• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.16-23
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• 2018

Postural instability can increase the likelihood of hazardous slip and fall accidents in workplaces. The present study intended to extend understanding of the effect of abnormal neck posture on postural control during quiet standing. The effect of body fatigue on the postural control was also of primary concern. Twelve healthy undergraduate students volunteered to participate in the experiment. Standing on a force platform with the neck neutral, flexed, extended, or rotated, subjects' center of pressures (COP) were measured under the two levels of body fatigue. For the fatigue condition, Subjects exercised in a treadmill to meet the predetermined level of body fatigue. Analyzing the position coordinates of COPs, the length of postural sway path was assessed in both medio-lateral (ML) axis and anterior-posterior (AP) axis. Results showed that, in AP direction, neck extension or rotation significantly increased the sway length as compared with neck neutral. Neck extension led to greater sway length compared to neck rotation. Neck flexion did not differ from neck neutral. The sway length in the AP direction also became significantly larger as the body fatigue accumulated after treadmill exercise. In ML direction, as compared to neutral posture, the neck extension, flexion, or rotation did not significantly affect the length of postural sway path. However, the sway length seemed to increase marginally with the neck extended during the fatigued condition. This study demonstrates that abnormal neck posture may interfere with postural control during standing. The ability to maintain postural stability decreases significantly with the neck extended or rotated. Body fatigue leads to postural instability further.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.113-121
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• 2007

The purpose of this study was to determine the effect of three different plates($0^{\circ}$, $10^{\circ$}, $20^{\circ}$)under heels on the lower limb muscles and erector spinae during squat exercise. Ten high school korean traditional wrestling players(age: $18.5{\pm}0.7$, weight: $1972.2{\pm}128.5N$, height: $177.8{\pm}6.0cm$, weight of barbell: $1004.5{\pm}132.4N$) performed squat exercise using three different tilting plates under heels at a cadence of 40beats/sec with 80% one repetition maximum load. Surface electrodes were placed on the participants' left and right erector spinae, and rectus femoris, vastus medialis, vastus lateralis, tibialis anterior, biceps femoris, medial gastrocnemius, and lateral gastrocnemius in the right lower extremity. One S-VHS camcorder(Panasonic AG456, 60fields/s) was placed 10m to the side of the participant. To synchronize the video and EMG data, a synchronization unit was used for this study. Average and Peak IEMG values were determined for each participant. For each variable, a one-way analysis of variance was used to determine whether there were significant differences among three different tilting plates under heels. When a significant difference was found in plates type, post hoc analyses were performed using the Tukey procedure. A confidence level of p<.05 was used to determine statistical significance. As a result of this study, maximum nEMG values of the tibialis anterior in $0^{\circ}$ plates was significantly higher than the corresponding values for the other plates during the knee extension. This increased activation in the tibialis anterior muscle indicates an increase in displacement of center of gravity of body. It is very likely that additional muscle activation are needed to stop the forward and backward movement. The results also showed that muscular activities of quadriceps femoris and erector spinae were decreased with increasing angle of plates. This suggests that increasing angle of plate may help to sustain the balance and posture of squat exercise. It is considered that very few significant differences were found among three different plates($0^{\circ}$, $10^{\circ}$, $20^{\circ}$) since elite players with much experience in squat exercise, were chosen as a participant of this study. In order to obtain meaningful results regarding the tilting angle of heel plates in squat exercise, kinetic and 3D kinematic analysis will be needed in the future study.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.1
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• pp.47-56
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• 2020

