• Journal of Korean Physical Therapy Science
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• v.1 no.1
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• pp.203-213
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• 1994

As a new concept of resistive exercise, isokinetic exercise was developed during the late 1960's. In isokinetic exercise, the subject works at a fixed speed aganist variable and totally accommodating resistance. During isokinetic exercise the resistance accommodates the external maintains maximum output throughout the full range of motion. The maximum torque during isokinetic movements is a measure of the muscular force applied in dynamic conditions.

• The Journal of Korean Physical Therapy
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• v.25 no.4
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• pp.167-173
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• 2013

Purpose: To obtain the isokinetic normative data of isokinetic laboratory of department of Rehabilitation Medicine in the normal subjects for those twenties of Korea. Methods: A total of 228 volunteers participated in this study and isokinetic evaluation of knee extensors and flexors at speed $60^{\circ}/sec$ BIODEX System 3 Isokinetic Dynamometer was performed in 128 males and 100 females. Results: In the normal subjects for those twenties, Normative data were presented. Absolute muscle strength of knee-extensors and knee-flexors, Relative muscle strength, bilateral muscle strength deficit, and flexor/extensor strength ratio were presented. Conclusion: Those results expect that it will be available for patients with 20's knee diseases to apply as the basic materials for the muscle function improvement of knee extensors and flexors.

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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• pp.201-205
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• 2023

Objective: Resistance exercise is a necessary element to improve quality of life, and measurement and evaluation of muscle strength provide important information for prescription and management of rehabilitation and exercise programs. This study analyzed the correlation between direct and indirect 1RM for isokinetic maximum torque of the knee joint in order to provide useful information in the field of exercise programs. In addition, the flexion-extension ratio and the difference in left-right deviation were verified. Design: A cross-sectional study Methods: The subjects of this study were 33 healthy adult men and women without medical problems who participated in the health exercise class program at S University in Seoul. The correlation between isokinetic maximum torque and direct and indirect 1RM was analyzed, and a dependent t-test was performed to analyze the flexion-extension ratio and left-right deviation. Results: There was a high correlation between the isokinetic maximum torque and direct and indirect 1RM, and no statistically significant difference was shown between the test methods in the analysis of the flexion-extension ratio and left-right deviation. Conclusions: Isokinetic muscle function measuring equipment is expensive, so it is difficult to use it in local exercise rehabilitation and training sites. Through this study, it was found that direct and indirect 1RM isokinetic maximum torque showed a high correlation, and there was no difference in evaluating muscle function such as flexion-extension ratio and left-right deviation. Therefore, it is considered that the muscle function evaluation using 1RM in general field can be usefully utilized.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1190-1193
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• 2004

The purpose of this study is to evaluate the possibility of identifying joint damping property through commercially available isokinetic ergometer (BIODEX). The proposed method is to estimate the damping torque of the knee joint from the difference between the external joint torque for maintaining isokinetic movement and the gravity torque of the lower leg. The damping torque was estimated at various joint angular velocities, from which the damping property would be derived. Measurement setup was composed of the BIODEX system with an external force sensor and Labview system. Matlab was used in the analysis of the damping property. The experimental result showed that the small variation in angular velocity due to acceleration and deceleration of the crank arm resulted in greater change of inertial torque than the damping torque, so that the estimation of damping property from the isokinetic movement is difficult.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.6
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• pp.82-89
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• 2010

Ankle-foot orthosis with an artificial pneumatic muscle which is intended for the assistance of plantarfelxion torque was developed. In this study, power pattern of the device in the various pneumatics and the effectiveness of the system were investigated. The pneumatic power was provided by ankle-foot orthosis controlled by user‘s physiological signal, that is, muscular stiffness in soleus muscle. This pneumatic power can assist plantarflexion torque of ankle joint. The subjects performed maximal voluntary isokinetic plantarflexion motion on a biodexdynamometer in different pneumatics, and they completed three conditions: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under muscular stiffness control. Through these experiments, we confirmed the effectiveness of the orthosis and muscular stiffness control using the analyzing isokinetic plantarflexion torque. The experimental results showed that isokinetic torques of plantarflexion motion of the ankle joints gradually increased in incremental pneumatic. The effectiveness of the orthosis was -7.26% and the effectiveness of the muscular stiffness control was 17.83% in normalized isokinetic plantarflexion torque. Subjects generated the less isokinetic torques of the ankle joints in wearing the orthosis with artificial muscles turned off, but isokinetic torques were appropriately reinforced in condition of wearing the orthosis activated under muscular stiffness control(17.83%) compared to wearing the orthosis(-7.26%). Therefore, we respect that developed powered orthosis is applied in the elderly that has weak muscular power as the rehabilitation equipment.

