeda, Atsushi; Kawakami, Takeshi; Itami, Yasuo; Watanabe, Chisato; Doi, Munekazu; Neo, Masashi

2016-06-01

Glenohumeral range of motion is correlated with shoulder capsular condition and is thus considered to be predictive of shoulder pathology. However, in throwing athletes, a side-to-side difference in humeral retroversion makes it difficult to evaluate capsular condition on the basis of glenohumeral range of motion measured by using the conventional technique. The purpose of this study was to measure isolated glenohumeral rotation, excluding side-to-side differences in humeral retroversion, in asymptomatic high-school baseball players. A total of 195 high-school baseball players (52 pitchers and 143 position players; median age, 16 years) and 20 high-school non-throwing athletes (median age, 16 years) without any shoulder symptoms were enroled in this study. Glenohumeral external and internal rotations were measured by using both a conventional technique and our ultrasound-assisted technique. This technique, neutral rotation, was standardized on the basis of the ultrasonographically visualized location of the bicipital groove to exclude side-to-side differences in humeral retroversion from the calculated rotation angle. Intra- and inter-observer agreements of rotational measurements were evaluated by using intra-class correlation coefficients (ICCs). Isolated glenohumeral rotation measurements, excluding side-to-side differences in humeral retroversion, demonstrated excellent intra-observer (ICC > 0.89) and inter-observer (ICC > 0.78) agreements. Isolated glenohumeral internal rotation was significantly less in the dominant shoulder than in the non-dominant shoulder in asymptomatic baseball players (P < 0.001). Isolated glenohumeral external rotation in baseball players was significantly greater than in non-throwing athletes (P < 0.05). In the baseball players, humeral torsion in the dominant shoulder was significantly greater than that in the non-dominant shoulder (P < 0.001), indicating that the retroversion angle was greater in dominant shoulders than in non-dominant shoulders. Isolated glenohumeral external and internal rotations can be measured with high intra- and inter-observer reliability with the exclusion of side-to-side differences in humeral retroversion. Capsular and muscular changes in the throwing shoulder may be better evaluated by using our ultrasound-assisted technique. Cross-sectional study, Level III.

The rotation-activity relation in M dwarfs

NASA Astrophysics Data System (ADS)

Newton, Elisabeth R.; Irwin, Jonathan; Charbonneau, David; Berlind, Perry L.; Calkins, Michael L.; Mink, Jessica D.

2017-01-01

Main sequence stars with masses below approximately 0.35 solar masses are fully-convective, and are expected to have a different type of magnetic dynamo than solar-type stars. Observationally, the dynamo mechanism can be probed through the relationship between rotation and magnetic activity, and the evolution of these properties. Though M dwarfs are the most common type of star in the galaxy, a lack of observational constraints at ages beyond 1 Gyr has hampered studies of the rotation-activity relation. To address this, we have made new measurements of rotation and magnetic activity in nearby, field-age M dwarfs. Combining our 386 rotation period measurements and 247 new optical spectra with data from the literature, we are able to probe the rotation-activity in M dwarfs with masses from 0.1 to 0.6 solar masses. We observe a threshold in the mass--period plane that separates active and inactive M dwarfs. The threshold coincides with the fast-period edge of the slowly rotating population, at approximately the rotation period at which an era of rapid rotational evolution appears to cease. We confirm that the activity of rapidly rotating M dwarfs maintains a saturated value. We have measured rotation periods as long as 140 days, allowing us to probe the unsaturated regime in detail. Our data show a clear power-law decay in relative H-alpha luminosity as a function Rossby number. We discuss implications for the magnetic dynamo mechanism.We acknowledge funding from the National Science Foundation, the David and Lucile Packard Foundation Fellowship for Science and Engineering, and the John Templeton Foundation. E.R.N. acknowledges support from the NSF through a Graduate Research Fellowship and an Astronomy and Astrophysics Postdoctoral Fellowship.

Cross-cultural challenges for assessing medical professionalism among clerkship physicians in a Middle Eastern country (Bahrain): feasibility and psychometric properties of multisource feedback.

PubMed

Al Ansari, Ahmed; Al Khalifa, Khalid; Al Azzawi, Mohamed; Al Amer, Rashed; Al Sharqi, Dana; Al-Mansoor, Anwar; Munshi, Fadi M

2015-01-01

We aimed to design, implement, and evaluate the feasibility and reliability of a multisource feedback (MSF) system to assess interns in their clerkship year in the Middle Eastern culture, the Kingdom of Bahrain. The study was undertaken in the Bahrain Defense Force Hospital, a military teaching hospital in the Kingdom of Bahrain. A total of 21 interns (who represent the total population of the interns for the given year) were assessed in this study. All of the interns were rotating through our hospital during their year-long clerkship rotation. The study sample consisted of nine males and 12 females. Each participating intern was evaluated by three groups of raters, eight medical intern colleagues, eight senior medical colleagues, and eight coworkers from different departments. A total of 21 interns (nine males and 12 females) were assessed in this study. The total mean response rates were 62.3%. A factor analysis was conducted that found that the data on the questionnaire grouped into three factors that counted for 76.4% of the total variance. These three factors were labeled as professionalism, collaboration, and communication. Reliability analysis indicated that the full instrument scale had high internal consistency (Cronbach's α 0.98). The generalizability coefficients for the surveys were estimated to be 0.78. Based on our results and analysis, we conclude that the MSF tool we used on the interns rotating in their clerkship year within our Middle Eastern culture provides an effective method of evaluation because it offers a reliable, valid, and feasible process.

A web-based simulation of a longitudinal clinic used in a 4-week ambulatory rotation: a cohort study

PubMed Central

Wong, Rene WG; Lochnan, Heather A

2009-01-01

Background Residency training takes place primarily on inpatient wards. In the absence of a resident continuity clinic, internal medicine residents rely on block rotations to learn about continuity of care. Alternate methods to introduce continuity of care are needed. Methods A web-based tool, Continuity of Care Online Simulations (COCOS), was designed for use in a one-month, postgraduate clinical rotation in endocrinology. It is an interactive tool that simulates the continuing care of any patient with a chronic endocrine disease. Twenty-three residents in internal medicine participated in a study to investigate the effects of using COCOS during a clinical rotation in endocrinology on pre-post knowledge test scores and self-assessment of confidence. Results Compared to residents who did the rotation alone, residents who used COCOS during the rotation had significantly higher improvements in test scores (% increase in pre-post test scores +21.6 [standard deviation, SD, 8.0] vs. +5.9 [SD 6.8]; p < .001). Test score improvements were most pronounced for less commonly seen conditions. There were no significant differences in changes in confidence. Residents rated COCOS very highly, recommending its use as a standard part of the rotation and throughout residency. Conclusion A stand-alone web-based tool can be incorporated into an existing clinical rotation to help residents learn about continuity of care. It has the most potential to teach residents about topics that are less commonly seen during a clinical rotation. The adaptable, web-based format allows the creation of cases for most chronic medical conditions. PMID:19187554

Rotation of intramedullary alignment rods affects distal femoral cutting plane in total knee arthroplasty.

PubMed

Maderbacher, Günther; Matussek, Jan; Keshmiri, Armin; Greimel, Felix; Baier, Clemens; Grifka, Joachim; Maderbacher, Hermann

2018-02-17

Intramedullary rods are widely used to align the distal femoral cut in total knee arthroplasty. We hypothesised that both coronal (varus/valgus) and sagittal (extension/flexion) cutting plane are affected by rotational changes of intramedullary femoral alignment guides. Distal femoral cuts using intramedullary alignment rods were simulated by means of a computer-aided engineering software in 4°, 6°, 8°, 10°, and 12° of valgus in relation to the femoral anatomical axis and 4° extension, neutral, as well as 4°, 8°, and 12° of flexion in relation to the femoral mechanical axis. This reflects the different angles between anatomical and mechanical axis in coronal and sagittal planes. To assess the influence of rotation of the alignment guide on the effective distal femoral cutting plane, all combinations were simulated with the rod gradually aligned from 40° of external to 40° of internal rotation. Rotational changes of the distal femoral alignment guides affect both the coronal and sagittal cutting planes. When alignment rods are intruded neutrally with regards to sagittal alignment, external rotation causes flexion, while internal rotation causes extension of the sagittal cutting plane. Simultaneously the coronal effect (valgus) decreases resulting in an increased varus of the cutting plane. However, when alignment rods are intruded in extension or flexion partly contradictory effects are observed. Generally the effect increases with the degree of valgus preset, rotation and flexion. As incorrect rotation of intramedullary alignment guides for distal femoral cuts causes significant cutting errors, exact rotational alignment is crucial. Coronal cutting errors in the distal femoral plane might result in overall leg malalignment, asymmetric extension gaps and subsequent sagittal cutting errors.

Reduced glenohumeral rotation, external rotation weakness and scapular dyskinesis are risk factors for shoulder injuries among elite male handball players: a prospective cohort study.

PubMed

Clarsen, Benjamin; Bahr, Roald; Andersson, Stig Haugsboe; Munk, Rikke; Myklebust, Grethe

2014-09-01

To determine whether rotator cuff strength, glenohumeral joint range of motion and scapular control are associated with shoulder injuries among elite male handball players. A total of 206 players in the Norwegian elite handball league for men were tested prior to the 2011-2012 season. Measures included: (1) glenohumeral internal and external rotation range of motion, (2) isometric internal rotation, external rotation and abduction strength and (3) assessment of scapular dyskinesis. Players were followed prospectively for the entire regular season (30 weeks), with shoulder problems registered bi-weekly using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A cumulative severity score was calculated for each player based on their questionnaire responses. This was used as the outcome measure in risk factor analyses. The average prevalence of shoulder problems throughout the season was 28% (95% CI 25% to 31%). The prevalence of substantial shoulder problems, defined as those leading to moderate or severe reductions in handball participation or performance, or to time loss, was 12% (95% CI 11% to 13%). Significant associations were found between obvious scapular dyskinesis (OR 8.41, 95% CI 1.47 to 48.1, p<0.05), total rotational motion (OR 0.77 per 5° change, 95% CI 0.56 to 0.995, p<0.05) and external rotation strength (OR 0.71 per 10 Nm change, 95% CI 0.44 to 0.99, p<0.05) and shoulder injury. Injury prevention programmes should incorporate interventions aimed at improving glenohumeral rotational range of motion, external rotation strength and scapular control. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Prediction of Tibial Rotation Pathologies Using Particle Swarm Optimization and K-Means Algorithms.

