• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.1-10
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• 2005

G. B. LEE, A. S. GWON, The Research for Using methodof GRF (Ground Reaction Force) on Rotational Movement in Arabesque. Korean Journal of Sport Biomechanics, Vol. 15, No. 2, pp.1-10, 2005. As, in relation to all movements of a human being, the movements such as mutually walking, running, rotating, and jumping are attained endlessly through the ground amid the interaction with the ground, in terms of the harmonious movement of the upper limbs and the lower limbs, related to the basic movement in ballet, the type of a movement depends on the size and direction of the force that presses down the ground (Fz, Fx, Fy) amid the interaction with the ground. Therefore, aiming to correctly and efficiently perform a rotational movement in Arabesque, this study analyzed factors of the force manifestation through GRF (Ground Reaction Force), by dividing into preparing, stepping, standing, rotating, and finishing stages (events (1) ${\sim}$ (5)), targeting the subjects of 4 elite female students who majored in ballet. 1. At the No.5 position of the preparing stage, It is necessary that support the ground with left and right foot balance, 2. As the stepping stage is the phase ranging from the event (2), in which a plie movement of bending a knee is started, to the event (3) of stretching a knee, Rebunding motion is not good, and One have a position with ankle and knee flextion condition in order to stretch strengthly in event (3) position 3. At the event (1) position, It is necessary that exert the Fz reaction force at the event (3) position. Because large stretch force help to have a toe on position easily and show a active motion 4. In order to have a stand and rotation motion smoothly, One need a muscle strength training for ankle extension, knee extension, control horizental force

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.472-478
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• 2011

The purpose of this study was to analyze the kinetic effect of Soft-$golf^{TM}$ instrument on the human body structure. To analyze the kinetic effect of Soft-$golf^{TM}$ instrument, Golf swing using Soft-$golf^{TM}$ instrument and regular golf instrument was captured. And then Upper limbs and lumbar joint torques was calculated via computer simulation. Five man participated this study. Subjects performed golf swing using a regular golf and Soft-$golf^{TM}$ instrument. Golf swing motion was captured using three position sensor, active infrared LED maker and force plate. Golf swing model was generated and simulated using ADAMS/LifeMOD program. As a results, joint torque during Soft-golf swing were lower than regular golf swing. Thus soft-golf swing have joint load lower than regular golf swing and contribute to reduce joint injury.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.527-535
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• 2016

Statistical optimization algorithms have been variously developed to estimate the 3D shape and motion. However, statistical approaches are limited to analyze the sensitive effects of SfM(Shape from Motion) according to the camera's geometrical position or viewing angles and so on. This paper propose the quantitative estimation method about the uncertainties of an observation matrix by using camera imaging configuration factors predict the reconstruction ambiguities in SfM. This is a very efficient method to predict the final reconstruction performance of SfM algorithm. Moreover, the important point is that our method show how to derive the active guidelines in order to set the camera imaging configurations which can be expected to lead the reasonable reconstruction results. The experimental results verify the quantitative estimates of an observation matrix by using camera imaging configurations and confirm the effectiveness of our algorithm.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.7
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• pp.620-625
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• 2013

Mammals such as dogs and cheetahs change their gait from trot to gallop as they run faster. However, lizards always trot for various speeds of running. When mammals run slowly with trot gait, their fore leg and hind leg generate the required force for acceleration or deceleration such that the yaw moments created by these forces cancel each other. On the other hand, when lizards run slowly, their fore legs and hind legs generate the forces for deceleration and acceleration, respectively. In this paper, the yaw motion of a lizard model is controlled by the movement of their waist and tail, and the reaction moment from the ground produced by the hind legs in simulation. The simulation uses the whole body dynamics of a lizard model, which consists of 4 links based on the Callisaurus draconoides. The results show that the simulated trotting of the model is similar to that of a real lizard when the movement of the model is optimized to minimize the reaction moment from the ground. It means that the body of a lizard moves in such a way that the reaction moment from the ground is minimized. This demonstrates our hypothesis on how lizards trot using body motion.

