1,279 research outputs found
INTEGRATIVE APPROACHES FOR SUCCESSFUL REHABILITATION
Currently it is common that sport biomechanists and orthopedic surgeons work together for sports injury prevention and rehabilitation training in Korea. Functional training is the latest issue in not sports injury prevention but rehabilitation at the moment. It works on the premise that the body is designed to work by performing patterns of movement which engages muscles in natural way rather than in one plane of movement. Understanding how each of the body's joints or systems works independently is essential to see whether that section has the capacity to function as part of the whole. A biornechanical screen will provide this information and is used as a precursor to functional screening and training. Once each joint or system has the capacity to function correctly, functional training using combinations of joints and systems, then becomes more likely and the movements are pure not compensatory. Dr. Junggi Hong is the most active scholar and practitioner in the performance training and sports medicine for athletes in Korea. He contributes athletic rehabilitation and injury prevention field in Korea through co-work with many athletic trainers in various professional sports teams and physicians in sports medical centers in Korea
THE KINEMATIC ANALYSIS OF 500M SPRINT START IN 2005 WORLD SHORT TRACK SPEED SKATING CHAMPIONSHIP
A field study was performed attempting a kinematic estimation for six female foreign skaters, who participated in the 500m female final round competition. The three dimensional motion analysis with DLT method was executed using four video cameras for analyzing the actual competition situation. The following conclusions are drawn; the elapsed time by phase in start motion of the foreign skaters appeared shorter than those of Korean skaters, so the start training of Korean skaters should be strengthened. Also the displacement of COG in the foreign skaters appeared shorter than those of Korean skaters. The velocity of COG and maximum velocity of skate blade of foreign skaters are faster than those of Korean skaters. And the foreign skaters showed the superior early velocity change
COMPARISON OF FOOT MORPHOLOGY AND PREFERRED SHOE FOR IMPROVING RUNNING SHOE FITTING
The purpose of this study was to compare the shoe internal space and foot shapes of different type for increasing sense of shoe fitting. 347 healthy subjects (male=160; female=187) without any pathological conditions of the foot participated in this study. 11 pairs of running shoes have different size (230-280mm) with same material and appearances were prepared and the shapes of shoe last were also measured for these shoes. In order evaluating the sense of shoe fitting, 6 fit indicators were analysed by comparing the shape of shoe last with foot morphology. We could find that people with wider feet tend to wear tighter shoes and narrower feet preferred to wear looser shoes that seems to significantly affect by the experience. And the sense of shoe fitting was significant different from gender and foot type which can be used as important data for recommending shoe size and to make customized shoe
THE EFFECT OF TURNING DIRECTION ON LOWER EXTREMITY JOINT MOMENTS DURING FAST CUTTING MOVEMENT
The purpose of this study was to investigate the effect of turning movement on the three-dimensional moments at the ankle, knee, and hip joints. Data were collected using video cameras and force plate. Eight male recreational basketball players were tested during fast running (4.5m/s) and when cutting to the right or left off (+60, +30, 0, -30, and -60). The inverse dynamics approach was used to integrate the body segment parameter, kinetic and force plate data, and to solve the resultant joint moments. Greater abduction moments of the ankle, adduction moments of the knee and external rotation and adduction moments of the hip were found compared to values for straight running. Greater inversion and adduction moments of the ankle, abduction moments of the knee and hip were found compared to values for straight running
A QUALITATIVE COMPARISON OF DlSC MOVEMENT AND INTER JOINT COORDINATION OF UPPER LIMB IN FLYING DlSC FOREHAND THROWING
The aim of this study was to investigate the characteristics of players according to their experience levels during Flying disc forehand throwing. Two players were recruited for this study according to their experience level (skilled (SP) and unskilled (UP)). 3 dimensional motion analysis were performed to analyse the disc trajectory and inter-joint coordination patterns qualitatively. SP showed greater range of disc trajectory both on horizontal and sagittal plane according to their release point. Coordination patterns showed differences especially on shoulder and wrist joint angles. Disc trajectories and inter joint coordination results can be explained as a result of changes on upper body moments according to the experience level of players. Therefore, these characteristics increase the initial velocity of disc which can affect the disc
THE EFFECTS OF SUSPENSION FUNCTION OF HIKING BOOTS ON THE STABILITY OF THE FOOT