PubMed

Sari, Murat; Tuna, Can; Akogul, Serkan

2018-03-28

The aim of this article is to investigate pathological subjects from a population through different physical factors. To achieve this, particle swarm optimization (PSO) and K-means (KM) clustering algorithms have been combined (PSO-KM). Datasets provided by the literature were divided into three clusters based on age and weight parameters and each one of right tibial external rotation (RTER), right tibial internal rotation (RTIR), left tibial external rotation (LTER), and left tibial internal rotation (LTIR) values were divided into three types as Type 1, Type 2 and Type 3 (Type 2 is non-pathological (normal) and the other two types are pathological (abnormal)), respectively. The rotation values of every subject in any cluster were noted. Then the algorithm was run and the produced values were also considered. The values of the produced algorithm, the PSO-KM, have been compared with the real values. The hybrid PSO-KM algorithm has been very successful on the optimal clustering of the tibial rotation types through the physical criteria. In this investigation, Type 2 (pathological subjects) is of especially high predictability and the PSO-KM algorithm has been very successful as an operation system for clustering and optimizing the tibial motion data assessments. These research findings are expected to be very useful for health providers, such as physiotherapists, orthopedists, and so on, in which this consequence may help clinicians to appropriately designing proper treatment schedules for patients.

Rotational Spectrum of Sarin.

PubMed

Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

2001-05-01

As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C(4)H(10)FO(2)P) was observed in the rotationally cold (T(rot)<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1sigma), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm(-1). Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G(**) level of theory is consistent with our experimental findings. Copyright 2001 Academic Press.

Rotational Spectrum of Sarin

NASA Astrophysics Data System (ADS)

Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

2001-05-01

As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C4H10FO2P) was observed in the rotationally cold (Trot<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1σ), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm-1. Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G** level of theory is consistent with our experimental findings.

Probing Vitamine C, Aspirin and Paracetamol in the Gas Phase: High Resolution Rotational Studies

NASA Astrophysics Data System (ADS)

Mata, S.; Cabezas, C.; Varela, M.; Pena, I.; Nino, A.; López, J. C.; Alonso, J. L.; Grabow, J.-U.

2011-06-01

A solid sample of Vitamin C (m.p. 190°C) vaporized by laser ablation has been investigated in gas phase and characterized through their rotational spectra. Two spectroscopy techniques has been used to obtain the spectra: a new design of broadband chirped pulse Fourier transform microwave spectroscopy with in-phase/quadrature-phase-modulation passage-acquired-coherence technique (IMPACT) and conventional laser ablation molecular beam Fourier transform microwave spectroscopy (LA-MB-FTMW). Up to now, two low-energy conformer have been observed and their rotational constants determined. Ab initio calculations at the MP2/6-311++G (d,p) level of theory predicted rotational constants which helped us to identify these conformers unequivocally. Among the molecules to benefit from the LA-MB-FTMW technique there are common important drugs never observed in the gas phase through rotational spectroscopy. We present here the results on acetyl salicylic acid and acetaminophen (m.p. 136°C), commonly known as aspirin and paracetamol respectively. We have observed two stable conformers of aspirin and two for paracetamol. The internal rotation barrier of the methyl group in aspirin has been determined for both conformers from the analysis of the A-E splittings due to the coupling of internal and overall rotation. J. L. Alonso, C. Pérez, M. E. Sanz, J. C. López, S. Blanco, Phys. Chem. Chem. Phys. 11,617-627 (2009)and references therein

Gender-related differences in lower limb alignment, range of joint motion, and the incidence of sports injuries in Japanese university athletes.

PubMed

Mitani, Yasuhiro

2017-01-01

[Purpose] To investigate the gender-related differences in lower limb alignment, range of joint motion, and history of lower limb sports injuries in Japanese university athletes. [Subjects and Methods] The subjects were 224 Japanese university athletes (154 males and 70 females). The quadriceps angle (Q-angle), arch height index, and ranges of internal and external rotation of the hip joints were measured. History of lower limb sports injury was surveyed using a questionnaire. [Results] Females had a significantly higher Q-angle and hip joint internal rotation angle and a significantly lower arch height index than males. The survey revealed that a significantly higher proportion of females had a history of lower limb sports injuries, and that the proportion of those with a history of foot/ankle injuries was particularly high. [Conclusion] These results suggested that females experience more lower limb sports injuries than males, and that a large proportion of these injuries involve the foot/ankle. Reduced lower limb alignment and increased range of joint motion in females may be risk factors for injury because they lead to increased physical stress being exerted on the lower legs during sporting activities.

Collective rotations of active particles interacting with obstacles

NASA Astrophysics Data System (ADS)

Mokhtari, Zahra; Aspelmeier, Timo; Zippelius, Annette

2017-10-01

We consider active particles in a heterogeneous medium, modeled by static, random obstacles. In accordance with the known tendency of active particles to cluster, we observe accumulation and crystallization of active particles around the obstacles which serve as nucleation sites. In the limit of high activity, the crystals start to rotate spontaneously, resembling a rotating rigid body. We trace the occurrence of these oscillations to the enhanced attraction of particles whose orientation points along the rotational velocity as compared to those whose orientation points in the opposite direction.

Internal desynchronization in a model of night-work by forced activity in rats.

PubMed

Salgado-Delgado, R; Angeles-Castellanos, M; Buijs, M R; Escobar, C

2008-06-26

Individuals engaged in shift- or night-work show disturbed diurnal rhythms, out of phase with temporal signals associated to the light/dark (LD) cycle, resulting in internal desynchronization. The mechanisms underlying internal desynchrony have been mainly investigated in experimental animals with protocols that induce phase shifts of the LD cycle and thus modify the activity of the suprachiasmatic nucleus (SCN). In this study we developed an animal model of night-work in which the light-day cycle remained stable and rats were required to be active in a rotating wheel for 8 h daily during their sleeping phase (W-SP). This group was compared with rats that were working in the wheel during their activity phase (W-AP) and with undisturbed rats (C). We provide evidence that forced activity during the sleeping phase (W-SP group) alters not only activity, but also the temporal pattern of food intake. In consequence W-SP rats showed a loss of glucose rhythmicity and a reversed rhythm of triacylglycerols. In contrast W-AP rats did not show such changes and exhibited metabolic rhythms similar to those of the controls. The three groups exhibited the nocturnal corticosterone increase, in addition the W-SP and W-AP groups showed increase of plasma corticosterone associated with the start of the working session. Forced activity during the sleep phase did not modify SCN activity characterized by the temporal patterns of PER1 and PER2 proteins, which remained in phase with the LD cycle. These observations indicate that a working regimen during the sleeping period elicits internal desynchronization in which activity combined with feeding uncouples metabolic functions from the biological clock which remains fixed to the LD cycle. The present data suggest that in the night worker the combination of work and eating during working hours may be the cause of internal desynchronization.

Range of Hip Joint Motion Is Correlated With MRI-Verified Cam Deformity in Adolescent Elite Skiers

PubMed Central

Agnvall, Cecilia; Swärd Aminoff, Anna; Todd, Carl; Jonasson, Pall; Thoreson, Olof; Swärd, Leif; Karlsson, Jon; Baranto, Adad

2017-01-01

Background: Radiologically verified cam-type femoroacetabular impingement (FAI) has been shown to correlate with reduced internal rotation, reduced passive hip flexion, and a positive anterior impingement test. Purpose: To validate how a clinical examination of the hip joint correlates with magnetic resonance imaging (MRI)–verified cam deformity in adolescents. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The sample group consisted of 102 adolescents with the mean age 17.7 ± 1.4 years. The hip joints were examined using MRI for measurements of the presence of cam (α-angle ≥55°) and clinically for range of motion (ROM) in both supine and sitting positions. The participants were divided into a cam and a noncam group based on the results of the MRI examination. Passive hip flexion, internal rotation, anterior impingement, and the FABER (flexion, abduction, and external rotation) test were used to test both hips in the supine position. With the participant sitting, the internal/external rotation of the hip joint was measured in 3 different positions of the pelvis (neutral, maximum anteversion, and retroversion) and lumbar spine (neutral, maximum extension, and flexion). Results: Differences were found between the cam and noncam groups in terms of the anterior impingement test (right, P = .010; left, P = .006), passive supine hip flexion (right: mean, 5°; cam, 117°; noncam, 122° [P = .05]; and left: mean, 8.5°; cam, 116°; noncam, 124.5° [P = .001]), supine internal rotation (right: mean, 4.9°; cam, 24°; noncam, 29° [P = .022]; and left: mean, 4.8°; cam, 26°; noncam, 31° [P = .028]), sitting internal rotation with the pelvis and lumbar spine in neutral (right: mean, 7.95°; cam, 29°; noncam, 37° [P = .001]; and left: mean, 6.5°; cam, 31.5°; noncam, 38° [P = .006]), maximum anteversion of the pelvis and extension of the lumbar spine (right: mean, 5.2°; cam, 20°; noncam, 25° [P = .004]; and left: mean, 5.85°; cam, 20.5; noncam, 26.4° [P = .004]), and maximum retroversion of the pelvis and flexion of the spine (right: mean, 8.4°; cam, 32.5°; noncam, 41° [P = .001]; and left: mean, 6.2°; cam, 36°; noncam, 42.3° [P = .012]). The cam group had reduced ROM compared with the noncam group in all clinical ROM measures. Conclusion: The presence of cam deformity on MRI correlates with reduced internal rotation in the supine and sitting positions, passive supine hip flexion, and the impingement test in adolescents. PMID:28695136

An In Vitro Robotic Assessment of the Anterolateral Ligament, Part 2: Anterolateral Ligament Reconstruction Combined With Anterior Cruciate Ligament Reconstruction.

