• Journal of Ginseng Research
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• 제28권1호
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• pp.18-26
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• 2004

The effect of Panax ginseng administration in muscle inflammatory process induced after eccentric exercise, that causes myofibrillar disruption, was studied. Changes in lipid peroxidation, inflammation, glycogen levels in muscle and release of myocellular proteins to blood were measured. The analyses were performed immediately after eccentric exercise and over week since this period are necessary for the muscle damage-repair cycle. The ginseng extract (100 mg kg$^{-1}$ ) was orally administered to rats for three months, before the eccentric exercise performance. The results showed the protective role of ginseng against skeletal muscle damage. This effect could be associated with their membrane stabilising capacity since creatine kinase (CK) activity was significantly decreased 96 h post-exercise from 523$\pm$70 to 381$\pm$53 and 120 h post-exercise from 443$\pm$85 to 327$\pm$75 in treated animals. $\beta$-glucuronidase activity, as indicator of inflammation, showed a significant reduction of about 15-25% in soleus, vastus and triceps in these post-exercise times. The lipid peroxidation, measured by malondyaldehyde levels, was significantly decreased in the 24 h post-exercise period in soleus and vastus intermedius muscles and on the recovery period. Finally ginseng administration reduced significantly the decrease of the glycogen levels immediately after exercise and when the regenerative process took place (72-168 h post exercise). Collectively, the results have showed that ginseng did not inhibit the vital inflammatory response process associated with the muscle damage-repair cycle but presumably ameliorate the injury.

• 한국운동역학회지
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• 제22권4호
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• pp.413-419
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• 2012

The purpose of this study was to investigate the effects of increased saddle height on the length and activity pattern of vastus lateralis (VL) and biceps femoris (BF) muscle. To compare the effects of increased saddle height, Preferred (self-selected height of subject) and High saddle height (approximately 5% higher saddle height than self-selected) were used. Seven elite cyclists (career: $16.1{\pm}8.5years$) participated in 3 min. sub-maximal pedaling tests under the same cadence (90 RPM) and pedaling power (150 W). Hip and knee joint angles, and the length and activity of VL and BF were compared by measuring 3D motion and electromyography (EMG) data. Results showed that there were significant differences in peak extension timing of the hip joint angle and the range of motion of the hip and knee joint between different saddle heights. Although there were significant differences in muscle length of both muscles with increasing saddle height, the timing and amount of muscle activity differed only at the BF. These findings suggest that the timing and amount of bi-articular muscle activity (i.e. BF) can be altered by changing the saddle height. For practically applying these results, further study is necessary to evaluate the effects of various cadence and the pedaling power with various saddle heights.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.159-175
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• 2002

The effect of Panax ginseng administration in muscle inflammatory process induced after eccentric exercise, that causes myofibrillar disruption, was studied. Changes in lipid peroxidation, inflammation, glycogen levels in muscle and release of myocellular proteins to blood were measured. The analyses were performed immediately after eccentric exercise and over week since this period are necessary for the muscle damage-repair cycle. The ginseng extract $(100\;mg\;kg^{-1})$ was orally administered to rats for three months, before the eccentric exercise performance. The results showed the protective role of ginseng against skeletal muscle damage. This effect could be associated with their membrane stabilising capacity since creatine kinase (CK) activity was significantly decreased 96 h post-exercise from $523{\pm}70\;to\;381{\pm}53$ and 120 h post-exercise from $443{\pm}85\;to\;327{\pm}75$ in treated animals. ${\beta}-glucuronidase$ activity, as indicator of inflammation, showed a significant reduction of about $15-25\%$ in soleus, vastus and triceps in these post-exercise times. The lipid peroxidation, measured by malondyaldehyde levels, was significantly decreased in the 24 h postexercise period in soleus and vastus intermedius muscles and on the recovery period. Finally ginseng administration reduced significantly the decrease of the glycogen levels immediately after exercise and when the regenerative process took place (72-168 h post exercise). Collectively, the results have showed that ginseng did not inhibit the vital inflammatory response process associated with the muscle damage-repair cycle but presumably ameliorate the injury.

• Physical Therapy Rehabilitation Science
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• 제8권2호
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• pp.61-66
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• 2019

Objective: The purpose of this study was to investigate the effects of resistance applied in various directions on lower extremity muscle activity and balance during squat exercise performance. Design: Cross-sectional study. Methods: Forty-one adults (19 males and 22 females) agreed to the study purpose and procedures. All subjects randomly performed squat exercises with an intensity of overcoming 10% of body weight resistance pulled forward, backward and general squats with $60^{\circ}$ of knee joint flexion. Electromyography was used to measure muscle activity of the vastus medialis oblique (VMO), rectus femoris (RF), vastus lateralis oblique (VLO), biceps femoris (BF), and semitendinosus (ST) muscles. The Wii Balance Board was used to assess balance during the three-method squat operation. Each operation was measured three times for 10 seconds. Results: There were significant differences in muscle activities of the VMO, RF, VLO, ST and balance ability with the application of three directions of resistance (p<0.05). Post hoc comparisons revealed that squats performed with resistance pulled in the backward direction resulted in higher VMO, RF and VLO activity than with the resistance placed in a pulled forward direction (p<0.05). In the ST, resistance applied in the pulled forward direction showed greater muscle activity compared to the pulled backward direction (p<0.05). With balance, squats performed with resistance pulled in the forward direction showed greater muscle activity than with resistance applied in the pulled backward direction and during general squat performance (p<0.05). Conclusions: In this study, squat exercises performed with resistance applied in the direction of pulling backwards was found to be the most effective in improving quadriceps muscle strength and balance. It is effective to provide resistance that is placed in the forward when it is difficult to perform a general squat due to weakness of the quadriceps.

