• The Korean Journal of Emergency Medical Services
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• v.9 no.2
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• pp.129-136
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• 2005

The purpose of this study was to compare the level of physical fitness and isokinetic strength, between EMT student and physical education students. Nine a major in EMT student volunteers, and nine a major in physical education student volunteers participated in that study as subjects. The basic physical body composition, fitness and isokinetic strength were measured. The data obtained in the study was analyzed by SPSS PC+ for window version 10.0. The difference in the mean of each variable between the two groups was analyzed by using the independent t-test and the significance level for all analysis was set at <.05. The results were as follows ; 1. There was a significant difference in the basic physical fitness between the two groups with the exception flexibility. The difference showed the statistical significance on back strength, balance and power in physical education students. 2. There were significant difference in body composition between the two groups with the exception of lean body fat. The difference showed the statistical significance on body fat%, body fat mass in the physical education students. 3. There was significant defference in the isokinetic strength between the two group. The difference showed the statistical significance on peak torque, peak torque B/W%. It was concluded that the physical education students may not have an effect of flexibility; however, back strength, balance, power, body composition, isokinetic strength, could be enhanced due to the long-term period of training. Based on the findings of this study, the regular participation of regular exercise help the untrained men achieve health-related fitness.

• Polymer(Korea)
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• v.24 no.1
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• pp.105-112
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• 2000

Using a commercial epoxy/carbon fiber composite prepreg (DMS 2224) as a model system, the cure kinetics of vitrifying thermoset system were analyzed by isothermal and dynamic-heating experiments. Focusing on the processing condition of high performance composite systems, a phenomenological kinetic model was developed by using differential scanning calorimetry (DSC) and reaction kinetics theories. The model system exhibited a limited degree of cure as a function of isothermal temperature seemingly due to the diffusion-controlled reaction rates. The diffusion-controlled cure reaction was incorporated in the development of the kinetic model, and the model parameters were determined from isothermal experiments. The first order reaction was confirmed from the characteristic shape of isothermal cure thermograms, and the activation energy wes 78.43 kJ/mol. Finally, the proposed model was used to predict a complex autoclave thermal condition, which was composed of several isothermal and dynamic-heating stages.

• Journal of Korean Physical Therapy Science
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• v.13 no.2
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• pp.7-16
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• 2006

The purpose of this study was to investigerate the changes of isokinetic muscular function in elderly people who have been to take from osteoarthritis in both knee joints after 36 weeks' rehabilitative therapy programs. In this study the subjects were 20 women residing in S-Tower(n=10) and H-welfare Town(n=10) respectively. The rehabilitative group(equal to experimental group) had taken part in exercise program 5 days per week. And then was performed by warm up, workout(involving aerobic exercise and weight training), cool down, physical therapy(cryotherapy, TENS, ultrasound). Also its programs were classified in conditioning phase($0{\sim}12$ weeks), improvement phase($13{\sim}24$ weeks), and maintenance phase($25{\sim}36$ weeks) respectively. The results of inspections were as followed: In the isokinetic muscular function, there were significant differences in right leg's flexor and extensor in $60^{\circ}$/sec. And there were significant differences in right leg's flexor and left leg's extensor in $180^{\circ}$/sec. At last, there were significant differences in right leg's flexor and left leg's extensor in $240^{\circ}$/sec. In other words, the rehabilitative programs for 36 weeks could increase the muscular function in elderly with OA. In conclusion, the rehabilitative programs of this paper has shown the positive results, which involved in the muscular function variables in elderly people with OA in both knee.

• Physical Therapy Korea
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• v.16 no.1
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• pp.25-33
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• 2009

