• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.171-179
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• 2002

It is well known that the geometry of the articular surface plays a major role in the kinematic and kinetic analysis to understand human knee joint function during motion. The functionality of the knee joint cannot be accurately modeled without considering the effects of sliding and lolling motions. We Present a 3-D human knee joint model considering sliding and rotting motion and major ligaments. We employ more realistic articular geometry using two cam profiles obtained from the extrusion of the sagittal Plain view of the representative Computerized Tomography image of the knee joint compared to the previously reported model. Our model shows good agreement with the already reported experimental results on Prediction of the lines of force through the human joint during gait. The contact point between femur and tibia moves toward the Posterior direction as the knee undergoes flexion, reflecting the coupling of anterior and Posterior motion with flexion/extension. The anterior/posterior displacement of the contact Point on the tibia plateau during one gait cycle is about 16 mm. for the lateral condyle and 25 mm. for the medial condyle using the employed model Also. the femur motion on the tibia undergoes lateral/medial movement about 7 mm. and 10 mm. during one gait cycle for the lateral condyle and medial condyle. respectively. The developed computational model maybe Potentially employed to identify the joint degeneration.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.181-187
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• 2011

The purpose of this study was to identify major factors on pirouette in ballet, and especially angle, Center of Mass(CM) & muscle activity aspects. The data were collected by using Motion Analysis System with 12 cameras to analyze kinematic variables with 120 Hz and Electromyography(EMG; 4,000 Hz) & Force Platform(1,000 Hz) to analyze kinetic variables. The subjects of this study were 8 female ballet dancers. The results as follow. First of all, full extension of knee joint and full plantar flexion of ankle joint appeared at the similar point. Secondly, in the rotational phase, total movement of segments in Good motion is smaller than that of Bad motion(in Good motion, head movement 2.70 cm, right shoulder movement 0.72 cm, left shoulder 4.26 cm, left wrist 17.4 mm smaller than Bad motion). Third, CoP distance of Good motion is 11.76 mm, and CoP distance of Bad motion is 11.76 mm, so Good motion is 5.98 mm smaller). Lastly, Pirouette need more retus femur activity than gastrocnemius activity in extention phase and rotation phase of support leg.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.6
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• pp.584-590
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• 1984

This study is to develop a program, with which the motion of the system can be simulated in view of kinematics and dynamics, and then evaluate functional capabilities of many robots in order to select the most suitable one for any given working conditions. According to the theory of Denavit & Hartenberg, rectangular coordinate is set at each joint in the robot of six joints, as this one is the major concern, and transformation matrices are derived between any two coordinates. The necessary displacement of each joint for executing a given a work is obtained from the position and posture transformation and the in-stantaneous velocity of the joint is got from given velocity distribution of the path. The necessary torque of each joint is finally calculated by Newton-Euler Method. This simulation program is applied to a robot with six rotational joints, Rotational angle and torque to time which has a given motion trajectory are figured and also torque to r.p.m.

• Korean Journal of Applied Biomechanics
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• v.21 no.1
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• pp.57-65
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• 2011

This research was conducted to biomechanically analyze Tippelt motion in parallel bars, and establish technical understanding. To achieve that goal, the performances of the Tippelt acts carried out by five world top-class national gymnasts in the parallel bars 3-dimensional cinematographic analysis and EMG analysis were conducted and following conclusion were obtained. The Tippelt motions of excellent national gymnasts perform tap motion through the down swing of a large circular movements, and perform kick-out motion rapidly extending shoulder joint angle and hip joint angle with the trunk in a position close to perpendicular position at the vertical downwardness of the grasping the bars. At this time, if handstand starting the movement is too delayed or rapidly down swung, it was shown that from the initial falling, unnecessary muscular power was wasted in trapezius, anterior deltoid, erector spinae, latissimus dorsi, upper rectus abdominis, lower rectus abdominis. The muscular parts in tap motion generating muscle action potential were pectoralis major, rectus femoris, upper rectus abdominis, lower rectus abdominis, and those in kick-out motion were upper rectus abdominis, lower rectus abdominis, trapezius and anterior deltoid.

• The Journal of Korean Physical Therapy
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• v.34 no.5
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• pp.255-266
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• 2022

Purpose: This study sought to study the effects of cross-legged sitting posture on joint motion. It also examined the correlation between the changes in the joint range of motion, musculoskeletal symptoms, and facial asymmetry. Methods: The Acumar Digital Inclinometer (Lafayette Instrument Company, USA) was used to measure the range of motion (ROM). We measured the flexion and extension of the cervical, thoracic, and lumbar spine using a dual inclinometer, and measured the ROM of the shoulder and hip joint with a single inclinometer. The Likert scale questionnaire was used to investigate musculoskeletal symptoms and facial asymmetry. Results: The data analysis was performed using the Jamovi version 1.6.23 statistical software. After confirming the normality of the ROM with descriptive statistics, it was compared with the normal ROM through a one-sample t-test. Correlation matrix analysis was performed to confirm the association between facial asymmetry and musculoskeletal symptoms. The result of the one-sample t-test showed a significant increase in the thoracic spine extension and right and left hip external rotation (p<0.001^***), while most other joints were restricted. As per the frequency analysis, facial asymmetry was found to be 81.70%. Conclusion: The independent variable, namely cross-legged sitting posture led to an increase in ROM. The study also suggests that facial asymmetry and musculoskeletal symptoms could occur. Therefore, to prevent the increase and limitation of ROM and to prevent the occurrence of facial asymmetry and musculoskeletal symptoms, it is suggested that the usual cross-legged sitting posture should be avoided.