PubMed

Nitri, Marco; Rasmussen, Matthew T; Williams, Brady T; Moulton, Samuel G; Cruz, Raphael Serra; Dornan, Grant J; Goldsmith, Mary T; LaPrade, Robert F

2016-03-01

Recent biomechanical studies have demonstrated that an extra-articular lateral knee structure, most recently referred to as the anterolateral ligament (ALL), contributes to overall rotational stability of the knee. However, the effect of anatomic ALL reconstruction (ALLR) in the setting of anterior cruciate ligament (ACL) reconstruction (ACLR) has not been biomechanically investigated or validated. The purpose of this study was to investigate the biomechanical function of anatomic ALLR in the setting of a combined ACL and ALL injury. More specifically, this investigation focused on the effect of ALLR on resultant rotatory stability when performed in combination with concomitant ACLR. It was hypothesized that ALLR would significantly reduce internal rotation and axial plane translation laxity during a simulated pivot-shift test compared with isolated ACLR. Controlled laboratory study. Ten fresh-frozen cadaveric knees were evaluated with a 6 degrees of freedom robotic system. Knee kinematics were evaluated with simulated clinical examinations including a simulated pivot-shift test consisting of coupled 10-N·m valgus and 5-N·m internal rotation torques, a 5-N·m internal rotation torque, and an 88-N anterior tibial load. Kinematic differences between ACLR with an intact ALL, ACLR with ALLR, and ACLR with a deficient ALL were compared with the intact state. Single-bundle ACLR tunnels and ALLR tunnels were placed anatomically according to previous quantitative anatomic attachment descriptions. Combined anatomic ALLR and ACLR significantly improved the rotatory stability of the knee compared with isolated ACLR in the face of a concurrent ALL deficiency. During a simulated pivot-shift test, ALLR significantly reduced internal rotation and axial plane tibial translation when compared with ACLR with an ALL deficiency. Isolated ACLR for the treatment of a combined ACL and ALL injury was not able to restore stability of the knee, resulting in a significant increase in residual internal rotation laxity. ALLR did not affect anterior tibial translation; no significant differences were observed between the varying ALL conditions with ACLR except between ACLR with an intact ALL and ACLR with a deficient ALL at 0° of flexion. In the face of a combined ACL and ALL deficiency, concurrent ACLR and ALLR significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL. Significant increases in residual internal rotation and laxity during the pivot-shift test may exist in both acute and chronic settings of an ACL deficiency and in patients treated with isolated ACLR for a combined ACL and ALL deficiency. For this subset of patients, surgical treatment of the ALL, in addition to ACLR, should be considered to restore knee stability. © 2016 The Author(s).

On searching applicants for mechanism of solar-lithosphere relations

NASA Astrophysics Data System (ADS)

Kairatkyzy, Dina; Andreyev, Alexey; Zhumabayeva, Saltanat; Seraliyev, Alibek

2016-04-01

It is actively discussed at present a question on possible influence of solar activity (high-speed solar wind streams bearing the "frozen" magnetic field lines of the Sun) on the stress status of the lithosphere and, consequently, on the Earth's seismic activity (e.g. Zhang, 1998, Acta Seismologica Sinica; Khachikyan et al., EGU2016-2754-1; IUGG2015-3132). There are at least two ideas on possible applicants for physical mechanism of solar-lithosphere relations: (i) - the muons of cosmic rays, which can penetrate the Earth's crust to a depth of at least the first ten kilometers and in tense seismic environment generate nuclear-electromagnetic cascade which energy can be a trigger of earthquake (Tsarev and Chechin, 1988, Preprint № 179, Physical Institute after Lebedev, Moscow); (ii) - the geomagnetic storms (Sobolev et al., 1998, Physics of the Earth #7) when the high-frequency oscillations of the geomagnetic field during the main phase of the storm generate significant induction currents which electric energy entering into the crust can be converted into mechanical energy increasing the stress status of the lithosphere (Sobolev and Demin, Mechano-electric phenomena into the Earth. M . Nauka. 1980). Besides this, among the possible cosmogenic factors changing the stress state of the lithosphere, could be the variation of the angular velocity of rotation of the Earth (e.g. Bostrom, 2000. Tectonic consequence of the Earth's Rotation), if it depends on solar activity variations. More of 50 years ago, Munk and Donald (The Rotation of the Earth, Cambrige University Press, 1960) suggested that the interaction between solar wind and geomagnetic field would probably influence the short period variation of angular velocity of the Earth. In this work, we check up this suggestion on the base of very precise data on the length of day (LOD) from 1986 to the present, which are presented by the International Earth Rotation and Reference Systems Service (IERS). Using the methods of spectral analysis, we studied the temporal variations in amplitudes of short period variation of the LOD and compared them with the temporal variations of the solar activity data. The obtained results are presented in this report.

Effects of internal structure on equilibrium of field-reversed configuration plasma sustained by rotating magnetic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yambe, Kiyoyuki; Inomoto, Michiaki; Okada, Shigefumi

The effects of an internal structure on the equilibrium of a field-reversed configuration (FRC) plasma sustained by rotating magnetic field is investigated by using detailed electrostatic probe measurements in the FRC Injection Experiment apparatus [S. Okada, et al., Nucl. Fusion. 45, 1094 (2005)]. An internal structure installed axially on the geometrical axis, which simulates Ohmic transformer or external toroidal field coils on the FRC device, brings about substantial changes in plasma density profile. The internal structure generates steep density-gradients not only on the inner side but on the outer side of the torus. The radial electric field is observed tomore » sustain the ion thermal pressure-gradient in the FRC without the internal structure; however, the radial electric field is not sufficient to sustain the increased ion thermal pressure-gradient in the FRC with the internal structure. Spontaneously driven azimuthal ion flow will be accountable for the imbalance of the radial pressure which is modified by the internal structure.« less

Landing strategies focusing on the control of tibial rotation in the initial contact period of one-leg forward hops.

PubMed

Chen, W-L; Chen, Y-T; Huang, S-Y; Yang, C-Y; Wu, C-D; Chang, C-W

2017-08-01

Anterior cruciate ligament (ACL) reconstruction (ACLR) surgeries successfully restore anterior tibial translation but not tibial rotation. This study aimed to explore landing strategies focusing on the control of tibial rotation at landing when the ACL is most vulnerable. Three groups of male subjects (50 ACLRs, 26 basketball players, and 31 controls) participated in one-leg forward hop tests for determining the tibial rotatory landing strategies adopted during the initial landing phase. The differences in knee kinematics and muscle activities between internal and external tibial rotatory (ITR, ETR) landing strategies were examined. A higher proportion of basketball players (34.6%) were found to adopt ITR strategies (controls: 6.5%), exhibiting significantly greater hopping distance and knee strength. After adjusting for hopping distance, subjects adopting ITR strategies were found to hop faster with straighter knees at foot contact and with greater ITR and less knee adduction angular displacement during the initial landing phase. However, significantly greater angular displacement in knee flexion, greater medial hamstring activities, and greater co-contraction index of hamstrings and medial knee muscles were also found during initial landing. Our results support the importance of the recruitments of medial hamstrings or the local co-contraction in assisting the rotatory control of the knee during initial landing for avoiding ACL injuries. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mechanisms of Shoulder Range of Motion Deficits in Asymptomatic Baseball Players.

PubMed

Bailey, Lane B; Shanley, Ellen; Hawkins, Richard; Beattie, Paul F; Fritz, Stacy; Kwartowitz, David; Thigpen, Charles A

2015-11-01

Shoulder range of motion (ROM) deficits have been identified as injury risk factors among baseball athletes. Despite the knowledge surrounding these risk factors, there is a lack of consensus regarding the specific tissues responsible for these deficits in ROM. The purpose of this study was to elucidate the primary mechanisms of posterior shoulder tightness (capsular, musculotendinous, bony) by examining the tissue responses that occur with the application of an acute intervention in baseball players with ROM deficits. The hypothesis was that posterior rotator cuff stiffness, not glenohumeral joint mobility, would be primarily responsible for ROM gains observed within an acute treatment setting. Controlled laboratory study. Through use of ultrasound elastography, electromagnetic motion analysis, and ultrasound imaging, posterior rotator cuff stiffness, glenohumeral joint translation, and humeral torsion were examined in 60 asymptomatic baseball players (age, mean ± SD, 19 ± 2 years) with shoulder ROM deficits. Tissue mechanisms were examined concurrently, with the ROM gains elicited by an acute application of instrument-assisted soft tissue mobilization plus self-stretching (n = 30) versus self-stretching only (n = 30). Separate 3-way analyses of variance (group × arm × time) and linear regression analyses were used to determine the treatment effects and relationships between tissue mechanisms and ROM gains. ROM gains were associated with decreases in rotator cuff stiffness (internal rotation: r = 0.35, P = .034; horizontal adduction: r = 0.44, P = .008) and increased humeral retrotorsion (internal rotation: r = -0.35, P = .034), not joint translation (P > .05). Players receiving instrument-assisted soft tissue mobilization plus stretching displayed greater shoulder ROM gains (internal rotation, +5° ± 2° [P = .010]; total arc of motion, +8° ± 6° [P = .010]; horizontal adduction, +7° ± 2° [P = .004]; and decreased posterior rotator cuff stiffness, -0.2 ± 0.3 kPa [P = .050]) compared with players receiving self-stretching alone. Decreases in rotator cuff stiffness were associated with acute ROM gains in baseball players. The study results show that changes in rotator cuff stiffness, not glenohumeral joint mobility or humeral torsion, are most likely associated with the ROM deficits observed in adolescent baseball players. Reducing rotator cuff stiffness may be beneficial in improving the ROM deficits associated with injury risk in overhead athletes. © 2015 The Author(s).

