• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• 제18권2호
• /
• pp.49-55
• /
• 2012

Background: The purposes of this study were to: 1) investigate the relation between thoracic kyphosis, postural stiffness and thoracic rotation and 2) the intra-rater reliability of the measurement methods for thoracic kyphosis and rotation angle. Methods: Thirty-nine young adults (13 males, 26 females) participated in the study. Thoracic kyphosis was measured using a Flexicurve while standing in their usual relaxed posture and then in their maximally erector posture. Index of kyphosis (IK) measures taken in the relaxed and maximally erect positions were used to estimate postural stiffness. Thoracic rotation range of motion (ROM) was measured using universal goniometer and inclinometer in two positions. The association between the magnitude of the IK and thoracic stiffness and thoracic rotation ROM was also examined. Reliability was determined using intra-class correlation coefficients (ICC). Results: When measured from the mean relaxed IK (${\pm}SD$) was 7.42 (${\pm}1.47$) and mean erect IK was 4.92 (${\pm}1.63$) and mean IK ratio was 1.66 (${\pm}.65$). The relaxed IK was significantly correlated with the range of motion thoracic rotation in two positions (r=.503~580, p<.01). Conclusion: Thoracic kyphosis in relaxed position was associated with the range of motion thoracic rotation. Thoracic kyphosis measurement with the Flexicurve and range of motion 2 techniques of thoracic rotation showed good reliablity and may be a useful measurement tool in clinical practice.

• Korean Journal of Applied Biomechanics
• /
• 제13권3호
• /
• pp.81-98
• /
• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1344-1348
• /
• 2003

A precision micro-positioning system with a high displacement resolution and wide motion range has been required for industrialized applications in variety fields. This paper discusses the design of a precision micro-rotation stage with flexure hinges. Proposed system is applied to grinding machine for micro parts. Rotational motion is generated with this system. For this systems having a full rotation motion with high precision, a dual servo system with a coarse stage and a fine stage is proposed.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• 제46권5호
• /
• pp.135-142
• /
• 2009

Since hold-type display systems have been developed, frame-rate up conversion (FRUC) is an essential technique to improve the temporal resolution in the display. FRUC improves the temporal resolution by interpolating one or multiple intermediate frames between two adjacent frames. In this paper, a new frame-rate up-conversion algorithm based on bilateral motion refinement with rotation is proposed. First, we perform bi-directional motion estimation between adjacent two frames to obtain a motion vector for each block. Then, we apply a modified median filtering to motion vectors for outlier-rejection and motion field smoothing. The filtered motion vectors are updated by the bilateral motion refinement with rotation. After the refined motion vector is obtained, the intermediate frame is generated by applying the overlapped block motion compensation (OBMC). Experimental results show that the proposed algorithm provides a better performance than the previous methods subjectively and objectively.

• Journal of Korean Clinical Health Science
• /
• 제1권1호
• /
• pp.29-34
• /
• 2013

Purpose : This study was to investigate that tongue positions have effect on the cervical range of motion (ROM). Methods : 18 subjects, 20 to 25 years of age, were participated in this study. The tongue positions were neutral position, anterior protrusion, posterior protrusion, superior protrusion, inferior protrusion, left side protrusion and right side protrusion. The neck movements were right side flexion, left side flexion, right rotation and left rotation. The cervical range of motion measured by cervical range of motion instrument (CROM, C9266-49, USA). The changes were analyzed using the paired t-test. SPSSWIN (ver. 20.0) was used for data analysis and the significance level was chosen as ${\alpha}$=0.05. Results : In the lateral flexion, the angle of left lateral flexion increased in anterior protrusion(p<0.05) and right side protrusion(p<0.05) significantly. In the rotation, the angle of right rotation increased in anterior protrusion(p<0.05), posterior protrusion (p<0.05), superior protrusion(p<0.05), inferior protrusion(p<0.05), and left side protrusion (p<0.05) significantly. Conclusions : In conclusion, we found that the tongue positions affected some cervical movements.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 한국지진공학회 2003년도 춘계 학술발표회논문집
• /
• pp.193-199
• /
• 2003

The most cultural heritages are composed of piled multi-block systems which are vulnerable to earthquakes. The stone of low height tends to slide when the excitation such as earthquake is applied and this sliding motion has effects on the whole response of the structure. In this study, analytical method of sliding motion of the piled multi-block systems considering horizontal rotation is developed and compared with shaking table test results. It is shown that the nonlinear analysis of sliding motion of multi-block system leads to satisfactory results.