• Korean Journal of Applied Biomechanics
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• v.29 no.2
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• pp.89-96
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• 2019

Objective: The purpose of this study was to investigate biomechanical comparisons of kettlebell two-arm swings after different somatosensory interventions on joint ranges of motion (ROM) and muscle activations. Method: Fourteen kettelbell novices (age: $22.92{\pm}3.23yrs$, mass: $75.75{\pm}9.94kg$, height: $172.03{\pm}5.49cm$), consisting of male college students, participated in this study and performed two-arm kettlebell swings in different conditions. Three different somatosensory interventions were the applications of heavy mass kettlebell (20 kg), taping on gluteus muscles, and unstable mat condition. All subjects performed pre-intervention swings and post-intervention swings, respectively. Statistical analysis were performed on results of joint kinematics and electromyographies of major muscles. Results: Results showed significant increases in ROM of hip and decreases in ROM of shoulder after unstable mat trials. In addition, the application of unstable mat during kettlebell swings induced higher muscle activations in gluteus maximus muscle during only upward phase of two-arm kettlebell swings. Conclusion: For beginner, the application of unstable surface would increase in hip joint ranges of motion with enhancement of gluteus muscles.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.347-354
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• 2021

In the equipment industry such as chemical plants, high temperature, high pressure, and toxic fluids move between various facilities through piping. The movement and damage of pipes due to changes in the surrounding environment such as temperature changes, vibrations, earthquakes, and ground subsidence often lead to major accidents involving personal injury. In order to prevent such an accident, various types of expansion joints are used to absorb and supplement various shocks applied to the pipe to prevent accidents in advance. Therefore, it is very important to measure the deformation of the used expansion joint and predict its lifespan to prevent a major accident. In this paper, the deformation of the expansion joint was understood as a kind of motion, and the change was measured using a Hall Effect Sensor and a 9-Axis Sensor. In addition, we studied a system that can predict the deformation of expansion joints by collecting and analyzing the measured data using a general-purpose microcomputer (Arduino Board) and C language.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.235-239
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• 2015

The purpose of this study was to investigate the unstable plate system for the advanced balance ability. 7 male volunteers (age $33.7{\pm}1.2$ years, height $174.7{\pm}3.8cm$, weight $86.0{\pm}3.6kg$, BMI $28.2{\pm}2.0kg/m^2$) performed the partial squat motion on the shape of CAP type(${\cap}$) and BOWL type(${\cup}$) plate system. The range of motion (ROM) and muscle activation were acquired by the motion analysis system and the EMG system. Results of ROMs of the CAP type plate system were shown the widely range of the deviation in the ankle joint on the sagittal plane (sagittal plane - hip joint $10.7^{\circ}$ > $5.4^{\circ}$, knee joint $16.3^{\circ}$ > $6.4^{\circ}$, ankle joint $18.8^{\circ}$ > $6.3^{\circ}$ ; transverse plane - hip joint $3.5^{\circ}$ > $1.8^{\circ}$, knee joint $5.3^{\circ}$ > $3.4^{\circ}$, ankle joint $11.3^{\circ}$ > $5.3^{\circ}$ ; frontal plane - hip joint $0.9^{\circ}$ > $0.5^{\circ}$, knee joint $0.8^{\circ}$ > $0.6^{\circ}$, ankle joint $4.8^{\circ}$ > $3.7^{\circ}$). Muscle activation results of the CAP type plate system were indicated higher in major muscles for balance performance than the BOWL type plate system (vastus lateralis 0.90 > 0.62, peroneus longus 0.49 > 0.21, biceps femoris 0.38 > 0.14, gastrocnemius 0.11 > 0.05). These findings may indicate that the CAP type plate system would expect better effectiveness in perform the balance training. This paper is primary study for developing balance skills enhancement training device.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.141-148
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• 2013

The purpose of this study was to investigate the scapulothoracic joint movement between different weight bearing contributing to effective bench press exercise. Ten male subjects participated in this study. All subjects were tested on the flat bench press machine which modified weight (50% and 70% of 1RM) and subjects were performed two different conditions(none protraction condition and protraction condition). Weight bar height and vertical velocity, EMG activation was measured using 3D motion capture system and wireless EMG analysis system. As the results, none protraction condition showed that it is more concentrate better pectoralis major muscle activation than protraction condition and middle pectoralis major, anterior deltoid and triceps brachii was significant higher integrated EMG in 70% of 1RM condition. In conclusion, limited scapulothoracic joint movement was more effective activated pectoralis major muscle all the weight through, while we could not find that it was not affected integrated EMG on eight muslces related to shoulder complex between scapulothracic joint movement conditions.

• Journal of Korean Physical Therapy Science
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• v.5 no.3
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• pp.697-706
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• 1998

Motion at the sacroiliac joints(SIJ) has been reported in the medical literature since the mid-19th century. However, for many years authorities vie~d that no movement occurred at the sacroiliac joints and therefore were not clinically significant. Recent contributions from both the basic and clinical sciences caused a change in perception of the role of the sacroiloiac joint in low back pain(LBP). Movement within the sacroiliac joint is now generally recognized, although it is only a small amount. Controversy continues as to the type of motion available and the axes of motion, and continues as to the ability of a clinician to identify a significant sacroiliac dysfunction. Dysfunction of the pelvic girdle is complex and not easily understood. It is common to find serveral dysfunctions within the same pelvic girdle. Each needs to be individually diagnosed and appropriately treated. The diagnostic and therapeutic system designed by Philip E. Greenmam, D. O. allows the operator to deal with any combination of physical findings that are found within the pelvic girdle Restoration of pelvic girdle function within the walking cycle is a major therapeutic goal, particularly from the biomechanical postural-structural model.