• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.1-9
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• 2014

The purpose of this study was to investigate the muscle mechanical properties of the pelvic axial pre-rotational movement for the Jireugi in the Taekwondo Juchumseogi stance. Eleven elite Taekwondo Poomsae athletes participated. Each participant performed 5 right hand Jireugi in Juchumseogi stance as fast and strong as possible while their motion was recorded by a 3D motion analysis system and the ground reaction forces by two force plates. The power and work of the muscular group surrounding the waist were analyzed to verify the effect of the stretch-shortening cycle (SSC) theory. The cause of the greater power seems to be the application of the SSC by the muscles surrounding the waist during the preparation phase of the pre-rotation group. For the none pre-rotation group, they only used the concentric contraction of the muscles surrounding the waist. Because the pre-rotation group used the SSC theory, they had the effect of shortening of the range of movement, creating a fast and more powerful rotation, thus anticipating the increase the magnitude of impact.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.115-122
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• 2018

The success of the total hip arthroplasty is revealed as initial stability, range of motion, and long term pain, etc. Depending upon choice of implantation options such as femoral neck offset, diameter of the femoral head, the lateral opening tilt. Especially the impingement between femoral head component and acetabular cup limits the range of motion of the hip. In this sense, estimation or evaluation of the range of motion before and after the total hip arthroplasty is important. This study provides the details of a computer simulation technique for the hip range of motion of intact hip as well as arthroplasty. The suggested method defines the hip rotation center and rotation axes for flexion and abduction, respectively. The simulation uses CT-based reconstructed 3D models and an STL treating software. The abduction angle of the hip is defined as the superolateral rotation angle from sagittal plane. The flexion angle of the hip is defined as the superoanterior angle from the coronal plane. The maximum abduction angle is found as the maximum rotation angle by which the femoral head can rotate superolaterally about the anterior-posterior axis without impingement. The maximum flexion angle is found as the maximum rotation angle by which the femoral head can rotate superoanteriorly about the medial-lateral axis without impingement. Compared to the normal hip, the total hip replacement hip showed decreased abduction by 60 degrees and decreased flexion by 4 degrees. This measured value implies that the proposed measurement technique can make surgeons find a modification of increase in the femoral neck offset or femoral head, to secure larger range of motion.

• Journal of Korean Physical Therapy Science
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• v.13 no.1
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• pp.21-27
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• 2006

The purpose of this study was to identify the above mentioned therapy on the reduction of functional leg length inequality, by the manipulation(Thonpson technique). In 8 patients who have been chronically ill with low back pain and functional leg length inequality, for past 12 weeks, we analyzed and observed the progress of symptom and sign on pelvis(femur head line level, ilium length, ilium rotation), using by X-ray. The results after 12 week treatment, compared with before treatment, were as follows : 1. The improved in femur head line in the manipulation after 12 week treatment was very significant(p<.01) 2. The improved in ilium length in the manipulation after 12 week treatment was very significant(p<.01) 3. The improved in ilium rotation in the manipulation after 12 week treatment was significant(p<.05).

• Journal of Digital Convergence
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• v.17 no.12
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• pp.555-563
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• 2019

This study was to provide quantitative basic data on the forehand and backhand throw movements of flying disks. For this purpose, the kinematic variables were calculated using the three-dimensional motion analysis system. A comprehensive analysis of the study variables showed that it is important to throw flying disks accurately as well as far away, so in P2 and P3 it is necessary to control forward movement and concentrate on the rotation of the joints. In addition, rotational force transfer from pelvis to body is considered important for efficient rotational movement. The forehand was found to mainly utilize the movement of the upper extremity joint to perform throwing motion, while the backhand throw was found to be relatively utilized for the rotation of the torso and pelvis. Based on the quantitative data of this study, we hope that it can be used as a basic material for on-site training of Flying Discs.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.132-137
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• 2016

Objective: Eversion of the foot is created with internal rotation of the shank, and inversion of the foot is created with external rotation of the shank. The purpose of the study was to investigate the effect of continuous changes in the angle of the subtalar joint on lower extremity alignments. Design: Cross-sectional study. Methods: Seventeen healthy young adult subjects recruited. The subjects were asked to stand up in a natural standing position on a footplate with eye open and equal weight on each foot for 10s in two different conditions: The right subtalar joint was everted continuously $0^{\circ}-20^{\circ}$ and in separate segments of $0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$. The averages of three trials were used. The observation of the changes in the lower extremity was performed with the use of 3-dimensional motion analysis. For data analysis, the SPSS 18.0 software using paired t-test and repeated measures analysis of variance (ANOVA) was applied. Results: The angle was significantly increased at the horizontal rotation angle of the shank, thigh, and ankle without anterior rotation of the pelvis (p<0.05). The maximum horizontal rotation angle at the thigh on $20^{\circ}$ was $-4.52^{\circ}$ in static, and $-3.10^{\circ}$ in the dynamic conditions compared to $0^{\circ}$. Conclusions: Increased unilateral foot pronation, thigh, shank, ankle horizontal rotation variance was significantly effective. The observation of the changes in foot abduction with the use of a 3-dimensional motion analysis augmented in predicting the angle values of each segment of the lower extremity. In further studies, a comparison of the right and left subtalar joints need to be investigated.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.2
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• pp.47-52
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• 2015