In dancers, intact muscular coordination is a well balanced antagonist, which could be a decisive factor in protection against injury as dancers often have hypermobile joints and their ankle joints often bear their full body weight in extreme positions. The purposes of this study were to identify the isokinetic strength to the knee and ankle and the isometric strength of the trunk in female collegiate dancers and controls. Furthermore, the study aimed to investigate the peak torque ratio of knee extension to flexion, ankle plantarflexion (PF) to dorsiflexion (DF), and dominant legs to nondominant. Twenty-one female collegiate dancers (20.0 years of age) and twenty-one female collegiate students (19.3 years of age) performed isokinetic maximum efforts of the knee extensors and flexors at $60^{\circ}/sec$ and $120^{\circ}/sec$, the ankle plantarflexors and dorsiflexors at $30^{\circ}/sec$ and $120^{\circ}/sec$ and isometric maximum efforts of the lumbar extensors at $0^{\circ}$, $12^{\circ}$, $24^{\circ}$, $36^{\circ}$, $48^{\circ}$, $60^{\circ}$, and $72^{\circ}$. The results were as follows: The isokinetic peak torque of the knee extensors and the ratio of knee extensors to flexors of dancers were significantly higher than those of controls (p<.01). However, the isometric peak torque of the back extensors (p<.01) and isokinetic peak torque of the ankle plantarflexors and dorsiflexors (p<.05) of dancers were significantly lower than those of controls. Further studies are needed to identify the difference in proprioception of the joints between dancers and controls.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.3
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• pp.91-98
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• 2008

Objectives : The purpose of this study is to evaluate flexor-extensor muscle strength of trunk according to Sasang constitution. Methods : This study was carried out with the data from comprehensive medical testing. People were performed Trunk Extension Flexion(TEF) Program of CYBEX NORM System and QSCC(Questionnaire of Sasang Constitution Classification) II test. And then we made three groups according to Sasang constitution and analyzed isokinetic strength on the TEF. Results : 1. A significant difference(Taeumin>Soeumin>Soyangin) was found in flexor muscle peak torque(PT) of trunk according to Sasang constitution(P<0.05). 2. A significant difference was not found in flexor muscle peak torque%body weight (PT%BW) of trunk according to Sasang constitution. 3. A significant difference(Taeumin>Soeumin>Soyangin) was found in extensor muscle peak torque(PT) of trunk according to Sasang constitution(P<0.05). 4. A significant difference(Soeumin>Taeumin>Soyangin) was found in extensor muscle peak torque%body weight(PT%BW) of trunk according to Sasang constitution(P<0.05). Conclusions : There is a significant difference in isokinetic strength on the TEF according to Sasang constitution.

• Physical Therapy Korea
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• v.14 no.3
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• pp.41-47
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• 2007

Dance movements consist of combinations of movements such as jumping, rotation, maintaining balance, leg lifts, and plantar flexion with toe shoes. Dance movements require great muscle strength of lower extremities as well as muscular endurance. The purposes of this study were to investigate correlation between the anthropometric variables and the peak torque in young female dancers and to identify variables that affect isokinetic peak torque. Twenty-six female dancers ($19.7{\pm}1.2$ years of age) performed concentric maximum force efforts on the knee extensors and flexors at $60^{\circ}/sec$ and $120^{\circ}/sec$, the ankle plantar flexors (PF) and dorsiflexors (DF) at $30^{\circ}/sec$ and $120^{\circ}/sec$. Antropometric variables such as age, height, weight, body mass index (BMI), thigh girth, calf girth and duration of dance training were measured. To identify antropometric variables related to muscle strength, Pearson correlations were computed and a stepwise multiple regression analysis was performed. Pearson correlation coefficients of Knee extensor at $60^{\circ}/sec$ and $120^{\circ}/sec$ revealed moderate positive associations with BMI and thigh girth. Pearson correlation coefficients of ankle PF revealed low-to-moderate positive associations with height. Ankle DF also revealed moderate positive associations with BMI and calf girth. The main predictor variables of knee extensor at 60/sec, were stepwise multiple regression, age, height, thigh and girth.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.75-90
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• 1991

This study is to characterize the effects of swimming exercise on the composition of muscle fibers in rats lower limb tissue. By comparing the exercised group (4, 8 weeks) with the control group, we analyzed the difference histologically, histochemically and morphometrically. The obtained results are as follows ; 1. In the histological view, the distance between the individual muscle fibers and the muscle bundles in exercised group was shorter than that of control group. The irregular shape of sarcolemma in exercised group was observed. 2, In the histochemical view(NADH-TR. and Myosin ATPase reaction analysis), the increased populations of red and intermediate fibers were observed, whereas the white fiber was decreased. 3. In the morphometrical view, the red and intermediate fibers of tibialis anterior and gastrocnemius in exercised group were quantitatively increased, compared with control group. However, the white fiber and connective tissue in exercised group were decreased.