• Physical Therapy Korea
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• v.22 no.2
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• pp.1-10
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• 2015

The common features of walking in patients with stroke include decreased gait velocity and increased asymmetrical gait pattern. The purpose of this study was to identify important factors related to impairments in gait velocity and asymmetry in chronic stroke patients. The subjects were 30 independently ambulating subjects with chronic stroke. The subjects' impairments were examined, including the isokinetic peak torque of knee extensors, knee flexors, ankle plantarflexors, and ankle dorsiflexors. Passive and active ranges of motion (ROM) of the ankle joint, ankle plantarflexor spasticity, joint position senses of the knee and ankle joint, and balance were examined together. In addition, gait velocity and temporal and spatial asymmetry were evaluated with subjects walking at their comfortable speed. Pearson correlations and multiple regressions were used to measure the relationships between impairments and gait speed and impairments and asymmetry. Regression analyses revealed that ankle passive ROM and peak torque of knee flexors were important factors for gait velocity ($R^2=.41$), while ankle passive ROM was the most important determinant for temporal asymmetry ($R^2=.35$). In addition, knee extensor peak torque was the most significant factor for gait spatial asymmetry ($R^2=.17$). Limitation in ankle passive ROM and weakness of the knee flexor were major contributors to slow gait velocity. Moreover, limited passive ROM in the ankle influenced the level of temporal gait asymmetry in chronic stroke patients. Our findings suggest that stroke rehabilitation programs aiming to improve gait velocity and temporal asymmetry should include stretching exercise for the ankle joint.

• The Journal of Korean Physical Therapy
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• v.23 no.5
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• pp.49-56
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• 2011

Purpose: The purpose of this study was to investigate the kinematic characteristics and muscle activities during the following two conditions: transition from half-kneel to standing on the affected leg and non-affected leg. Methods: Twenty-one hemiplegic patients participated in the study. A motion analysis system was used to record the range of motion and angle velocity of the hip, knee and ankle from the half-kneel to the standing position. Electromyography was used to record the activity of 4 muscles. Results: The statistical analysis showed that the minimum ROM of the hip joint was less on the affected leg during transition from half-kneel to standing. However, the minimum ROM of the knee and ankle joints was less on the non-affected leg during transition from half-kneel to standing. The angle velocity of the knee and ankle joints was less during transition from half kneeling to standing on the non-affected leg. Muscle activity of the rectus femoris and tibialis anterior was less while moving from half-kneel to the standing position on the affected leg. Conclusion: These results show that greater active ROM of the knee and ankle was required on the affected leg for transition from half-kneel to the standing position than for normal gait. Muscle activity of the rectus femoris and tibialis anterior is normally required for movement from the half-kneel to the standing position during normal gait. Further studies are needed to investigate the antigravity movement in healthy subjects and hemiplegic patients in order to completely understand the normal and abnormal movement from the half-kneel to the standing position.

• Physical Therapy Rehabilitation Science
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• v.8 no.4
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• pp.210-217
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• 2019

Objective: This study was conducted to compare the immediate effect of hamstring stretching techniques of static stretching, proprioceptive neuromuscular facilitation (PNF) hold-relax and PNF irradiation on the hamstring muscle. Design: Three-group pretest-posttest design. Methods: Fifty-one subjects with shortened hamstrings were randomly assigned to the static stretching group (n=17), PNF hold-relax group (n=17), and the PNF irradiation group (n=17). All subjects performed an active knee extension (AKE) test to assess for the lower extremity with a shortened hamstring. The static stretching group performed stretches by lifting their leg to the maximum extent (3 times, 30 seconds). The PNF hold-relax group performed maximal isometric contraction against the experimenter's resistance (3 times, 10 seconds). The PNF irradiation group performed maximum isometric contraction against the experimenter's resistance toward the direction of the body (5 times, 5 seconds). The pre and post-tests measured range of motion (ROM), pressure pain thresholds (PPT) and muscle tone. Results: There were significant differences in ROM and PPT between pre and post intervention in each group (p<0.05). There was a significant difference only in the ROM among groups (p<0.05). Post-hoc analysis showed that the changes in ROM occurred in the order of the PNF hold-relax group, static stretching group and PNF irradiation group (p<0.05). Conclusions: The findings of this study suggest that the PNF irradiation technique may improve ROM and may be used to improve ROM similar to other stretching techniques. Therefore, the PNF irradiation technique could be included in stretching programs and can be used as a suitable stretching method depending on the situation.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.132-138
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• 1997

