• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.83-90
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• 2017

Objective: To investigate the effect of short-term vibration frequencies on muscle force generation capabilities. Method: Six healthy participants were recruited for this study and only their dominant leg was tested. The subjects were tested under five conditions of vibration frequencies with constant amplitude: 0 Hz (no vibration), 30 Hz, 60 Hz, and 90 Hz, and the vibration amplitude was 10 mm for all frequency conditions. The vibration was applied to the rectus femoris (RF). The subjects were then instructed to maintain a steady-state isometric knee joint torque (100 Nm) for the first 6 s. After the steady-state torque production, the subjects were required to produce isometric knee joint torque by leg extension as hard as possible with a start signal within the next 3 s. The vibration was applied for ~4 s starting from 1 s before initiation of the change in the steady-state knee joint torque. Results: The results showed that the maximum voluntary torque (MVT) of the knee joint increased with the vibration frequencies. On average, the MVTs were 756.47 Nm for 0 Hz (no vibration) and 809.61 Nm for 90 Hz. There was a significant positive correlation (r = 0.71) between the MVTs and integrated electromyograms (iEMGs). Further, the co-contraction indices (CCIs) were computed, which represent the ratio of the iEMGs of the antagonist muscle to the iEMGs of all involved muscles. There was a significant negative correlation (r = 0.62) between the CCIs and MVTs, which was accompanied by a significant positive correlation (r = 0.69) between the iEMGs of the vibrated muscle (RF). There was no significant correlation between the MVTs and iEMGs of the antagonist muscle. Conclusion: The results of this study suggest that the short-term vibration on the muscle increases the level of muscle activation possibly owing to the increased Ia afferent activities, which enhances the muscle force generation capability.

• The Journal of the Convergence on Culture Technology
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• v.4 no.1
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• pp.33-39
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• 2018

This study was to examine the effect of self taping therapy on pain relief and improvement of daily living for older adult having knee pain. This study was conducted with a nonequivalent control group pre-test and post-test design. A total of 69 older adult in senior welfare center were recruited and were assigned to the experimental group (33) or control group (36). Self taping therapy was provided to the experimental group replace daily and apply for 7days. Data were collected before and after the intervention program. Data were analyzed using frequency, percentage, Chi-square test, and t-test with SPSS Statistics IBM 21.0 program. Knee pain(t=9.59, p<.001) and physical functions(t=7.02, p<.001) were significantly decreased in the experimental group. This study found that self taping therapy could be a useful self-management method that older adult with knee pain use easily at home.

• Journal of the Ergonomics Society of Korea
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• v.28 no.1
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• pp.9-19
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• 2009

Repetitive movement, inadequate working posture, overuse of force, physical contact with sharp edge, vibration and temperature were well known risk factors of WMSDs (Work-related Musculoskeletal Disorders). Many researchers have investigated the relationship between inadequate working postures and incidences of WMSDs of the upper extremities, whereas relatively few researchers have tried to evaluate workload associated with the lower-body postures. The effects of lower-limb postures including various knee flexion angles on the subjective discomfort, heart rate and EMG of lower-limb muscles were investigated in this study. Thirty graduate students were asked to maintain thirteen different body postures, and heart rate and EMG data of five muscle groups (electro spine, biceps femoris, vastus medialis, gastrocnemius and tibialis anterior) from each posture were collected during fifteen minutes sustaining tasks. All participants were also asked to report their discomfort ratings of body parts. Results showed that high subjective discomfort ratings and heart rates were reported at the postures of knee angles of $60^{\circ}$ and $90^{\circ}$, whereas low discomfort ratings were founded at the postures of chair heights with 20cm, 40cm, and sitting with crossed legged. The change of median frequency for each muscle group during fifteen minutes tasks was investigated for each body posture to evaluate the relationship between muscle fatigue and body posture. It was found that the trends of changes of median frequency were different based on muscle group as well as lower-limb body posture from this study.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.446-452
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• 2002

This paper Presents a 3-D design and a Vibration control of a new walking R.G.O.(Robotic Gait Orthosis) and would like to develop a simulation by this walking system. The vibration control and evaluation of the new knee joint mechanism on the biped walking R.G.O.(Robotic Gait Orthosis) was a very unique system and was to obtain by the 3-axis accelerometer with a low frequency vibration for the paraplegia It will be expect that the spinal cord injury patients are able to recover effectively by a biped walking R.G.O.. The new knee joint system of both legs were adopted with a good kinematic characteristics. It was designed attached a DC-srevo motor and controller, with a human wear type. It was able to accomodate itself to a environments of S.C.I. Patients. It will be expect that the spinal cord injury patients are able to recover effectively by a new walking R.G.O. system.

• Korea Journal of Hospital Management
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• v.23 no.3
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• pp.52-62
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• 2018

This study aims to analyze the factors affecting in-hospital complication and length of stay in elderly patients with total knee arthroplasty. A total of 8,224 inpatients over 65 years old were selected from the national old inpatient sample data which was produced by Health Insurance Review and Assessment Service in 2016. STATA 12.0 was performed using frequency, chi-square test, t-test, ANOVA and multiple linear and logistic regression analysis. Analysis results show that ages(over 85), Charlson Comorbidity Index, district(metropolitan) for general hospitals and gender, district, beds(100-199) for hospitals are significantly influenced in-hospital complication. Statistically significant factors affecting the length of stay are gender, insurance type, depression, district, bed(300 over) for general hospitals and gender, type of insurance, Charlson Comorbidity Index, depression, district, beds(200-299) for hospitals. Based on these findings, the factors affecting in-hospital complication and length of stay were different depending on the type of medical institution. Accordingly, policymakers should analyze the differences in care behavior depending on the type of medical institution and expand policy and financial support to resolve them.