The effects of age and type of carrying task on lower extremity kinematics

PubMed Central

Gillette, Jason C.; Stevermer, Catherine A.; Miller, Ross H.; Meardon, Stacey A.; Schwab, Charles V.

2009-01-01

The purpose of this study was to determine the effects of age, load amount, and load symmetry on lower extremity kinematics during carrying tasks. Forty-two participants in four age groups (8-10 years, 12-14 years, 15-17 years, and adults) carried loads of 0%, 10%, and 20% body weight (BW) in large or small buckets unilaterally and bilaterally. Reflective markers were tracked to determine total joint ROM and maximum joint angles during the stance phase of walking. Maximum hip extension, hip adduction, and hip internal rotation angles were significantly greater for each of the child/adolescent age groups as compared to adults. In addition, maximum hip internal rotation angles significantly increased when carrying a 20% BW load. The observation that the 8-10 year old age group carried the lightest absolute loads and still displayed the highest maximum hip internal rotation angles suggests a particular necessity in setting carrying guidelines for the youngest children. PMID:20191410

Shoulder arthrodesis in adult brachial plexus injury: what is the optimal position?

PubMed

Sousa, R; Pereira, A; Massada, M; Trigueiros, M; Lemos, R; Silva, C

2011-09-01

Brachial plexus injuries are a major indication for shoulder arthrodesis. However, there is no consensus concerning the optimal position of the glenohumeral joint for fusion. Between 1997 and 2008, 19 shoulder arthrodeses were performed using pelvic reconstruction plates. The radiographic and functional characteristics of 13 patients of mean age 46 years were examined at a mean of 101 months after arthrodesis. Arthrodeses showed 30° mean angle of abduction, 32° forward flexion and 44° internal rotation of the humerus with respect to the scapula. Abduction >35° and forward flexion ≥30° seem to offer slightly better functional results. Internal rotation ≤45° significantly relates to better ability of the hand to reach the face (p = 0.012). Neither abduction >35° nor forward flexion ≥30° showed a higher prevalence of periscapular pain. Abduction around 35° and forward flexion around 30° are needed for good functional results. Internal rotation should not exceed 45°.

ARTHROSCOPIC TREATMENT OF FEMOROACETABULAR IMPINGEMENT

PubMed Central

Polesello, Giancarlo C.; Queiroz, Marcelo C.; Ono, Nelson K.; Honda, Emerson K.; Guimarāes, Rodrigo P; Junior, Walter Ricioli

2015-01-01

Objective: The purpose of this study is to evaluate the short-term follow-up results of arthroscopic treatment of femoroacetabular impingement. Our hypothesis is that arthroscopic treatment results are favorable. Methods: Between August 2003 and August 2007, 28 hips had femoroacetabular impingement treated by hip arthroscopy. The mean age was 34 years, with mean follow-up period of 27 months. Clinical results were graded with the modified Harris hip score, which was measured pre- and postoperatively. Patients had also their internal rotation analyzed. These parameters were calculated by using Wilcoxon's t test for analysis of nonparametric paired samples performed. Results: The mean preoperative Harris Hip Score was 54.2, improving to 94.8 postoperatively (p<0,001). The mean increase was 37.5 points. We had 4 good results (15%) and 24 excellent results (85%). Preoperatively, the patients had a mean internal rotation of 17°, and, postoperatively, 36°. The average internal rotation increase was 19° (p<0,001). Conclusions: The arthroscopic treatment of femoroacetabular impingement presents satisfactory results. PMID:27004177

The pulsation-rotation interaction: Greatest hits and the B-side

NASA Astrophysics Data System (ADS)

Townsend, Rich

2014-02-01

It has long been known that rotation can have an appreciable impact on stellar pulsation - by modifying the usual p and g modes found in the non-rotating case, and by introducing new classes of modes. However, it's only relatively recently that advances in numerical simulations and complementary theoretical treatments have enabled us to model these phenomena in any great detail. In this talk I'll review highlights in this area (the `Greatest Hits'), before considering the flip side (or the `B-side', for those of us old enough to remember vinyl records) of the pulsation-rotation interaction: how pulsation can itself influence internal rotation profiles.

Does arthroscopic rotator cuff repair improve patients' activity levels?

PubMed

Baumgarten, Keith M; Chang, Peter S; Dannenbring, Tasha M; Foley, Elaine K

2018-06-04

Rotator cuff repair decreases pain, improves range of motion, and increases strength. Whether these improvements translate to an improvement in a patient's activity level postoperatively remains unknown. The Shoulder Activity Level is a valid and reliable outcomes survey that can be used to measure a patient's shoulder-specific activity level. Currently, there are no studies that examine the effect of rotator cuff repair on shoulder activity level. Preoperative patient-determined outcomes scores collected prospectively on patients undergoing rotator cuff repair were compared with postoperative scores at a minimum of 2 years. These scores included the Shoulder Activity Level, Western Ontario Rotator Cuff Index, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Single Assessment Numeric Evaluation, and simple shoulder test. Inclusion criteria were patients undergoing arthroscopic rotator cuff repair. Included were 281 shoulders from 273 patients with a mean follow-up of 3.7 years. The postoperative median Western Ontario Rotator Cuff Index (42 vs. 94), American Shoulder and Elbow Surgeons (41 vs. 95), Single Assessment Numeric Evaluation (30 vs. 95), and simple shoulder test (4 vs. 11) scores were statistically significantly improved compared with preoperative scores (P < .0001). The postoperative median Shoulder Activity Level score decreased compared with the preoperative score (12 vs. 11; P < .0001). Patients reported a statistically significant deterioration of their Shoulder Activity Level score after rotator cuff repair compared with their preoperative scores, although disease-specific and joint-specific quality of life scores all had statistically significantly improvement. This study suggests that patients generally have (1) significant improvements in their quality of life and (2) small deteriorations in activity level after arthroscopic rotator cuff repair. Copyright © 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

ISS Node-1 and PMA-1 rotated in KSC's SSPF

NASA Technical Reports Server (NTRS)

1997-01-01

The International Space Station's Node 1 and Pressurized Mating Adapter-1 (PMA-1) are rotated by workers in KSC's Space Station Processing Facility. The node is rotated to provide access to different areas of the flight element for processing. Here, the node is rotated to provide access for the installation of heat pipe radiators and a flight computer. The node is scheduled to launch into space on STS-88, slated for a July 9 liftoff at 1:11 p.m. from KSC's Launch Pad 39B.

Instruments to assess patients with rotator cuff pathology: a systematic review of measurement properties.

PubMed

Longo, Umile Giuseppe; Saris, Daniël; Poolman, Rudolf W; Berton, Alessandra; Denaro, Vincenzo

2012-10-01

The aims of this study were to obtain an overview of the methodological quality of studies on the measurement properties of rotator cuff questionnaires and to describe how well various aspects of the design and statistical analyses of studies on measurement properties are performed. A systematic review of published studies on the measurement properties of rotator cuff questionnaires was performed. Two investigators independently rated the quality of the studies using the Consensus-based Standards for the selection of health Measurement Instruments checklist. This checklist was developed in an international Delphi consensus study. Sixteen studies were included, in which two measurement instruments were evaluated, namely the Western Ontario Rotator Cuff Index and the Rotator Cuff Quality-of-Life Measure. The methodological quality of the included studies was adequate on some properties (construct validity, reliability, responsiveness, internal consistency, and translation) but need to be improved on other aspects. The most important methodological aspects that need to be developed are as follows: measurement error, content validity, structural validity, cross-cultural validity, criterion validity, and interpretability. Considering the importance of adequate measurement properties, it is concluded that, in the field of rotator cuff pathology, there is room for improvement in the methodological quality of studies measurement properties. II.

Dynamically generated patterns in dense suspensions of active filaments

NASA Astrophysics Data System (ADS)

Prathyusha, K. R.; Henkes, Silke; Sknepnek, Rastko

2018-02-01

We use Langevin dynamics simulations to study dynamical behavior of a dense planar layer of active semiflexible filaments. Using the strength of active force and the thermal persistence length as parameters, we map a detailed phase diagram and identify several nonequilibrium phases in this system. In addition to a slowly flowing melt phase, we observe that, for sufficiently high activity, collective flow accompanied by signatures of local polar and nematic order appears in the system. This state is also characterized by strong density fluctuations. Furthermore, we identify an activity-driven crossover from this state of coherently flowing bundles of filaments to a phase with no global flow, formed by individual filaments coiled into rotating spirals. This suggests a mechanism where the system responds to activity by changing the shape of active agents, an effect with no analog in systems of active particles without internal degrees of freedom.

A Hybrid Program for Fitting Rotationally Resolved Spectra of Floppy Molecules with One Large-Amplitude Rotatory Motion and One Large-Amplitude Oscillatory Motion

PubMed Central

Kleiner, Isabelle; Hougen, Jon T.