The purpose of this study is to investigate the effects of suspension function of hiking boot on the stability of foot. 8 participants free from injury to the triceps surae muscle group in recent years and able to perform jumping participated in this test. 2-D kinematic analysis and kinetic analysis were conducted for the data acquisition. The maximum suspension angle of suspension boot was greater than that of normal boot for eversion condition; on the contrary the maximum loading rate of normal boot was greater than that of suspension boot for inversion condition. These results meant that the suspension function helps the boot keep stable shortly after landing through the control of rearfoot angle. Moreover, if we apply a lower threshold level at medial part of boot, suspension function will show its ability even though at medial landing. It was concluded that an improved suspension function may help to reduce fatigue and prevent injury such as ankle sprain in hiking on uneven surface
Dirac Bilayer Metasurfaces as an Inverse Gires-Tournois Etalon
Efficient transmissive pure-phase resonances are highly desirable for optical
modulation and wavefront engineering. Here, we propose a novel principle to
realize a pure-phase resonance in an extremely broad transmission band, as
opposed to previous approaches restricted to operating in reflection mode or
over a narrow spectral band. We show that a glide-symmetric bilayer metasurface
mathematically mimicking a two-dimensional Dirac semimetal induces
unidirectional guided-mode excitation and perfect leakage-radiation blazing at
the transmission channel. These effects create a peculiar resonant-scattering
configuration, similar to the classical reflective Gires-Tournois etalon, but
in transmission, providing full 2pi phase modulation with constant
transmittance near 100%. Most importantly, this effect persists over an
extremely wide band, associated with topological effects. Hence, our proposed
approach produces a spectrally and parametrically robust pure-phase resonance
effect in transmission, which is highly beneficial for practical applications.Comment: 11 pages, 5 figure
Acupuncture Muscle Channel in the Subcutaneous Layer of Rat Skin
AbstractUsing a mixed-dye injection technique, we found a novel kind of muscle fiber with a lumen, established its precise location in the subcutaneous muscle layer along the acupuncture muscle of the bladder line, and determined its detailed ultrastructure. The channels with flowing liquid were a novel kind of muscle fibers with lumens and they were located in the subcutaneous muscle layer of rat. Their detection was realized by using chrome-hematoxylin and a mixture of fluorescent nanoparticles and commercial Pelikan ink. These acupuncture muscle channels were hidden among the neighboring skin skeletal muscle fibers and were barely distinguishable from them with light microscopes. Only with a transmission electron microscope were their characteristic features shown to be different from normal skin skeletal muscle. These features included undifferentiated muscle fibers that resembled immature myofibrils without Z-lines and reassembled telophase nuclei
Coupling angle variability of upper extremity during 5 weeks overarm throwing self-practice
The role of variability is still unknown for biomechanists whether it's useful or not for the performance or skill learning. The aim of this study was to investigate coupling angle variability (CAV) at the early phase of skill acquisition of overarm throwing without any feedback about the result or performance. 7 healthy female without any throwing experience participated in this study. Each participant participated a total of 15 sessions in the laboratory (3 days in a week x 5 weeks). Coupling angle variability of angle-angle diagrams (AAD) calculated for combinations of trunk flexion (TF) –lateral flexion(TL), humeral elevation (HE)- humeral plane of elevation (HP), elbow flexion-extension(EF). There were no significant changes for CAV, however individual AADs showed different patterns for each individual. For understanding the role of the variability in skill learning or performance, individual variability analysis may give information better than the group means
Insight into highly conserved H1 subtype-specific epitopes in influenza virus hemagglutinin
Influenza viruses continuously undergo antigenic changes with gradual accumulation of mutations in hemagglutinin (HA) that is a major determinant in subtype specificity. The identification of conserved epitopes within specific HA subtypes gives an important clue for developing new vaccines and diagnostics. We produced and characterized nine monoclonal antibodies that showed significant neutralizing activities against H1 subtype influenza viruses, and determined the complex structure of HA derived from a 2009 pandemic virus A/Korea/01/2009 (KR01) and the Fab fragment from H1-specific monoclonal antibody GC0587. The overall structure of the complex was essentially identical to the previously determined KR01 HA-Fab0757 complex structure. Both Fab0587 and Fab0757 recognize readily accessible head regions of HA, revealing broadly shared and conserved antigenic determinants among H1 subtypes. The beta-strands constituted by Ser110-Glu115 and Lys169-Lys170 form H1 epitopes with distinct conformations from those of H1 and H3 HA sites. In particular, Glu112, Glu115, Lys169, and Lys171 that are highly conserved among H1 subtype HAs have close contacts with HCDR3 and LCDR3. The differences between Fab0587 and Fab0757 complexes reside mainly in HCDR3 and LCDR3, providing distinct antigenic determinants specific for 1918 pdm influenza strain. Our results demonstrate a potential key neutralizing epitope important for H1 subtype specificity in influenza virus
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