• The Journal of Korean Physical Therapy
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• v.23 no.1
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• pp.13-19
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• 2011

Purpose:This study was designed to investigate difference in isokinetic muscle strength in the knee extensor muscle and characteristic differences in muscle strength between males and females through the ankle joint angles. Methods: Seventy-four subjects participated in this study. There were two groups: 36 males and 38 females. The mean age of the men was 24.58 years and women was 23.74 years. Subjects were seated on a CON-TREX LP (leg press) lean to back of chair, and there bodies were fixed by straps with the hip joint at an angle of $130^{\circ}$. After randomly fixing the ankle joint at $0^{\circ}$, $20^{\circ}$, and $40^{\circ}$ of plantar flexion (PF) in range of full extension of knee joint. We studied force max average, force max average/kg, power average, and total work through the angle of the ankle joint when the knee joint was extended from $90^{\circ}$ to $180^{\circ}$. Results: In the male group, all maximum measured value showed at the ankle joint $0^{\circ}$, all minimum measured value showed at $40^{\circ}$ PF (p<0.01). In the female group, all maximum measured value showed at the ankle joint $20^{\circ}$ PF, especially the power average increased significantly. All minimum measured value showed $40^{\circ}$ PF (p<0.01). Conclusion: There are differences between males and females in isokinetic muscle strength of the knee extensor through ankle joint angles in healthy adults. Males and Females have different characteristics of muscle strength through the ankle joint angles.

• Archives of Orthopedic and Sports Physical Therapy
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• v.14 no.2
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• pp.45-53
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• 2018

Purpose: The purpose of this study was to investigate the effects of muscle activity and muscle strength according to verbal command volume during isokinetic and isometric quadricep exercises. Methods: To measure muscle activity and muscle strength, surface electrodes were attached to the participants, as they sat on a Biodex chair. The isometric exercise was performed three times, with maximum exercise at $30^{\circ}$ bending angle, based on a maximum extension state of the knee at $0^{\circ}$. The average holding time was unified to three seconds. In addition, the isokinetic exercise was performed three times, at $60^{\circ}/sec$. The verbal command ranged between 0∾60 dB and 0∾75 dB. Muscle activity was measured using surface electromyography (4D-MT, Relive, Gimhae, Korea). The Biodex System 4 was used to measure the isometric and isokinetic strength of the nodal line, and 4D-MT was used to measure muscle activity. Results: There were significant improvements in the maximal and relative muscle strengths, when the 0∾ 60 dB and 0∾75 dB verbal commands were applied with isokinetic extension/flexion (p<.05). The isokinetic exercise (0∾75 dB) group showed a significant difference in the vastus medialis oblique muscle activity change (p<.05), while the isometric exercise (0∾75 dB) group showed a significant difference in the rectus femoris muscle activity change (p<.05). Conclusions: Our results reveal that verbal commands effectively improve muscle activity and muscle strength during isokinetic and isometric quadricep exercises.

• Korean Journal of Applied Biomechanics
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• v.32 no.3
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• pp.103-110
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• 2022

Objective: The aim of this study was to investigate effect of core stabilization exercises on the erector spinae contractile properties and trunk isokinetic muscle function of middle age with low physical activity and sedentary lifestyle. Method: Twenty (female: n=10, male: n=10) middle-age subjects (age: 37.25 ± 6.08 years, height: 168.01 ± 6.84 cm, weight: 71.37 ± 11.75 kg) participated in this study. Tensiomyography was measured on the erector spinae, and the isokinetic trunk muscle function test was measured at an angular velocity of 60 °/s and 90 °/s. All subjects performed the core stabilization exercises for 60 min per day, 3 times a week, for 7 weeks. A paired t-test was performed with a significance level of 0.05. Results: Tensiomyography of the erector spinae revealed a significant post-exercise increase in the maximum radial displacement (p < .05) and velocity of contraction (p < .05), however, there wasn't a significant post-exercise change in the contraction time. Additionally, the isokinetic muscle function test of the trunk revealed a significant post-exercise increase in trunk extensor relative strength (p < .05) and strength ratio (p < .05). Conclusion: Our results indicated that core stabilization exercises reduced erector spinae muscle stiffness, increased the velocity of erector spinae contraction. Additionally, data showed the improvement in the trunk extensor strength help induce a more balanced development in trunk muscle.