2015-01-01

A new hybrid-model fitting program for methylamine-like molecules has been developed, based on an effective Hamiltonian in which the ammonia-like inversion motion is treated using a tunneling formalism, while the internal-rotation motion is treated using an explicit kinetic energy operator and potential energy function. The Hamiltonian in the computer program is set up as a 2×2 partitioned matrix, where each diagonal block contains a traditional torsion-rotation Hamiltonian (as in the earlier program BELGI), and the two off-diagonal blocks contain tunneling terms. This hybrid formulation permits the use of the permutation-inversion group G6 (isomorphic to C3v) for terms in the two diagonal blocks, but requires G12 for terms in the off-diagonal blocks. The first application of the new program is to 2-methylmalonaldehyde. Microwave data for this molecule were previously fit using an all-tunneling Hamiltonian formalism to treat both large-amplitude-motions. For 2-methylmalonaldehyde, the hybrid program achieves the same quality of fit as was obtained with the all-tunneling program, but fits with the hybrid program eliminate a large discrepancy between internal rotation barriers in the OH and OD isotopologs of 2-methylmalonaldehyde that arose in fits with the all-tunneling program. This large isotopic shift in internal rotation barrier is thus almost certainly an artifact of the all-tunneling model. Other molecules for application of the hybrid program are mentioned. PMID:26439709

Single-molecule Analysis of Inhibitory Pausing States of V1-ATPase*

PubMed Central

Uner, Naciye Esma; Nishikawa, Yoshihiro; Okuno, Daichi; Nakano, Masahiro; Yokoyama, Ken; Noji, Hiroyuki

2012-01-01

V1-ATPase, the hydrophilic V-ATPase domain, is a rotary motor fueled by ATP hydrolysis. Here, we found that Thermus thermophilus V1-ATPase shows two types of inhibitory pauses interrupting continuous rotation: a short pause (SP, 4.2 s) that occurred frequently during rotation, and a long inhibitory pause (LP, >30 min) that terminated all active rotations. Both pauses occurred at the same angle for ATP binding and hydrolysis. Kinetic analysis revealed that the time constants of inactivation into and activation from the SP were too short to represent biochemically predicted ADP inhibition, suggesting that SP is a newly identified inhibitory state of V1-ATPase. The time constant of inactivation into LP was 17 min, consistent with one of the two time constants governing the inactivation process observed in bulk ATPase assay. When forcibly rotated in the forward direction, V1 in LP resumed active rotation. Solution ADP suppressed the probability of mechanical activation, suggesting that mechanical rotation enhanced inhibitory ADP release. These features were highly consistent with mechanical activation of ADP-inhibited F1, suggesting that LP represents the ADP-inhibited state of V1-ATPase. Mechanical activation largely depended on the direction and angular displacement of forced rotation, implying that V1-ATPase rotation modulates the off rate of ADP. PMID:22736762

Massive star formation by accretion. II. Rotation: how to circumvent the angular momentum barrier?

NASA Astrophysics Data System (ADS)

Haemmerlé, L.; Eggenberger, P.; Meynet, G.; Maeder, A.; Charbonnel, C.; Klessen, R. S.

2017-06-01

Context. Rotation plays a key role in the star-formation process, from pre-stellar cores to pre-main-sequence (PMS) objects. Understanding the formation of massive stars requires taking into account the accretion of angular momentum during their PMS phase. Aims: We study the PMS evolution of objects destined to become massive stars by accretion, focusing on the links between the physical conditions of the environment and the rotational properties of young stars. In particular, we look at the physical conditions that allow the production of massive stars by accretion. Methods: We present PMS models computed with a new version of the Geneva Stellar Evolution code self-consistently including accretion and rotation according to various accretion scenarios for mass and angular momentum. We describe the internal distribution of angular momentum in PMS stars accreting at high rates and we show how the various physical conditions impact their internal structures, evolutionary tracks, and rotation velocities during the PMS and the early main sequence. Results: We find that the smooth angular momentum accretion considered in previous studies leads to an angular momentum barrier and does not allow the formation of massive stars by accretion. A braking mechanism is needed in order to circumvent this angular momentum barrier. This mechanism has to be efficient enough to remove more than two thirds of the angular momentum from the inner accretion disc. Due to the weak efficiency of angular momentum transport by shear instability and meridional circulation during the accretion phase, the internal rotation profiles of accreting stars reflect essentially the angular momentum accretion history. As a consequence, careful choice of the angular momentum accretion history allows circumvention of any limitation in mass and velocity, and production of stars of any mass and velocity compatible with structure equations.

Effect of a 6-week strengthening program on shoulder and scapular-stabilizer strength and scapular kinematics in division I collegiate swimmers.

PubMed

Hibberd, Elizabeth E; Oyama, Saki; Spang, Jeffrey T; Prentice, William; Myers, Joseph B

2012-08-01

Shoulder injuries are common in swimmers because of the demands of the sport. Muscle imbalances frequently exist due to the biomechanics of the sport, which predispose swimmers to injury. To date, an effective shoulder-injury-prevention program for competitive swimmers has not been established. To assess the effectiveness of a 6-wk strengthening and stretching intervention program on improving glenohumeral and scapular muscle strength and scapular kinematics in collegiate swimmers. Randomized control trial. University biomechanics research laboratory. Forty-four Division I collegiate swimmers. The intervention program was completed 3 times per week for 6 wk. The program included strengthening exercises completed using resistance tubing-scapular retraction (Ts), scapular retraction with upward rotation (Ys), scapular retraction with downward rotation (Ws), shoulder flexion, low rows, throwing acceleration and deceleration, scapular punches, shoulder internal rotation at 90° abduction, and external rotation at 90° abduction-and 2 stretching exercises: corner stretch and sleeper stretch. Scapular kinematics and glenohumeral and scapular muscle strength assessed preintervention and postintervention. There were no significant between-groups differences in strength variables at pre/post tests, although shoulder-extension and internal-rotation strength significantly increased in all subjects regardless of group assignment. Scapular kinematic data revealed increased scapular internal rotation, protraction, and elevation in all subjects at posttesting but no significant effect of group on the individual kinematic variables. The current strengthening and stretching program was not effective in altering strength and scapular kinematic variables but may serve as a framework for future programs. Adding more stretching exercises, eliminating exercises that overlap with weight-room training and swim training, and timing of implementation may yield a more beneficial program for collegiate swimmers.

The effect of pain on hip and knee kinematics during running in females with chronic patellofemoral pain.

PubMed

Noehren, Brian; Sanchez, Zack; Cunningham, Tom; McKeon, Patrick Owen

2012-07-01

Despite the growing recognition of the role of abnormal hip and knee mechanics in patellofemoral pain (PFP), few studies have assessed if or how these mechanics change when the person experiences pain while running. Therefore, the purpose of this study was to determine if the development of pain while running resulted in altered hip and knee kinematics in female runners with PFP as compared to healthy female runners. Thirty female runners (15 PFP, 15 controls) participated in an instrumented gait analysis while running for 30 min at a self-selected pace. Pain and fatigue were recorded every minute while participants ran. Variables of interest included peak hip adduction, hip internal rotation, knee abduction, knee external rotation, pain, and fatigue. There were significant group by pain interactions for hip adduction (p<0.01) and hip internal rotation (p<0.01). The healthy group, who did not develop pain had significant increases in both motions compared to the PFP group, who did develop pain. There was also a trend toward less knee external rotation in the PFP group in presence of pain (p=0.059). No differences were found for knee abduction (p=0.32). A group main effect was found for hip internal rotation (p=0.008) in which the PFP group had significantly larger values. Runners with PFP did not alter their hip mechanics over the course of the run. This may have resulted in repetitive stress to the same aspect of the patellofemoral joint and contributed to the initial development of pain. However, the PFP group did attempt to make a compensation once in pain by reducing knee external rotation. Copyright © 2012 Elsevier B.V. All rights reserved.

The relationship between latissimus dorsi stiffness and altered scapular kinematics among asymptomatic collegiate swimmers.

PubMed

Laudner, Kevin G; Williams, Jeffrey G

2013-02-01

To determine the strength of the relationship between latissimus dorsi stiffness and altered scapular kinematics among swimmers. Cross sectional. Laboratory. Nineteen NCAA Division III swimmers (7 male, 12 female) (age = 18.8 ± 0.9 years, height = 174.7 ± 8.9 cm, mass = 71.6 ± 11.9 kg) volunteered to participate. Subjects had no recent history of upper extremity pathology or any previous surgery. We measured latissimus dorsi stiffness of the dominant arm while in a lengthened position with a myotonometer. We used an electromagnetic tracking device with specialized software to measure scapular kinematics at humeral elevation angles of 30°, 60°, 90°, and 110° within the scapular plane. Latissimus dorsi stiffness and scapular upward/downward rotation, internal/external rotation, and anterior/posterior tilt. Latissimus dorsi stiffness showed moderate-to-good relationships with increased scapular upward rotation (r > -0.63, P < 0.002) and posterior tilt (r > -0.62, P < 0.004) at all four angles of humeral elevation. Increased latissimus dorsi stiffness also showed moderate-to-good relationships with decreased scapular internal rotation at humeral elevation angles of 60° (r = 0.47, P = 0.03) and 90° (r = 0.54, P = 0.01). Our results suggest there are several moderate-to-good relationships between increased latissimus dorsi stiffness in swimmers and altered scapular upward rotation, internal rotation, and posterior tilt at various angles of humeral elevation. If latissimus dorsi stiffness is not addressed subsequent scapular alterations, which have been associated with shoulder dysfunction, may occur. Published by Elsevier Ltd.

Active heat exchange system development for latent heat thermal energy storage

NASA Technical Reports Server (NTRS)

Alario, J.; Haslett, R.

1980-01-01

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application. Two concepts selected for hardware development are a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which has been nickel plated to decrease adhesion forces. Suitable phase change material (PCM) storage media with melting points in the temperature range of interest (250 C to 400 C) were investigated. The specific salt recommended for laboratory tests was a chloride eutectic (20.5KCl-24/5 NaCl-55.0MgCl 2% by wt.), with a nominal melting point of 385 C.

Medial compressible forefoot sole elements reduce ankle inversion in lateral SSC jumps.

