1,047 research outputs found
CORRELATIONS BETWEEN EXPERTSâ SCORING AND BIOMECHANICAL ASSESSMENT IN BALLET MOVEMENT
The purpose of this study was to investigate the relationship between assessment of ballet movement by experts and biomechanical variables. Releve point movement was recorded by a video camcorder (Sony, Japan) for the expert assessment. Eight infrared cameras (Qualisys, Sweden) and two force plates (Kistler, Switzerland) were used for biomechanical analysis. A High reliability in score for flexibility and assistance among three judges was found. Based on the analysis of correlations, flexibility and ROM were positively correlated as the subject who performed wider motion at the ankle achieved higher sores in flexibility from the judges. Negative correlations were found between the judgesâ scores in assistance and ankle joint power as well as their scores in balance and COP on the left side. Development of objective and reliable scoring standards in ballet based on the understanding of body movements supported by the verification of scientific method is needed
The feasibility of shear wave elastography for diagnosing superficial benign soft tissue masses
Purpose The purpose of this study was to investigate the feasibility of shear wave ultrasound elastography for differentiating superficial benign soft tissue masses through a comparison of their shear moduli. Methods We retrospectively analyzed 48 masses from 46 patients from February 2014 to May 2016. Surgical excision, fine-needle aspiration, and clinical findings were used for the differential diagnosis. The ultrasonographic examinations were conducted by a single musculoskeletal radiologist, and the ultrasonographic findings were reviewed by two other radiologists who were blinded to the final diagnosis. Conventional ultrasonographic features and the median shear modulus were evaluated. We compared the median shear moduli of epidermoid cysts, ganglion cysts, and lipomatous tumors using the Kruskal-Wallis test. Additionally, the Mann-Whitney U test was used to compare two distinct groups. Results Significant differences were found in the median shear moduli of epidermoid cysts, ganglion cysts, and lipomatous tumors (23.7, 5.8, and 9.2 kPa, respectively; P=0.019). Epidermoid cysts showed a greater median shear modulus than ganglion cysts (P=0.014) and lipomatous tumors (P=0.049). Conclusion Shear wave elastography may contribute to the differential diagnosis of superficial benign soft tissue masses through a direct quantitative analysis
Microlensing under Shear
We investigate the distortions due to this shear in the microlensing light
curves and in the astrometric microlensing centroid shift trajectories. As
expected, the light curve deviation increases as the shear increases and the
impact parameter decreases. Although the light curve in the presence of a small
shear is similar to the simple Paczynski curve with a slightly smaller impact
parameter, the detailed difference between the light curve with and without
shear reflects the direction and the magnitude of the shear. The centroid shift
trajectory also deviates from a simple ellipse in the presence of shear. The
distortion of the centroid shift trajectory increases as the impact parameter
decreases, and the shape of the trajectory becomes complicated when the impact
parameter becomes small enough. The magnitude of the maximum distortion depends
on the magnitude and the direction of the shear. For a source trajectory in a
given direction, the time of the maximum distortion depends mostly on the
impact parameter and hardly on the shear. It is possible to determine the
magnitude of the shear and its direction if both the time and the magnitude of
the maximum astrometric distortion are measured. The magnitude of the shear
produced by the Galactic bulge or a globular cluster falls in the range
10^{-6}--10^{-4} in normalized units. Although the actual determination of the
shear from the Galactic sub-structures will not be easy due to complications
such as binary companion, future large scale microlensing experiments may
enable us to determine the shear in some high amplification events, leading
eventually to mapping the Galactic mass distribution.Comment: 15 pages, 11 figures, ApJ accepe
ALTERATIONS IN JOINT KINEMATICS AND KINETICS DURING DOWNHILL RUNNING
The purpose of this investigation was to find how joint kinematics and kinetics during downhill running change compared to level running. Fifteen recreational runners ran on a force plate imbedded treadmill with three different slopes (0 Âș, -6Âș, and -9Âș) at a controlled speed of 3.2 m/s. Ten steps on each slope were selected for analysis. Increased knee flexion with decreased ankle plantar-flexion and hip flexion was found during downhill running compared to level running. Decreased peak propulsive ground reaction force and posterior impulse were found during downhill running compared to level running. Additionally, increased extension moment with increased negative joint power at the knee and decreased plantar-flexion moment with decreased negative joint power at the ankle were found during downhill running compared to level running
GAIT ASYMMETRY IN CHILDREN WITH DOWN SYNDROME