Purpose : The purpose of this study was to determine the effects of upper extremity volume, pain, and range of motion after participation in thera-band exercises according to the hand grip type in patients with breast cancer with upper extremity edema. We also aimed to determine the most efficient type of grip. Methods : The subjects were 10 female patients diagnosed with stage 2 breast cancer who had stage 2 lymphedema. Randomly, 5 patients each were allocated to the experimental and control groups. For six weeks, the patients in both the experimental and control groups exercised daily. In both groups, manual lymph drainage was applied for 1 hour. Afterward, patients in the experimental group placed their hands in the thera-band ring and exercised with their fingers outstretched. Patients in the control group exercised while holding the thera-band ring with a finger. Both the experimental group and the control group underwent measurements of the circumference of the upper extremity, pain, and range of motion of the shoulder joint at weeks 1, 2, 4, and 6 before and after exercise. Results : The upper arm circumference decreased by more in the experimental group in all weeks than before than that in the control group, and there was a statistically significant difference at 6 weeks. Compared with the difference between pre-exercise and 6 weeks post-exercise, the change in pain significantly decreased in the experimental group and showed a statistically significant difference. The shoulder range of motion increased in extension, external rotation, and internal rotation compared with that in the control group, and there was a statistically significant difference. Although the operating range increased in flexion and abduction, there were no statistically significant differences. Conclusion : In this study, we found that thera-band exercises with an open-hand grip are more efficient than thera-band exercises with a closed-hand grip in edema reduction, pain, and range of motion. In addition, it was found that it was more effective to continue the thera-band exercises with open-hand grip extended for at least 6 weeks rather than for a short time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6099-6111
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• 2015

This study was a systematic review and meta-analysis comparing the effects of aquatic exercise and land-based exercise in the treatment of knee osteoarthritis. 7 studies (n=449) met selection and exclusion criteria out of 287 potential studies obtained from the literature search via Ovid-Medline, Cochrane Library CENTRAL, CINAHL, RISS and KISS. The overall risk of bias of selected studies using SIGN (Scottish Intercollegiate Guidelines Network) checklist for randomized controlled trials (RCT) was regarded as low. As a result of meta analysis, Standardized Mean Difference (SMD) for pain was -0.26(95% CI -0.49, -0.03, p=0.03, $I^2=14%$), which implies that aquatic exercise groups had significant less pain than land-based exercise groups. On the other hand, there was no significant difference between aquatic exercise groups and land based exercise groups for flexion Range of Motion (ROM) (-0.12, 95% CI -0.51, 0.27, p=0.53, $I^2=0%$), extension ROM (-0.04, 95% CI -0.55, 0.48, p=0.89, $I^2=43%$), physical function (-0.12, 95% CI -0.44, 0.19, p=0.44, $I^2=0%$), Quality of Life (QOL) (-0.15, 95% CI -0.54, 0.24, p=0.46, $I^2=0%$). This study has some limitations due to few RCTs comparing aquatic exercise groups and land-based exercise groups in the treatment of knee osteoarthritis. Therefore, further RCTs should be conducted along with long-term outcomes.

• STI Policy Review
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• v.2 no.2
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• pp.45-54
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• 2011

This paper develops a recursive multinomial probit model and describes its estimation method. The recursive multinomial probit model is an extension of a recursive bivariate probit model. The main difference between the two models is that a single decision among two or more alternatives can be considered in each choice equation in the proposed model. The recursive multinomial probit model is developed based on a standard framework of the multinomial probit model and a Bayesian approach with a Gibbs sampling is adopted for the estimation. The simulation exercise with artificial data sets is showed that the model performed well. Since the recursive multinomial probit model can be applied to analyze the causal relationship between discrete dependent variables with more than two outcomes, the model can play an important role in extending the methodology of the causal relationship analysis in innovation research.

• Korean Journal of Acupuncture
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• v.25 no.2
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• pp.115-123
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• 2008

Objectives : The aim of this stuty is to investigate the effect of acupuncture at $Yanggn\bar{u}ngch'\check{o}n$ (G34) on the muscle fatigue. Methods : Subjects were asked to perform the elbow flexion and extension to induce the muscle fatigue. Sample group of 16 healthy subjects had acupuncture on $Yanggn\bar{u}ngch'\check{o}n$ (G34) during the resting time, while control group of 13 healthy subjects did not. Surface electromyography (sEMG) was measured after exercise and rest to record muscle fatigue. Results : Acupuncture at $Yanggn\bar{u}ngch'\check{o}n$ (G34) is effective for decreasing the muscle fatigue.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.1 no.1
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• pp.99-104
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• 1995