PubMed

Fleischmann, Jana; Mornieux, Guillaume; Gehring, Dominic; Gollhofer, Albert

2013-06-01

Sideward movements are associated with high incidences of lateral ankle sprains. Special shoe constructions might be able to reduce these injuries during lateral movements. The purpose of this study was to investigate whether medial compressible forefoot sole elements can reduce ankle inversion in a reactive lateral movement, and to evaluate those elements' influence on neuromuscular and mechanical adjustments in lower extremities. Foot placement and frontal plane ankle joint kinematics and kinetics were analyzed by 3-dimensional motion analysis. Electromyographic data of triceps surae, peroneus longus, and tibialis anterior were collected. This modified shoe reduced ankle inversion in comparison with a shoe with a standard sole construction. No differences in ankle inversion moments were found. With the modified shoe, foot placement occurred more internally rotated, and muscle activity of the lateral shank muscles was reduced. Hence, lateral ankle joint stability during reactive sideward movements can be improved by these compressible elements, and therefore lower lateral shank muscle activity is required. As those elements limit inversion, the strategy to control inversion angles via a high external foot rotation does not need to be used.

Discrete and continuous joint coupling relationships in uninjured recreational runners.

PubMed

Dierks, Tracy A; Davis, Irene

2007-06-01

Abnormal joint coupling is thought to be related to overuse injuries in runners. However, researchers do not yet know what constitutes normal joint coupling during running, which makes abnormal coupling difficult to define. Lower extremity kinematics were collected from 40 recreational runners during stance. Joint coupling methods were applied and, for each method, means and both within- and between-subject variability were calculated. The 95% confidence interval was used to compare differences across coupling relationships and periods of stance. Timing between rearfoot eversion, tibial internal rotation, and knee flexion were relatively synchronous while relationships involving knee internal rotation were more asynchronous. The excursion ratios showed that every 2 degrees of rearfoot eversion was coupled with 1 degrees of both tibial internal rotation and knee internal rotation. Vector coding results showed that just beyond maximum loading, all joint coupling relationships resulted in relatively equal amounts of motion, while the within-subject variability was similar throughout stance. The continuous relative phase results showed that the most out-of-phase coupling occurred in the periods around heel-strike and toe-off while the most in-phase coupling occurred in the period just beyond maximum loading of the leg. The continuous relative phase within-subject variability was greatest at the periods around heel-strike and toe-off and smallest just beyond maximum loading. With a better understanding of joint coupling in uninjured runners, these data will help to serve as a reference for future studies investigating the relationship between running injuries and abnormal joint coupling.

Physics of rotation: problems and challenges

NASA Astrophysics Data System (ADS)

Maeder, Andre; Meynet, Georges

2015-01-01

We examine some debated points in current discussions about rotating stars: the shape, the gravity darkening, the critical velocities, the mass loss rates, the hydrodynamical instabilities, the internal mixing and N-enrichments. The study of rotational mixing requires high quality data and careful analysis. From recent studies where such conditions are fulfilled, rotational mixing is well confirmed. Magnetic coupling with stellar winds may produce an apparent contradiction, i.e. stars with a low rotation and a high N-enrichment. We point out that it rather confirms the large role of shears in differentially rotating stars for the transport processes. New models of interacting binaries also show how shears and mixing may be enhanced in close binaries which are either spun up or down by tidal interactions.

International Space Station Node 1 is moved for leak test

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first element for the International Space Station, and attached Pressurized Mating Adapter-1 continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node is seen here being moved into the Shuttle payload transportation canister, where the doors will be closed for a two-week leak check. The node was moved to the canister from the element rotation stand, or test stand, where it underwent an interim weight and center of gravity determination. The final determination is planned to be performed prior to transporting Node 1 to the launch pad. Node 1 is scheduled to fly on STS-88.

International Space Station Node 1 is moved for leak test

NASA Technical Reports Server (NTRS)

1998-01-01

Node 1, the first U.S. element for the International Space Station, and attached Pressurized Mating Adapter-1 continue with prelaunch preparation activities at KSC's Space Station Processing Facility. Node 1 is a connecting passageway to the living and working areas of the space station. The node and PMA-1 are being removed from the element rotation stand, or test stand, where they underwent an interim weight and center of gravity determination. (The final determination is planned to be performed prior to transporting Node 1 to the launch pad.) Now the node is being moved to the Shuttle payload transportation canister, where the doors will be closed for a two-week leak check. Node 1 is scheduled to fly on STS-88.

Active thermal control systems for lunar and Martian exploration

NASA Technical Reports Server (NTRS)

Ewert, Michael K.; Petete, Patricia A.; Dzenitis, John

1990-01-01

Several ATCS options including heat pumps, radiator shading devices, and single-phase flow loops were considered. The ATCS chosen for both lunar and Martian habitats consists of a heat pump integral with a nontoxic fluid acquisition and transport loop, and vertically oriented modular reflux-boiler radiators. The heat pump operates only during the lunar day. The lunar and Martian transfer vehicles have an internal single-phase water-acquisition loop and an external two-phase ammonia rejection system with rotating inflatable radiators. The lunar and Martian excursion vehicles incorporate internal single-phase water acquisition, which is connected via heat exchangers to external body-mounted single-phase radiators. A water evaporation system is used for the transfer vehicles during periods of high heating.

Scapular Resting Position and Gleno-Humeral Movement Dysfunction in Asymptomatic Racquet Players: A Case-Control Study

PubMed Central

Shimpi, Apurv P.; Bhakti, Shah; Roshni, Karnik; Rairikar, Savita A.; Shyam, Ashok; Sancheti, Parag K.

2015-01-01

Background: Racquet sports, especially lawn tennis and badminton have been gaining popularity in Asian countries like India. With this increase in popularity, the injury rate in the sport has also increased. Objectives: The study will help detect the presence of gleno-humeral movement dysfunction and scapular resting position abnormality in asymptomatic racquet players, thus providing basis for screening the players and allow the clinician to determine if the asymmetry is a normal adaptation in the player or an abnormal change associated with injury. Materials and Methods: 46 asymptomatic professional players were divided into a study group of 23 players (16 tennis and 7 badminton) and control group of 23 football players. Assessment of passive gleno-humeral range of motion and distance of spine and inferior angle of scapula from corresponding spinous process were measured bilaterally and between groups. Results: There was statistically significant reduction in range of internal rotation (62.17 ± 8.09), extension (39.78 ± 4.12) and an increase in the external rotation (106.95 ± 7.49) of dominant compared to non-dominant arm of racquet players and a statistically significant decrease in internal rotation (78.69 ± 10.24), extension (44.78 ± 3.19), adduction (37.39 ± 6.54) and an increase in external rotation (102.6 ± 5.19) of dominant arm of racquet players compared to football players. Study also showed statistically significant increase in the spino-scapular distance at the level of inferior angle of scapula (10.23 ± 1.43) on dominant side compared to non-dominant. Conclusions: The dominant side scapula of asymptomatic racquet players showed increased external rotation and elevation as compared to the non-dominant side. Also, reduced shoulder internal rotation, extension and adduction and gain in shoulder external rotation was observed on the dominant side of racquet players when compared to the control group. PMID:26715968

Scapular Resting Position and Gleno-Humeral Movement Dysfunction in Asymptomatic Racquet Players: A Case-Control Study.

PubMed

Shimpi, Apurv P; Bhakti, Shah; Roshni, Karnik; Rairikar, Savita A; Shyam, Ashok; Sancheti, Parag K

2015-12-01

Racquet sports, especially lawn tennis and badminton have been gaining popularity in Asian countries like India. With this increase in popularity, the injury rate in the sport has also increased. The study will help detect the presence of gleno-humeral movement dysfunction and scapular resting position abnormality in asymptomatic racquet players, thus providing basis for screening the players and allow the clinician to determine if the asymmetry is a normal adaptation in the player or an abnormal change associated with injury. 46 asymptomatic professional players were divided into a study group of 23 players (16 tennis and 7 badminton) and control group of 23 football players. Assessment of passive gleno-humeral range of motion and distance of spine and inferior angle of scapula from corresponding spinous process were measured bilaterally and between groups. There was statistically significant reduction in range of internal rotation (62.17 ± 8.09), extension (39.78 ± 4.12) and an increase in the external rotation (106.95 ± 7.49) of dominant compared to non-dominant arm of racquet players and a statistically significant decrease in internal rotation (78.69 ± 10.24), extension (44.78 ± 3.19), adduction (37.39 ± 6.54) and an increase in external rotation (102.6 ± 5.19) of dominant arm of racquet players compared to football players. Study also showed statistically significant increase in the spino-scapular distance at the level of inferior angle of scapula (10.23 ± 1.43) on dominant side compared to non-dominant. The dominant side scapula of asymptomatic racquet players showed increased external rotation and elevation as compared to the non-dominant side. Also, reduced shoulder internal rotation, extension and adduction and gain in shoulder external rotation was observed on the dominant side of racquet players when compared to the control group.

Risk factors for overuse shoulder injuries in a mixed-sex cohort of 329 elite handball players: previous findings could not be confirmed.

PubMed

Andersson, Stig Haugsboe; Bahr, Roald; Clarsen, Benjamin; Myklebust, Grethe

2017-08-07

Shoulder injuries are common among handball players and predominantly characterised by overuse characteristics. Reduced total glenohumeral rotation, external rotation weakness and scapular dyskinesis have been identified as risk factors among elite male handball players. To assess whether previously identified risk factors are associated with overuse shoulder injuries in a large cohort of elite male and female handball players. 329 players (168 male, 161 female) from the two upper divisions in Norway were included and tested prior to the 2014-2015 season. Measures included glenohumeral internal and external rotation range of motion, isometric internal and external rotation strength, and assessment of scapular dyskinesis. Players were followed prospectively for one competitive season, with prevalence and severity of shoulder problems registered monthly using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A severity score based on players' questionnaire responses was used as the outcome measure in multivariable logistic regression to investigate associations between candidate risk factors and overuse shoulder injury. No significant associations were found between total rotation (OR 1.05 per 5° change, 95% CI 0.98 to 1.13), external rotation strength (OR 1.05 per 10 N change, 95% CI 0.92 to 1.20) or obvious scapular dyskinesis (OR 1.23, 95% CI 0.25 to 5.99) and overuse shoulder injury. A significant positive association was found between greater internal rotation (OR 1.16 per 5° change, 95% CI 1.00 to 1.34) and overuse shoulder injury. None of the previously identified risk factors were associated with overuse shoulder injuries in a mixed-sex cohort of elite handball players. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Arthroscopic suture bridge rotator cuff repair: functional outcome, repair integrity, and preoperative factors related to postoperative outcome.