It has been reported that approximately 80% of children with Down syndrome (OS) exhibit gait problems (Matteo, 2002), characterized by flat-footed contact with no heel-strike, excessive abduction of the leg in the swing phase, and abnormal knee and hip f1exions throughout the gait cycle (Parker et aI., 1986). Due to muscle hypotonia, muscle weakness, !igamentous laXity, and other orthopedic abnormalities, different gait characteristics exist. The purpose of this study was to investigate the gait (walking and running) asymmetry in children with OS
Hybrid Procedure for a Traumatic Aortic Rupture Consisting of Endovascular Repair and Minimally Invasive Arch Vessel Transposition without Sternotomy
Emergency surgical repair for acute traumatic aortic ruptures has been associated with a high peri-procedural mortality rate. Endovascular stent-grafting, as a less invasive procedure, has shown encouraging results. This report describes a patient with a short landing zone, who was treated by transposing the supra-aortic branch without sternotomy, followed by covered stent-grafting with an extended proximal bare portion to enhance fixation
Limits of Binaries That Can Be Characterized by Gravitational Microlensing
Due to the high efficiency of planet detections, current microlensing planet
searches focus on high-magnification events. High-magnification events are
sensitive to remote binary companions as well and thus a sample of
wide-separation binaries are expected to be collected as a byproduct. In this
paper, we show that characterizing binaries for a portion of this sample will
be difficult due to the degeneracy of the binary-lensing parameters. This
degeneracy arises because the perturbation induced by the binary companion is
well approximated by the Chang-Refsdal lensing for binaries with separations
greater than a certain limit. For binaries composed of equal mass lenses, we
find that the lens binarity can be noticed up to the separations of
times of the Einstein radius corresponding to the mass of each lens. Among
these binaries, however, we find that the lensing parameters can be determined
only for a portion of binaries with separations less than times of
the Einstein radius.Comment: 5 pages, 3 figures, 1 tabl
SPRINTING SPEED OF ELITE SPRINTERS AT THE WORLD CHAMPIONSHIPS
The purpose of this study was to analyze the sprinting speed of the sprinters during the men's 100 m events at the IAAF World Championships (WC) in order to provide important information to track and field coaches and athletes. Sprinting speed of the sprinters was collected by using laser guns (Laveg Sport, Jenoptik, Germany) during the World Championships in Daegu 2011. Then, data from Osaka 2007 WC and Berline 2009 WC were included in the analysis. The findings indicated that a reduction of a sprinterâs maximum speed is correlated with their performance time (
Microlensing Optical Depth Revisited with Recent Star Counts
More reliable constraints on the microlensing optical depth comes from a
better understanding of the Galactic model. Based on well-constrained Galactic
bulge and disk models constructed from survey observations, such as, HST,
2MASS, and SDSS, we calculate the microlensing optical depths toward the
Galactic bulge fields, and compare them with recent results of microlensing
surveys. We test chi^2 statistics of microlensing optical depths expected from
those models, as well as previously proposed models, using two types of data:
optical depth map in (l, b) and averaged optical depth over the Galactic
longitude l as a function of the latitude b. From this analysis, we find that
the Galactic bulge models of 2MASS, Han & Gould (2003), and G2 of Stanek et al.
(1997) show a good agreement with the microlensing optical depth profiles for
all the microlensing observations, compared with E2 of Stanek et al. (1997). We
find, on the other hand, that models involving an SDSS disk model produce
relatively higher chi^2 values. It should be noted that modeled microlensing
optical depths diverge in the low Galactic latitude, |b| < 2 arcdeg. Therefore,
we suggest the microlensing observation toward much closer to central regions
of the Galaxy to further test the proposed Galactic models, if it is more
technically feasible than waiting for large data set of microlensing events.Comment: 15 pages, 3 figures and 3 tables, accepted for publication in Ap
SUCCESSFUL FACTORS OF 540° DWIHURYEOCHAGI IN TAEKWONDO
The purpose of our study was to provide fundamental information about success factors of 540° Dwihuryeochagi in Taekwondo. Twenty Taekwondo athletes who participated in the 2012 Taekwondo Kyukpa Wang (breaking king) championship: ten successful athletes (S, age: 23.1±1.6 yrs, height: 171.0±3.5 cm, body mass: 66.4±7.1 kg) and ten failed athletes (F, age: 22.3±1.8 yrs, height: 172.1±5.4 cm, body mass: 64.4±4.2 kg) were selected. Three-dimensional motion analysis using a system of 3 video cameras with a sampling of 60 fields/s was performed during the competition of 540 ° Dwihuryeochagi. Based on the findings, it is concluded that success factors of 540° Dwihuryeochagi were horizontal velocity of COM during P1, vertical velocity of COM during P2, and the time, kick distance, velocity and angle of lower extremities of P3-P4
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