The purpose of this study is to compare the results between conventional and accelerated rehabilitation program following ACL reconstruction using bone-patellar tendon-bone. Conventional rehabilitation focused on protecting the new ligament by blocking terminal extension and avoiding active quadriceps function in the terminal degrees of extension. But there is current trend toward early postoperative mobilization and intensive. so called 'accelerated', rehabilitation stressing hyperextension of the knee. The results of intraarticular ACL reconstruction with conventional and accelerated rehabilitation were prospectively compared for one year postoperatively in a series of 27 patients. Range of motion and thigh circumference were checked preoperatively, and weekly up to 8 weeks, 3 months. 6 months, and 1 year postoperatively. Stress radiologic test, KT-1000 arthrometer. Cybex II dynamometer were checked in preoperatively, and 3 months, 6 months, and 1 year postoperatively. There were no differences of objective stability and restoration of muscle power. But the accelerated group had a low incidence of extension loss. excellent range of motion, and less difference of thigh circumference. We concluded that accelerated rehabilitation program is recommendable due to superiority in terms of range of motion, especially less extension loss without increasing laxity of knee joint.

• Clinics in Shoulder and Elbow
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• v.1 no.2
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• pp.242-249
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• 1998

Stiffness of the elbow joint is relatively common after trauma, ectopic ossification, bum, postoperative scar, and etc. Mild flexion deformity can be reduced by use of active or passive motion exercise, dynamic sling, hinged distractor device, or turnbuckle orthosis. But these methods have disadvantages of difficulty in gaining acceptable range of motion only with stretching exercise, re-contracture after conservative managements and poor results that flexion contracture remained. The common described operative exposures for treatment of the stiff elbow are anterior, lateral, posterior, and medial approach. Through Anterior, lateral and medial approach each has not access to all compartments of the elbow. But, posterior approach has benefits that access to posterior, medial and lateral aspects of the elbow and as needed, fenestration to the olecranon fossa that produces a communication between the anterior and posterior compartments of the elbow are possible. From June 1991 through April 1997, 11 patients who had posttraumatic stiff elbow, were treated with debridement arthroplasty through the posterior approach. The purpose of this study are to introduce technique of the debridement arthroplasty and to evaluate final outcomes. With regarding to preoperative pain degree, mild degree matches to 3 cases, moderate to 3 cases, and severe to 2 cases. In preoperative motion, flexion was average 85° and extension was 30°. Postoperatively nine patients had got the complete relief of pain and two patients continued to have mild pain intermittentely. Postoperative flexion improved to 127° and extension to 2°, so that elbow flexion had improved by an average of 42° and elbow extension by 28°. On the objective scale all patients had good or excellent results and they all felt that they were improved by operation. Debridement arthroplasty is one of excellent procedures for the intractable stiff elbow if it is not unstable or it has not incongrous. But it need a meticulous operative technique and a well-programmed rehabilitation.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.69-80
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• 2015

PURPOSE: The purpose of the present study was to apply joint mobilization in a sitting position and in a prone position to patients with acute mechanical neck pain and compare the immediate treatment effects in these two positions. METHODS: After the baseline was assessed, 46 patients were randomly assigned to two groups: experimental group I ($n_1=23$) for joint mobilization in the sitting position and experimental group II ($n_2=23$) for joint mobilization in the prone position at the symptomatic cervical level. The patients in both groups received treatment by unilateral posterior-anterior gliding for 30 seconds per trial, 10 trials per session, for a total of 5 minutes, and two trials of 10 active extending motions with distraction per trial. RESULTS: In the Wilcoxon signed-rank test, all the pain and physical function variables were significantly improved after intervention in both groups (p<.05). In the Mann-Whitney U test, which compared the differences before and after the intervention between the two groups, experimental group I showed significant improvement over experimental group II in resting pain (p<.01), satisfaction with the treatment (p=.01), left rotation (p<.01) and CCFE (p<.01). In the analysis of covariance results, experimental group I showed significant improvement over experimental group II in the most painful motion pain (p<.01) and the most painful quadrant motion pain (p<.01). CONCLUSION: These outcomes suggest that joint mobilization should be applied in sitting positions for patients with acute mechanical neck pain that feel pain during sustained positions, extension or rotation.