PubMed

Rimmke, Nathan; Maerz, Tristan; Cooper, Ross; Yadavalli, Sailaja; Anderson, Kyle

2016-01-01

To assess the retear rate, retear size and location, the clinical impact of a retear, and preoperative patient factors related to postoperative outcome after arthroscopic suture bridge rotator cuff repair. Fifty six patients with an isolated, full-thickness supraspinatus tendon tear who underwent arthroscopic suture bridge rotator cuff repair were retrospectively identified. Patients were evaluated and rotator cuff integrity was assessed using ultrasonography. Visual analog score (VAS), the American Shoulder and Elbow Surgeon (ASES) score, shoulder range of motion and strength were used for clinical evaluation. Retears were assessed for size and location on ultrasonography. Forty two patients (75%) aged a mean 59.7 ± 8.6 years (range 41-79 years) were available for follow-up at a mean 13.5 months. Postoperative evaluation indicated significant improvements in ASES score (49.76 ± 18.2 to 86.57 ± 13.4, P < 0.001), VAS pain score (4.69 ± 2.17 to 0.63 ± 1.29, P < 0.001), forward elevation range of motion (144.1° ± 29.9 to 159.69° ± 13.9, P = 0.002), and internal rotation ROM (44.13° ± 12.0 to 52.09° ± 12.0, P = 0.003). The retear rate was 14.28% (6/42). Patients with retears were not older (P = 0.526) but had a larger preoperative tear size (3.25 cm ± 0.5 vs. 2.05 cm ± 0.48, P < 0.001). Preoperative tear size was significantly associated with a postoperative retear (P < 0.001). The duration of preoperative symptoms was significantly associated with pain (P = 0.029), pain improvement (P = 0.013), internal rotation ROM (P = 0.002), and internal rotation strength (P = 0.004). Arthroscopic suture bridge repair provides good clinical results with a low retear rate. The duration of preoperative symptoms was associated with postoperative outcome, indicating that delaying surgery may result in inferior outcomes. IV, Case Series.

Toward Realistic Dynamics of Rotating Orbital Debris, and Implications for Lightcurve Interpretation

NASA Technical Reports Server (NTRS)

Ojakangas, Gregory W.; Cowardin, H.; Hill, N.

2011-01-01

Optical observations of rotating space debris near GEO contain important information on size, shape, composition, and rotational states, but these aspects are difficult to extract due to data limitations and the high number of degrees of freedom in the modeling process. For tri-axial rigid debris objects created by satellite fragmentations, the most likely initial rotation state has a large component of initial angular velocity directed along the intermediate axis of inertia, leading to large angular reorientations of the body on the timescale of the rotation period. This lends some support to the simplest possible interpretation of light curves -- that they represent sets of random orientations of the objects of study. However, effects of internal friction and solar radiation are likely to cause significant modification of rotation states within a time as short as a few orbital periods. In order to examine the rotational dynamics of debris objects under the influences of these effects, a set of seven first-order coupled equations of motion were assembled in state form: three are Euler equations describing the rates of change of the components of angular velocity in the body frame, and four describe the rates of change of the components of the unit quaternion. Quaternions are a four-dimensional extension of complex numbers that form a seamless, singularity-free representation of body orientation on S3. The Euler equations contain explicit terms describing torque from solar radiation in terms of spherical harmonics, and terms representing effects of a prescribed rate of internal friction. Numerical integrations of these equations of motion are being performed, and results will be presented. Initial tests show that internal friction without solar radiation torque leads to rotation about the maximum principal axis of inertia, as required, and solar radiation torque is expected to lead to spin-up of objects. Because the axis of maximum rotational inertia tends to be roughly coincident with the normal to the largest projected cross-sectional area, internal friction is expected to lead to reduced variation of light curve amplitudes at a given phase angle, but a large dependence of the same on phase angle. At a given phase angle, databases are generated which contain reflected intensities for comprehensive sets of equally-likely orientations, represented as unit quaternions. When projected onto three dimensions (S2) and color-coded by intensity, the set is depicted as points within a solid, semi-transparent unit sphere, within which all possible reflected intensities for an object at a given phase angle may be inspected simultaneously. Rotational sequences are represented by trajectories through the sphere. Databases are generated for each of a set of phase angles separately, forming a comprehensive dataset of reflected intensities spanning all object orientations and solar phase angles. Symmetries in the problem suggest that preferred rotation states are likely, defined relative to the object-sun direction in inertial space and relative to the maximum principal axis of inertia in the body coordinate system. Such rotation states may greatly simplify the problem of light curve interpretation by reducing the number of degrees of freedom in the problem.

Association between rotation-related impairments and activity type in people with and without low back pain

PubMed Central

Weyrauch, Stephanie A.; Bohall, Sara C.; Sorensen, Christopher J.; Van Dillen, Linda R.

2015-01-01

Objective To determine if people with low back pain (LBP) who regularly participated in a rotation-related activity displayed more rotation-related impairments than people without LBP who did and did not participate in the activity. Design Secondary analysis of data from a case-control study. Setting Musculoskeletal analysis laboratory at an academic medical center. Participants A convenience sample of 55 participants with LBP who participated in a rotation-related sport, 26 back healthy controls who participated in a rotation-related sport (BHC+RRS) and 42 back healthy controls who did not participate in a rotation-related sport (BHC-RRS). Participants were matched based on age, gender, and activity level. Interventions Not applicable. Main Outcome Measures The total number of rotation-related impairments and asymmetric rotation-related impairments identified during a standardized clinical examination. Results Compared to the BHC-RRS group, both the LBP and BHC+RRS groups displayed significantly more (1) rotation-related impairments (LBP: p<.001; BHC+RRS: p=.015) (2) asymmetric rotation-related impairments (LBP: p=.006; BHC+RRS: p=.020) and (3) rotation-related impairments with trunk movement tests (LBP: p=.002; BHC+RRS: p<.001). The LBP group had significantly more rotation-related impairments with extremity movement tests than both of the back healthy groups (BHC+RRS: p=.011; BHC-RRS: p<.001). Conclusions LBP and BHC+RRS groups demonstrated a similar number of total rotation-related impairments and asymmetric rotation-related impairments, and these numbers were greater than those of the BHC-RRS group. Compared to people without LBP, people with LBP displayed more rotation-related impairments when moving an extremity. These findings suggest that impairments associated with extremity movements may be associated with having a LBP condition. PMID:25933914

Vibration sensing in smart machine rotors using internal MEMS accelerometers

NASA Astrophysics Data System (ADS)

Jiménez, Samuel; Cole, Matthew O. T.; Keogh, Patrick S.

2016-09-01

This paper presents a novel topology for enhanced vibration sensing in which wireless MEMS accelerometers embedded within a hollow rotor measure vibration in a synchronously rotating frame of reference. Theoretical relations between rotor-embedded accelerometer signals and the vibration of the rotor in an inertial reference frame are derived. It is thereby shown that functionality as a virtual stator-mounted displacement transducer can be achieved through appropriate signal processing. Experimental tests on a prototype rotor confirm that both magnitude and phase information of synchronous vibration can be measured directly without additional stator-mounted key-phasor sensors. Displacement amplitudes calculated from accelerometer signals will become erroneous at low rotational speeds due to accelerometer zero-g offsets, hence a corrective procedure is introduced. Impact tests are also undertaken to examine the ability of the internal accelerometers to measure transient vibration. A further capability is demonstrated, whereby the accelerometer signals are used to measure rotational speed of the rotor by analysing the signal component due to gravity. The study highlights the extended functionality afforded by internal accelerometers and demonstrates the feasibility of internal sensor topologies, which can provide improved observability of rotor vibration at externally inaccessible rotor locations.

Internal waves and rectification in a linearly stratified fluid

NASA Astrophysics Data System (ADS)

Pérenne, Nicolas; Renouard, Dominique P.

Laboratory experiments were performed in a 13-m diameter rotating tank equipped with a continuous shelf break geometry and a central piston-like plunger. The fluid density was linearly stratified. The amplitude and period of the plunger, the rotation rate of the platform and the stratification are the parameters of the problem. The density fluctuations at six stations above and at mid-depth of the slope, along with dye visualization of the flow, were recorded. A limited set of experiments showed that a barotropic periodical forcing generated a first mode baroclinic wave which initially appears at the slope and propagates offshore. The likely presence of internal energy rays either slightly above, or immediately along the slope, is in agreement with previous analytical, laboratory and selected oceanic observations. In the former case, the stratification was such that the slope flow at mid-depth was supercritical while in the latter case, slope flow at mid-depth was critical. Rotation tended to decrease the amplitude of the generated internal wave. Also, non-linear processes were likely to act upon these waves for their normalized amplitude tended to decrease as the forcing increased (for similar forcing period, rotation rate and stratification). After the internal wave reflected from the plunger reaches the slope, there is a complex non-stationary regime with an occurrence of internal wave breaking in the vicinity of the slope. Thus there was an appearance of localized patches of turbulence and mixing. These events appeared both in dye visualization and in density fluctuations records. The subsequent mixing, or else the combined effect of topographical rectification and mixing, led to the appearance of a distinct Lagrangian transport, localized in the first few centimeters above the slope and oriented so as to leave the shallow waters on the right of its displacement.

Anatomical versus non-anatomical single bundle anterior cruciate ligament reconstruction: a cadaveric study of comparison of knee stability.