• 대한정형외과스포츠의학회:학술대회논문집
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• 2004.09a
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• pp.62-62
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• 2004

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.57-69
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• 1998

The role of eccentric muscle activities in functional everyday activities and sport is important and equally significant to concentric conditions. Eccentric and concentric exercise and evaluation are, therefore, very important. The purposes of this study were to measure eccentric md concentric peak torgue, percentage of peak torque, average power and percentage of average power of trunk flexors and extensors by using the Cybex NORM isokinetic dynamometer, and to standardize the value obtained. Thirty four young volunteers were tested, 17 females and 17 males, who had no history of back pain or abnormality. Each subjects were tested on three repetitions for isokinetic concentric and eccentric contraction at 5 velocities. The results were as follows; 1) Peak torque percent body weight of eccentric contraction were significantly greater than concentric contraction at each angular velocity and in trunk flexors and extensors(p<0.01). 2) Peak torque percent body weight of concentric contraction were significantly decreased as the angular velocity increased both male and female(p<0.01). 3) Peak torque percent body weight of eccentric contraction were not significantly changed as the angular velocity increased both male and female(p<0.05), 4) Peak torque percent body weight of male were significantly greater than female at each angular velocity and in concentric and eccentric contraction of trunk flexors and extensors(p<0.01)

• Journal of the Ergonomics Society of Korea
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• v.13 no.2
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• pp.49-55
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• 1994

It is not difficult to find risky manual material handling which requires various arm exertion for moving and assembling irregular stuffs in industries. Many of workers have been hurt on their muscular and skeletal system due to the manual material handling. This study is to provide data for isokinetic muscular strength elbow flexors and extensors of Korean male and female adults. Provided standard data for isokinetic muscular strength of elbow flexous and extensors can be used for scientific and systematic analysis of arm exertionl.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.1-12
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• 2003

This study was performed to provide normative isokinetic strength of knee muscles of middle school non-athletic and athletic populations for rehabilitation and pre-season screening for injury prevention. Seven non-athletic subjects and 8 hockey players participated in this investigation. Each subject was tested at speeds of $60^{\circ}/sec$, $180^{\circ}/sec$, and $300^{\circ}/sec$. The free weight of lower leg was measured at speed of $60^{\circ}/sec$ to take gravity effect Into consideration when peak torque of knee muscles occurred. The results showed that the relative peak torque production of knee flexors did not change but the relative peak torque of knee extensors decreased significantly. Mamstring/quadriceps ratios increased mainly due to significant decreases in knee extensors torque production. No significant differences were found between groups. The hamstring/quadriceps ratios for both groups were significantly lower when the gravity effect was not eliminated.

• Korean Journal of Applied Biomechanics
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• v.20 no.1
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• pp.75-81
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• 2010

Knee osteoarthritis is one of the most prevalent arthritis that weakens the muscles. This study focused on evaluating muscular functionality of knee osteoarthritis subjects. Muscular strengths of muscles around knee and hip joints of middle-aged female subjects aged over 40 suffering from knee osteoarthritis were evaluated by isokinetic dynanometer. Also, relation between the observed muscle imbalance in knee and hip joints and visual analogue scale was investigated. Subjects performed 8-weeks exercise on weakened muscles - particularly on knee extensors and hip abductors - and had their isokinetic muscular functionalities analyzed again. After the 8-weeks exercise, subjects' thigh circumferences were increased, accompanied with muscular strength improvements and decrease in visual analogue scale. Hence we emphasize the importance of exercise for muscular strength enhancement of knee extensors and hip abductors, in rehabilitation programs for knee osteoarthritis.