Markolf and Morris suggests that the deranged disk and torn annulus have an exellent recovery ability from the position of spine extension, where the posterior annulus is not under stress and the gel can move anterioly. McKenzie explains side gliding as a combination of rotation and side bending, his clinical studies indicate that side-gliding can gel laterally. In conclusion, the prone unilateral traction on the opposite side from the patient's pain along with the other treatment appered to have helped reduce those patient's pain. The method of treatment described in this report is suggested for Korean physical therapists who treat patients suspected of posterolateral herniated nucleus pulposus.

• Journal of Korean Physical Therapy Science
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• v.2 no.2
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• pp.481-486
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• 1995

Markolf and Morris suggests that the deranged disk and torn annulus have an exellent recovery ability from the position of spine extension, where the posterior annulus is not under stress and the gel can move anterioly. McKenzie explains side gliding as a combination of rotation and side bending, his clinical studies indicate that side-gliding can gel laterally. In conclusion, the prone unilateral traction on the opposite side from the patient's pain along with the other treatment appered to have helped reduce those patient's pain. The method of treatment described in this report is suggested for Korean physical therapists who treat patients suspected of posterolateral herniated nucleus pulposus.

• Industrial Engineering and Management Systems
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• v.7 no.1
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• pp.9-22
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• 2008

As an extension of a previous work by the authors (Song and Esogbue, 2006), a new algorithm for automated modeling of nonstationary seasonal time series is presented in this paper. Issues relative to the methodology for building automatically seasonal time series models and periodic time series models are addressed. This is achieved by inspecting the trend, estimating the seasonality, determining the orders of the model, and estimating the parameters. As in our previous work, the major instruments used in the model identification process are correlograms of the modeling errors while the least square method is used for parameter estimation. We provide numerical illustrations of the performance of the new algorithms with respect to building both seasonal time series and periodic time series models. Additionally, we consider forecasting and exercise the models on some sample time series problems found in the literature as well as real life problems drawn from the retail industry. In each instance, the models are built automatically avoiding the necessity of any human intervention.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.311-322
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• 2015

Objective : The purpose of this study was to investigate the effects of landing height and knee joint muscle fatigue on the movement of the lower extremity during cutting after landing. Method : Subjects included 29 adults (age: $20.83{\pm}1.56years$, height: $172.42{\pm}9.51cm$, weight: $65.07{\pm}10.18kg$). The subjects were asked to stand on their dominant lower limb on jump stands that were 30 and 40 cm in height and jump from each stand to land with the dominant lower limb on a force plate making a side step cutting move at a $45^{\circ}$ angle with the non-dominant lower limb. The fatigue level at 30% of the knee extension peak torque using an isokinetic dynamometer. Results : The results showed that the difference of landing height increased maximum range of motion and angular velocity of hip, knee, and ankle joints in the sagittal plane, and in the angular velocity of motion of the hip joint in the sagittal plane. The maximum range of motion of the knee joint in the sagittal plane and the frontal plane decreased on landing from both heights after the fatigue exercise. The angular velocity of the hip joint in the sagittal plane, and the maximum range of motion of the hip joint in the transverse plane decreased for both landing heights after the fatigue exercise. The angular velocity of the hip joint in the frontal plane decreased for the 30 cm landing height after the fatigue exercise. On the other hand, the angular velocity and maximum range of motion of the ankle joint in the sagittal plane for both landing heights, and the angular velocity and maximum range of motion of the ankle joint in the frontal plane increased on landing from the 40 cm height after the fatigue exercise. Conclusion : Different landing heights of 30 and 40 cm and 30% fatigue of peak torque of knee extensor found a forefoot and stiff landing strategy, when cutting after landing. These results might be due to decline in the shock absorption capability of the knee joint and the movement capability related to cutting while increasing the contribution of the ankle joint, which may cause increased ankle joint injuries.