PubMed

Lim, Hong-Chul; Yoon, Yong-Cheol; Wang, Joon-Ho; Bae, Ji-Hoon

2012-12-01

The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction. Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction. Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30° of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p < 0.05). In contrast, central anatomical single bundle ACL reconstruction showed no significant difference of ATT compared to those in ACL intact group (p > 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees. Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction.

Modeling the Internal Kinematics (Rotation and Dispersion) of Distant Galaxies (z ~ 1.0) Using Multi-PA Keck DEIMOS Slit Spectra

NASA Astrophysics Data System (ADS)

Miao, Connie; Chen, Jerry; Torres Hernandez, Jose; Guhathakurta, Puragra; Jang, Hyerin

2017-01-01

The stark difference between the chaotic internal motion of distant galaxies and the ordered rotation of typical local spiral galaxies suggests that disordered galaxies at high redshifts (i.e., early times in the Universe's history) gradually settle into well ordered disk morphologies with ordered rotation. We have used slit spectra obtained with Keck DEIMOS at four different position angles for 133 distant objects (z ~ 1.0) in the GOODS-N field. The emission lines in the 2D spectra of the galaxies were used to calculate the redshift/velocity at each spatial location. For each slit row, the distribution of flux over velocity was modeled as a Gaussian curve from which we obtained the radial velocity and spread of radial velocity. Rotation curves and velocity dispersions for each galaxy at each slit angle were plotted at these values. We qualitatively classified galaxies as regularly rotating, merging, face-on, or unable to be determined by examining overlays of the rotation curves from the four slit angles. We found that regular rotating galaxies tended to have peak velocity dispersion at the center while mergers had fairly constant velocity dispersions. Face-on galaxies had chaotic and inconsistent velocity dispersions between different slit angles. Regularly rotation galaxies represented 45% of our sample and mergers represented 27%. The relative percentage of galaxies that were either regularly rotating or mergers roughly matched those of the literature. This research was supported by NASA and the National Science Foundation. Most of this work was carried out by high school students working under the auspices of the Science Internship Program at UC Santa Cruz.

The impact of a dedicated research education month for anesthesiology residents.

PubMed

Freundlich, Robert E; Newman, Jessica W; Tremper, Kevin K; Mhyre, Jill M; Kheterpal, Sachin; Sanford, Theodore J; Tait, Alan R

2015-01-01

An educational intervention was implemented at the University of Michigan starting in 2008, in which anesthesiology interns complete a dedicated month-long didactic rotation in evidence-based medicine (EBM) and research methodology. We sought to assess its utility. Scores on a validated EBM test before and after the rotation were compared and assessed for significance of improvement. A survey was also given to gauge satisfaction with the quality of the rotation and self-reported improvement in understanding of EBM topics. Fourteen consecutive interns completed the research rotation during the study period. One hundred percent completed both the pre- and postrotation test. The mean pretest score was 7.78 ± 2.46 (median = 7.5, 0-15 scale, and interquartile range 7.0-10.0) and the mean posttest score was 10.00 ± 2.35 (median = 9.5, interquartile range 8.0-12.3), which represented a statistically significant increase (P = 0.011, Wilcoxon signed-rank test). All fourteen of the residents "agreed" or "strongly agreed" that they would recommend the course to future interns and that the course increased their ability to critically review the literature. Our findings demonstrate that this can be an effective means of improving understanding of EBM topics and anesthesiology research.

Three-dimensional innate mobility of the human foot bones under axial loading using biplane X-ray fluoroscopy

PubMed Central

Hosoda, Koh; Shimizu, Masahiro; Ikemoto, Shuhei; Nagura, Takeo; Seki, Hiroyuki; Kitashiro, Masateru; Imanishi, Nobuaki; Aiso, Sadakazu; Jinzaki, Masahiro; Ogihara, Naomichi

2017-01-01

The anatomical design of the human foot is considered to facilitate generation of bipedal walking. However, how the morphology and structure of the human foot actually contribute to generation of bipedal walking remains unclear. In the present study, we investigated the three-dimensional kinematics of the foot bones under a weight-bearing condition using cadaver specimens, to characterize the innate mobility of the human foot inherently prescribed in its morphology and structure. Five cadaver feet were axially loaded up to 588 N (60 kgf), and radiographic images were captured using a biplane X-ray fluoroscopy system. The present study demonstrated that the talus is medioinferiorly translated and internally rotated as the calcaneus is everted owing to axial loading, causing internal rotation of the tibia and flattening of the medial longitudinal arch in the foot. Furthermore, as the talus is internally rotated, the talar head moves medially with respect to the navicular, inducing external rotation of the navicular and metatarsals. Under axial loading, the cuboid is everted simultaneously with the calcaneus owing to the osseous locking mechanism in the calcaneocuboid joint. Such detailed descriptions about the innate mobility of the human foot will contribute to clarifying functional adaptation and pathogenic mechanisms of the human foot. PMID:29134100

Effects of five hindfoot arthrodeses on foot and ankle motion: Measurements in cadaver specimens

PubMed Central

Zhang, Kun; Chen, Yanxi; Qiang, Minfei; Hao, Yini

2016-01-01

Single, double, and triple hindfoot arthrodeses are used to correct hindfoot deformities and relieve chronic pain. However, joint fusion may lead to dysfunction in adjacent articular surfaces. We compared range of motion in adjacent joints before and after arthrodesis to determine the effects of each procedure on joint motion. The theory of moment of couple, bending moment and balanced loading was applied to each of 16 fresh cadaver feet to induce dorsiflexion, plantarflexion, internal rotation, external rotation, inversion, and eversion. Range of motion was measured with a 3-axis coordinate measuring machine in a control foot and in feet after subtalar, talonavicular, calcaneocuboid, double, or triple arthrodesis. All arthrodeses restricted mainly internal-external rotation and inversion-eversion. The restriction in a double arthrodesis was more than that in a single arthrodesis, but that in a calcaneocuboid arthrodesis was relatively low. After triple arthrodeses, the restriction on dorsiflexion and plantarflexion movements was substantial, and internal-external rotation and inversion-eversion were almost lost. Considering that different arthrodesis procedures cause complex, three-dimensional hindfoot motion reductions, we recommend talonavicular or calcaneocuboid arthrodesis for patients with well-preserved functions of plantarflexion/dorsiflexion before operation, subtalar or calcaneocuboid arthrodesis for patients with well-preserved abduction/adduction, and talonavicular arthrodesis for patients with well-preserved eversion/inversion. PMID:27752084

Cross-cultural challenges for assessing medical professionalism among clerkship physicians in a Middle Eastern country (Bahrain): feasibility and psychometric properties of multisource feedback

PubMed Central

Al Ansari, Ahmed; Al Khalifa, Khalid; Al Azzawi, Mohamed; Al Amer, Rashed; Al Sharqi, Dana; Al-Mansoor, Anwar; Munshi, Fadi M

2015-01-01

Background We aimed to design, implement, and evaluate the feasibility and reliability of a multisource feedback (MSF) system to assess interns in their clerkship year in the Middle Eastern culture, the Kingdom of Bahrain. Method The study was undertaken in the Bahrain Defense Force Hospital, a military teaching hospital in the Kingdom of Bahrain. A total of 21 interns (who represent the total population of the interns for the given year) were assessed in this study. All of the interns were rotating through our hospital during their year-long clerkship rotation. The study sample consisted of nine males and 12 females. Each participating intern was evaluated by three groups of raters, eight medical intern colleagues, eight senior medical colleagues, and eight coworkers from different departments. Results A total of 21 interns (nine males and 12 females) were assessed in this study. The total mean response rates were 62.3%. A factor analysis was conducted that found that the data on the questionnaire grouped into three factors that counted for 76.4% of the total variance. These three factors were labeled as professionalism, collaboration, and communication. Reliability analysis indicated that the full instrument scale had high internal consistency (Cronbach’s α 0.98). The generalizability coefficients for the surveys were estimated to be 0.78. Conclusion Based on our results and analysis, we conclude that the MSF tool we used on the interns rotating in their clerkship year within our Middle Eastern culture provides an effective method of evaluation because it offers a reliable, valid, and feasible process. PMID:26316836

Probable Rotation States of Rocket Bodies in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Ojakangas, Gregory W.; Anz-Meador, P.; Cowardin, H.

2012-01-01

In order for Active Debris Removal to be accomplished, it is critically important to understand the probable rotation states of orbiting, spent rocket bodies. As compared to the question of characterizing small unresolved debris, in this problem there are several advantages: (1) objects are of known size, mass, shape and color, (2) they have typically been in orbit for a known period of time, (3) they are large enough that resolved images may be obtainable for verification of predicted orientation, and (4) the dynamical problem is simplified to first order by largely cylindrical symmetry. It is also nearly certain for realistic rocket bodies that internal friction is appreciable in the case where residual liquid or, to a lesser degree, unconsolidated solid fuels exist. Equations of motion have been developed for this problem in which internal friction as well as torques due to solar radiation, magnetic induction, and gravitational gradient are included. In the case of pure cylindrical symmetry, the results are compared to analytical predictions patterned after the standard approach for analysis of symmetrical tops. This is possible because solar radiation and gravitational torques may be treated as conservative. Agreement between results of both methods ensures their mutual validity. For monotone symmetric cylinders, solar radiation torque vanishes if the center of mass resides at the geometric center of the object. Results indicate that in the absence of solar radiation effects, rotation states tend toward an equilibrium configuration in which rotation is about the axis of maximum inertia, with the axis of minimum inertia directed toward the center of the earth. Solar radiation torque introduces a modification to this orientation. The equilibrium state is asymptotically approached within a characteristic timescale given by a simple ratio of relevant characterizing parameters for the body in question. Light curves are simulated for the expected asymptotic final rotation states of model objects, and these are compared to data derived from physical models of the same objects, tested in the Optical Measurements Center at JSC. Comparison to relevant light curves from actual orbiting rocket bodies are also performed, and diagnostic features of such curves are examined.