• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1554-1559
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• 2003

This study validated the musculoskeletal model of the human lower extremity by comparative study between calculated muscle parameters through simulation using modified hill-type model and measured them through isokinetic exercise. And the relationship between muscle forces and moments participated in motion was quantified from the results of simulation. For simulation of isokinetic motion, a three-dimensional anatomical knee model was constructed using trials of gait analysis and the EMG-force model was used to determine muscle activation level exciting muscles. The modified Hill-type model was used to calculate individual muscle forces and moments in dynmaic analysis and the results were validated by comparing them of experiments on BIODEX. The results showed that there was a high correlation between calculated torques from simulation and measured them from experiments for isokinetic motion(R=0.97). Therefore we concluded that the simulation by using musculoskeletal model was so useful means to predict and convalesce musculoskeletal-related diseases, and analyze unrealizable experiment such as clash condition.

• The Journal of Korean Physical Therapy
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• v.16 no.4
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• pp.1-10
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• 2004

The purpose of this study was to investigate the effects of treadmill aerobic exercise training on isokinetic muscle strength in students with cerebral palsy. The subjects consisted of 9 female students with cerebral palsy between the ages of 10 to 22. The subjects performed treadmill aerobic exercise training with $0\%$ grade by free speed with three times a week for 20 minutes a session and 12 weeks. Concentric peak torque of knee flexors and knee extensors was measured before training and after training at $30^{\circ}/sec$ and $60^{\circ}/sec$ by isokinetic dynamometer. Paired t-test was used to assess changes in variables of isokinetic muscle strength. The results of analysis are as followings. 1) After training, concentric peak torque of the least affected knee flexors(p<.01) and the most affected knee flexors (p<.01) and concentric peak torque of the least affected knee extensors(p<.01) and the most affected knee extensors(p<.01) at $30^{\circ}/sec$ significantly increased. 2) After training, concentric peak torque of the least affected knee flexors(p<.05) and the most affected knee flexors(p<.01) and concentric peak torque of the least affected knee extensors(p<.05) and the most affected knee extensors(p<.01) at $60^{\circ}/sec$ significantly increased. These findings provide evidence that treadmill aerobic exercise training improves isokinetic muscle strength in students with cerebral palsy.

• Physical Therapy Korea
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• v.1 no.1
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• pp.47-54
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• 1994

This study was designed to develop an objective method of strength measurement of muscles controlling the wrist joint in normal subjects. Forty subjects (20 male, 20 female) with a mean age of 22 years, were tested isokinetically at $60^{\circ}/sec$ and $120^{\circ}/sec$. Results were as follows, 1) Peak torque for wrist flexors, extensors were significantly different for both speeds, but wrist ulnar deviator, radial deviator peak torques were not, 2) Mean values for all muscle groups controlling the wrist were not significantly different for both speeds in the female group, 3) All mean values at both $60^{\circ}/sec$ and $120^{\circ}/sec$ were significantly different between males and females, 4) Means and standard deviations of wrist joint angle of movement at peak torque were determined.

• Physical Therapy Korea
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• v.1 no.1
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• pp.10-16
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• 1994

The purpose of this study was to establish a baseline in order that individuals may exercise safely. Sixty healthy students who were divided into two groups participated in the experiment. One group exercised both arms and legs at 60 rpm and the other at 90 rpm. There was a significant difference between arm and leg exercise in diastolic blood pressure (DBP) and time to target heart rate (tTHR). DBP decreased more in the upper (U//E) than the lower extremity (L/E), but tTHR increased more in the L/E than the U/E (p < 0.05). Systolic blood pressure (SBP) was similar for both arm and leg exercise (p > 0.05). There was also no significant difference between 60 rpm and 90 rpm in SBP, DBP or tTHR in either arm or leg exercise (p > 0.05). In conclusion, the slope of the linear increase in heart rate was steeper for U/E than L/E work. Therefore L/E exercise is safer than U/E exercise.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.2
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• pp.63-71
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• 2015

PURPOSE: The purpose of this study to investigate the effects of exercise on lumbar stabilization in muscle activity and isokinetic muscle strength of female with chronic low back pain. METHODS: The candidates was chose to twenty women in their 30s and 40s complaining back pain for over 12 weeks and consist of 10 people for lumbar stabilization and general physical therapy group(PL group), another 10 people for general physical therapy group(GP group). Lumbar stabilization exercise was conducted for 8 weeks and was comprised of 60 minutes for two times a week. In order to examine the effects of lumbar stabilization, results in the present study were analyzed maximal voluntary isometric contraction (MVIC) using electromyogram to measure muscle activity and isokinetic performance including peak torque and average power at the pre to post. RESULTS: The following are results in this study. The MVIC and isokinetic muscle strength were gradually increased in all group. As the result of the test of the MVIC and isokinetic muscle strength, the difference of lumbar stabilization and general physical therapy group is statistically more significant than that of general physical therapy group. CONCLUSION: In the present study, results indicate that lumbar stabilization helps to improve the muscle activity and isokinetic muscle strength.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.2
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• pp.37-43
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• 2021