• Korean Journal of Adult Nursing
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• v.24 no.3
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• pp.253-265
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• 2012

Purpose: The focus of this research was a systematic review of published articles and theses for a degree in Korea and foreign countries on rehabilitation therapy for patients with total knee arthroplasty (TKA). Methods: The literature until December in 2011 were searched and the data basis included Medline, CINAHL, KERIS, National Library of Korea, and National Assembly Library web sites. Words for the search were TKA or TKA and rehabilitation. Studies included randomized controlled and non-equivalent control group pretest-posttest design. 31 studies were analyzed focusing on type, application method, dependant variable and effect using descriptive statistics. Results: Seventeen rehabilitation therapies and forty-nine dependant variables were used. The application methods of rehabilitation therapy were diverse. The most frequently used rehabilitation type was an exercise therapy and a pain/discomfort was the most frequently used dependant variable. The effects of rehabilitation therapy were inconsistent. Conclusion: The individualized rehabilitation therapy must be comprised of type, time, frequency, period and duration. Attention must be made as to the research design, especially the better measurement of the dependent variables. This review may serve as a base for future research.

• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.175-182
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• 2010

The purpose of this study was to evaluate the biomechanical effect of sports taping on the lower limb during drop landing. Twelve male university students who have no musculoskeletal disorder were recruited as the subjects. Principal strain, median frequency, vertical GRF, loading rate, angular velocity and resultant joint moment were determined for each trial. For each dependent variable, paired t-test was performed to test if significant difference existed between taped and untaped conditions(p<.05). The results showed that principal strain of the thigh and the shank in taping group were significantly less than those found in control group. These indicated that sports taping may prevent excessive mechanical strain caused by impact force during the deceleration phase. Flexion(-)-extension(+) and varus(-)-valgus(+) resultant joint moment of the knee joint in taping group were greater than corresponding value for control group. It seems that extensor muscle of the knee joint were not only supported by sports taping during knee flexion but also sports taping is effective for minimizing the possibility of injury.

• YAKHAK HOEJI
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• v.52 no.2
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• pp.101-110
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• 2008

Total Knee Replacement (TKR) surgery is one of the invasive procedures for patients with late-stage knee joint disorders. In the present study, economic efficiency was compared between uses of the 2nd and 3rd generation cephalosporins for the prophylaxis before and after the surgery using frequency analysis in terms of various factors such as medication costs, the number of days of antibiotic use and hospitalization due to TKR surgery. The results showed that the 3rd generation cephalosporins did not reduce the infection rate and total medication costs, but rather raised antibiotic cost in comparison with the 2nd ones. A frequent use of the 3rd ones is closely related to emergence of resistant bacterial strains. Therefore, we suggest that unnecessary prescriptions for the broad spectrum antibiotics should be avoided.

• Journal of Biomedical Engineering Research
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• v.26 no.2
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• pp.111-116
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• 2005

This study was designed to apply the stimulation system developed in our laboratory to investigate how the stimulation conditions affect the muscle contractile characteristics in the isometric condition as well as during the FES standing/walking. Four paraplegic and ten healthy subjects participated in this study, and their knee extensors were voluntary contracted or electrically stimulated to measure the muscle force and the fatigue index for different waveforms of the pulse train. We also investigated different combinations of the electrode positions during standing/walking. It was confirmed that continuous and high-frequency stimulation causes faster fatigue than intermittent and low-frequency stimulation. Fatigue resistance was higher around the optimal muscle length than at a stretched position in healthy subjects, whereas the opposite was observed in paralyzed subjects. The paired t-test results with the level of significance at 0.01 indicated that the sinusoidal waveform generated the largest torque among the four typical waveforms. Although statistically not very significant, the sinusoidal waveform also generated, in general, the highest fatigue resistance at an intensity level below the supramaximal stimulation. One of the paraplegic subject who participated in the standing/walking program can now stand up for 1 minute and 50 seconds with the knee extensors, and walk for about 5 minutes at the speed of 12m/sec.

• Korean Journal of Applied Biomechanics
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• v.28 no.3
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• pp.159-164
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• 2018

Objective: The aims of this study were to determine the impact peak force and kinematic variables in running speed and investigate the relationship between them. Method: Thirty-nine male heel strike runners ($mean\;age=21.7{\pm}1.6y$, $mean\;mass=72.5{\pm}8.7kg$, $mean\;height=176.6{\pm}6.1cm$) were recruited in this investigation. The impact peak forces during treadmill running were assessed, and the kinematic variables were computed using three-dimensional data collected using eight infrared cameras (Oqus 300, Qualisys, Sweden). One-way analysis of variance ANOVAwas used to investigate the influence of the running speed on the parameters, and Pearson's partial correlation was used to investigate the relationship between the impact peak force and kinematic variables. Results: The running speed affected the impact peak force, stride length, stride frequency, and kinematic variables during the stride phase and the foot angle at heel contact; however, it did not affect the ankle and knee joint angles in the sagittal plane at heel contact. No significant correlation was noted between the impact peak force and kinematic variables in constantrunning speed. Conclusion: Increasing ankle and knee joint angles at heel contact may not be related to the mechanism behind reducing the impact peak force during treadmill running at constant speed.