• The Academic Congress of Korean Shoulder and Elbow Society
• /
• 대한견주관절학회 2009년도 제17차 학술대회
• /
• pp.175-175
• /
• 2009

Despite its importance for the understanding of joint kinematics in vivo, there has been few studies about shoulder joints. The purpose of this study is to analyze the glenohumeral joint during internal and external rotation at 90 degrees of abduction using in vivo noninvasive motion analysis system. MRI was performed for the following seven positions from maximum internal rotation to maximum external rotation at intervals of 30 degrees. We used 3D-gradient echo sequencing (TR: 12 ms, TE: 5.8 ms, 0.8 mm-slice thickness). Our method is based on matching three-dimensional MR images by the similarity of the image intensity. We analyzed the in vivo three-dimensional motions of the glenohumeral and scapulothoracic joint during this motion. In scapla plane, the mean rotation angle of the glenohumeral join was 105.5 degrees ($SD{\pm}39.0^{\circ}$). The mean rotation angle of the scapulothracic joint was 27.5 degrees ($SD\;{\pm}\;7.7^{\circ}$). The contribution ratio is almost 3.8:1 of glenohumeral and scapulothracic joint respectively.

• Journal of The Korean Association For Science Education
• /
• 제33권3호
• /
• pp.664-678
• /
• 2013

This study aims to investigate gifted students' explanations for daily celestial motion from the Earth-based and heliocentric frames of reference. Eleven sixth-grade elementary school students were chosen for this study and data was collected through a questionnaire and an in-depth interview. The collected data was analyzed into celestial objects which are the Sun, the moon and the stars and analyzed based on the Earth-based and heliocentric perspectives again. As a result of the research, most gifted students were able to connect the Earth-based and heliocentric frames of reference with the Sun's daily apparent motion. However, they understood the daily apparent motion of the moon and the stars far less frequently compared to the Sun's motion and could not explain the Earth's rotation clearly. The result of the interview showed that the lack of understanding about the daily celestial motion was caused by inaccurate understanding of the Earth's rotation such as using memorized knowledge learned in school and guessing the answer.

• Korean Journal of Applied Biomechanics
• /
• 제20권2호
• /
• pp.117-127
• /
• 2010

The axes of upper forearm coordinate system have been considered as principal axis of each segment which was component of elbow joint. The purpose of this study was to verify whether the mean direction(principal axis) of instantaneous axes of rotation for pure flexion/extension motion coincided with the flexion/extension axis of upper forearm coordinate system. The same procedure was done for pronation/supination motion. Furthermore, it was tested indirectly that there was an interaction effect between the two rotational motions. The results showed that most segment coordinate axes statistically were not consistent with the mean directions of flexion/extension and pronation/supination axes of rotation. From the results, it would be concluded that the ISB coordinate systems was proved to be a little valid for human movement analysis. There also was an effect of pronation/supination angles on flexion/extension motion.

• Korean Journal of Applied Biomechanics
• /
• 제16권3호
• /
• pp.33-41
• /
• 2006

This study was to analysis three dimension angle of the upper extremity segment and trunk to putting the protector in women bowlers. For this study, the subjects selected 4 players of national and university team. All subjects putted in the same wrist support to satisfy the experiment conditions. To get three dimensions position coordination of swing motion used for 6 ProReflex MCU 240 camera produced by Qualisys. After position coordination calculation, Three dimension angle of the trunk and the upper extremity segment calculated for Matlab 6.5. the result is following; In the trunk motion, there were little differences among the subjects in a flexion and extension change. There were a lot of differences in motion change of the abduction-adduction and internal-external rotation, but the motion types translated to the adduction-abduction-adduction and from the internal rotation toward the external rotation. In the upper arm segment the Flexion and extension showed a consistent motion in the down swing and up swing phase. And the motion change of abduction-adduction and pronation-supination showed a abduction-adduction-abduction and pronation-supination change during swing phase. In the forearm segment changes, it showed a lot of differences among the subjects and a similar change with the upper arm segment. Especially, the hand segment showed a supination motion from the backswing apex to release phase, but for increasing a rotation velocity of ball, the hand segment translated toward pronation in follow throw phase.