Background: The purpose of this study is to compare and analysis the changes in strength and endurance of the knee extensor muscles after Anterior cruciate ligament reconstruction. Methods: Twelve male subjects with ligament injury were seated on Biodex and the hip joint was flexed at 110°, and torso, lower extremities, and legs were fixed using Velcro. The resistance device was placed at a point 3cm above the ankle, and measurements were taken before and a surgery at 60°/sec and 180°/sec when the knee was maximally extended. The postures ingeniously combine forward-bending poses countered with backward-bending ones. Results: There was no significant difference in the comparison of muscle strength of 60°/sec and 180°/sec before surgery. But there was a significant difference after surgery. There was significant difference in muscle endurance both before and after surgery. There was a significant difference in the pre- and post- operative comparison values of muscle strength and endurance in isokinetic movements at 60°/sec and 180°/sec during knee extension on the injured side. Conclusion: For cruciate ligament tears, Orthopedic reconstruction is recommended. Correct alignment of the knee ligament after surgery can enhance the strength and endurance of the quadriceps femoris during knee extension rejuvenated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3902-3909
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• 2009

The purpose of this study was to investigate the spontaneous therapy, TENS(transcutaneous electrical nerve stimulation) and ice therapy after induction of DOMS(delayed onset muscle soreness) through application of eccentrically exercise in ralation to biceps brachii muscle of opposite-dominance. And to explain this, we analyzed VAS(visual analogue scales), peak torque, RMS(roots mean square) when exercising elbow joint. The subjects were 30 adults without any physical defect. Subjects were divided into three groups that spontaneous therapy, TENS therapy and ice therapy after DOMS induction, choosen movement could get the maximal peak torque in angular velocity of $60^{\circ}$/sec, and mearsured peak torque, RMS and VAS. 1. The VAS was significantly decreased after 3 days application of TENS than other groups(p<.05). 2. The peak torque was significantly increased after 3 days application of TENS than other groups(p<.05). 3. The RMS was significantly increased after 3 days application of TENS than other groups(p<.05). This study showed that TENS therapy application were effective treatment strategy on DOMS than spontaneous therapy and ice therapy. Therefore, it could be considered as a treatment method in the patients with DOMS.

• Journal of the Korean Applied Science and Technology
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• v.41 no.3
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• pp.813-824
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• 2024

This study was conducted to evaluate the long-term effects of training on the physical development and exercise performance of adolescent weightlifters, aiming to provide effective training and management strategies for improving competitive performance. In order to achieve the objectives of the study, adolescent weightlifters from middle and high schools in Chungcheongnam-do province [male middle school-aged athletes, n=5; female middle school-aged athletes, n=5; male high school-aged athletes, n=12; female high school-aged athletes, n=8] were examined over approximately 10 months of weightlifting-based training to analyse the changes in body composition, physical fitness (muscular strength, muscular endurance, agility, flexibility, dynamic balance, coordination), and isokinetic muscular function (trunk and lower extremity). As a result, it was found that the physical development of middle and high school-aged athletes underwent physical development primarily characterized by an increase in lean body mass. Additionally, back muscle strength and power, which contribute to rapid and efficient force transmission between the upper and lower body, as well as grip strength necessary for controlling the barbell with a stable grip, are significant factors. These aspects were notably enhanced through specialized training and competitive experience for weightlifting performance at the high school level. On the other hand, changes in factors beyond the primary physical attributes contributing to weightlifting performance were limited, suggesting differences in effectiveness likely stemming from the specific composition of training programs or the athletes' experience and skill levels. Collectively, the findings from this study, which evaluates the physical characteristics and exercise abilities of adolescent weightlifters, are expected to contribute to improved competitive performance of weightlifters.

• Journal of Life Science
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• v.20 no.6
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• pp.870-876
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• 2010

The purpose of this study was to examine the effect of kinesio taping on muscle strength and changes of muscle fatigue and damage. 10 male subjects participated in 1-RM and isometric cybex muscle strength tests with and without taping application. Muscle strength (bench press, leg press) and extension (knee, shoulder) strength were significantly increased after taping, but there was no significant difference in flexion (knee, shoulder) strength. The concentration of fatigue factors (ammonia, phosphorous), muscle damage index substances (CK, LDH), IGF-I and creatinine were reduced after taping, but there were no significant differences.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.145-152
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• 2000

Pcak torque. angle of peak torque occurrence. total work, average power. endurance of the ankle plantar flexors were studied with the knee positioned $0^{\circ}\;and\;90^{\circ}$ flexion. Plantar flexors of 20 students were tested on Cybex 6000 dynamometer. The results were as fallows ; 1. The peak torque values were significantly higher with knee extension than knee $90^{\circ}$ flexion. 2. The angle of peak torque occurrence were earlier with knee extension than knee $90^{\circ}$ flexion, but no significant. 3. The total work were significantly higher with knee extension than knee $90^{\circ}$ flexion. at$30^{\circ}/sec$, but no significant at $90^{\circ}/sec$ 4. The endurance ratio were higher significantly with knee $90^{\circ}$ flex ion than knee extension 5. The mean average power were significantly higher with knee extension than knee $90^{\circ}$ flextion