Background: The objective of this study was to compare dysmenorrhea with pelvic alignment, hip joint range of motion about 20's female university students. Sixty two female students participated in this study. To investigate the measure of dysmenorrhea, we used modified menstrual distress questionnaire (MMDQ) and numerric rating scale (NRS). The pelvic alignment was assessed by using the palpation meter. The active range of motion (ROM) were assessed by measuring the flexion, extension, abduction, adduction, internal rotation and external rotation. Each measurement was assessed by goniometer. The data were analyzed by calculating independent T-test. Consequently, As the increase of dysmenorrhea, we observed significantly the increase of pelvic anterior tilt in right and left pelvic (p<.05). Otherwise, as the increase of dysmenorrhea, range of motion of hip joint was significantly limited in right and left external rotation (p<.05). Thus, this study provides young female with valuable information about dysmenorrhea.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.133-145
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• 2007

The purpose of this paper was to compare of difference between energy walking and normal walking. Subjects were selected 8 male undergraduates. The kinematic variables of a pelvis and a thorax were analysed at the take off and contact with 3d cinematography. In addition to the variables, the phase plot angle was calculated in order to definite characteristics in the phase space. The pelvic angle and angular velocity showed significant differences in the flexion/extension between two walking patterns. The pelvic angle and angular velocity were increasing when walking speed was increasing and magnitude of the variables of energy walking was larger than corresponding values for normal walking. On the other hand, the thoracic angle demonstrated significant differences in the flexion/extension and rotation between two walking patterns. The angles of energy walking were smaller in the flexion/extension and were larger in the rotation than the angle of normal walking. The kinematic characteristics of energy walking were also showed clearly significant differences in the range of motion and the relative angle of the trunk. The angle of phase plot only showed demonstrated a significant difference in the rotation at contact between the two walking patterns.

• Journal of International Academy of Physical Therapy Research
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• v.9 no.1
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• pp.1381-1386
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• 2018

The purpose of this study is to investigate the effect of pelvic, Lumbar spine and Cervical spine manipulation on the joint position sense in normal adults. Thirty normal adults were divided into an experimental group of 15 subjects and a control group of 15 subjects. The experimental group was treated with pelvic, Lumbar spine and Cervical spine manipulation with massage, whereas the control group received only massage. Both groups were evaluated in terms of joint position errors (JPEs) using a digital dual clinometer before and after the experiment. The comparison of the JPEs of the experimental group and the control group before and after the experiment showed that the experimental group's cervical spine results were significantly different in the flexion, left lateral flexion, and right rotation (p < .05) and lumbar spine results were significantly different in the flexion and extension (p < .05), but the control group's results were not statistically significant in all items (p > .05). The pelvic, lumbar spine and cervical spine manipulation makes an effect on the joint position sense in normal adults. The findings of this study suggest that the pelvis, lumbar spine and cervical spine manipulation improve the motor ability in people with low joint position sense.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.97-104
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• 2019

Objective: The aim of this study was to investigate the strategies for avoiding moving and stationary walker using body segments during walking. Method: Ten healthy young adults (10 males, age: $24.40{\pm}0.49yrs$, height: $175.80{\pm}5.22cm$, body mass: $70.30{\pm}5.22kg$) participated in this study. Each participant was asked to perform a task to avoid collisions with another walker who was moving or stationary during walking on the 10 m walkway. Both walkers were performed at natural self-selected walking speed. Results: Medio-lateral avoidance displacement of the trunk and the pelvis were significantly increased when avoiding a stationary walker (p<.05). There were no significant differences in medio-lateral center of mass trajectory. Rotation angle of trunk, pelvis and foot on the vertical axis were significantly increased when avoiding a stationary walker (p<.05). Conclusion: Based on our results, when another walker moves continuously, the walker recognizes another walker as the object of social interaction and performs the avoidance strategies while expecting the cooperative distance. On the other hand, when another walker is stopped, it is determined that the walker has an obligation to avoid, and the walker performs a relatively safer avoidance strategy.

• Korean Journal of Applied Biomechanics
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• v.22 no.3
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• pp.277-284
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• 2012

The purpose of this study was to find out the changes in beginners' batting movements after taking undergraduate baseball lectures, by comparing and analyzing the speed of bat, the angle of body and its segments, the angular velocity and so on. For this purpose, the author picked up five undergraduates who had not taken baseball lectures, and conducted three-dimension computerized tomography twice on them, that is, before and after taking baseball classes, with eight infrared cameras and two force platforms. The conclusions are, first, the time required for swing was shortened after taking the classes. Second, the maximum velocity of the bat-end was increased. Third, at the time of impact, while the rotation angles of the pelvis and the tip of left foot were increased, the left elbow had more flexion after the classes. Fourth, the size of ground reaction force was increased at the point of swing where the ground reaction force of left foot became maximized. As we can infer from these conclusions, beginners' hitting movements before taking baseball classes tended to swing only with the arms, without waist rotation and weight shift of the lower body, but after the classes, their movements were proved to be corrected into the swing using the lower body. For the future studies, the author expects a research in a close to real environment by using pitching machine.