• 대한통합의학회지
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• 제9권4호
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• pp.299-309
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• 2021

Purpose : The purpose of this study was to compare the ankle pronation squat with the general squat and investigate the effect on the geun varum and the muscles around the knee. Methods : Subjects were chosen as the target for squat exercise with the distance between the knees more than 5 cm. The selected 30 students were randomly divided into 15 pronation squat group and 15 general squat group, and performed five sets movements 20 times. Global postural system (GPS) and digital goniometer were used to check the distance between the knees and the Q angle, and muscle activity was measured with EMG during squat exercise. Results: The result is as follows. First, as a result of analyzing the change in the distance between the knees, the distance between the knees decreased and the Q angle increased in the pronation squat group after exercise. Second, as a result of analyzing the change in muscle activity of the peroneus longus, the muscle activity increased in the pronation squat group after exercise, and it was more effective than the general squat group. Third, as a result of analyzing the change in the VMO (vastus medialis oblique) and VL (vastus lateralis) muscle activity ratio, the activity ratio of the pronation squat group increased after exercise, and the imbalance in the VMO/VL muscle activity was decreased. Conclusion: The pronation squat exercise applied to the ankle will greatly affect what is made into a balanced leg as decreased of the distance between knees, increased of Q angle, increased of the muscle activity of the peroneus longus and the ratio of VMO/VL.

• 한국운동역학회지
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• 제34권1호
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• pp.25-33
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• 2024

Objective: The purpose of this study was to compare the lower extremity muscle activity and knee joint load according to movement speed conditions during the barbell back squat. Method: Nine males with resistance training experience participated in this study. Participants performed the barbell back squat in three conditions (Standard, Fast, and Slow) differing movement speed. During the barbell back squat, muscle activity of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris long head (BFL), semitendinosus (ST), gluteus maximus (GM), gastrocnemius (GCN), and tibialis anterior (TA) was collected using an 8 channel wireless EMG system. The peak flexion angle of the lower extremity joints and the peak resultant joint force in each direction of the knee joint were calculated using eight motion capture cameras and ground reaction force plates. This study was to used the Friedman test and the Wilcoxon signed rank test, to compare lower extremity muscle activity and peak resultant joint force at knee joint according to movement speed conditions during the barbell back squat, and the statistical significance level was set at .01. Results: In the downward phase of the barbell back squat, the RF and TA showed the higher muscle activity in the fast condition, and in the upward phase, RF, VL, VM, BFL, ST, GM, and TA showed the higher muscle activity in the fast condition. As a results, analyzing of the load on the knee joint, in the downward phase, and in the upward phase, the higher peak compressive force of the knee joint was showed in the fast condition. Conclusion: The barbell back squat with fast movement speed was more effective due to increased muscle activity of lower extremity, but one must be careful of knee joint injuries because the load on the knee joint may increase during the barbell back squat with fast movement speed.

• The Journal of Korean Physical Therapy
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• 제17권2호
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• pp.38-45
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• 2005

This study was deigned to identify the effect of electromyographic activity of knee extensor during contralateral hip isometric adduction. six young adults who had not experienced any knee injuries were recruited. Their Q-angles were within a normal rage. They were asked to sit on the table. The EMG activities of the vastus lateralis (VL), vastus medialis oblique (VMO) were recorded in sitting by surface electrodes and normalized by MVC EMG values derived from manual muscle test. The EMG activity levels of the VL, RF, and VMO were the highest when foot was externally rotated. The EMG activity level of VMO/VL ratio did show significant differences(p<.05). The onset time of vastus lateralis (VL) and vastus medialis oblique (VMO) was similar in contralateral hip isometric adduction(p<.05).

• 한국운동역학회지
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• 제17권2호
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• pp.41-50
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• 2007

The purpose of this study was to examine the effects of Task-oriented training on the balance, lapse time and MVC(Maximum Voluntary Contraction) of CVA(cerebral vascular accident) patients. The active balance equipment was used to measure of the static balance, lapse time and task-oriented training. The EMG technique was used to record muscle activitie of affected side of gluteus medius and vastus medialis. The raw EMG data were filtered with band pass filter (60Hz) to remove artifacts and then low pass filtered (20Hz) to find the linear envelope which resemble muscle tension curve. The experiment had been conducted at the department of physical therapy in J hospital in M city during 8weeks. The thirty patients experienced the stroke were participated: training group (15), control group (15). They were ambulatory with or without an assistive device. They were assessed on central perturbation(mm) in the static balance, lapse time(s) and MVC test(mV). The data were analyzed using repeated measured ANOVA. The results were as follows: After Task-oriented training, central perturbation and lapse time was significantly differences in both groups(p<.001), and MVC in gluteus medius were no significant differences in both groups, but vastus medialis was significant differences in both groups (p<.001).

• The Journal of Korean Physical Therapy
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• 제32권5호
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• pp.273-276
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• 2020

Purpose: The purpose of this study was to investigate the effects of the resistance conditions on the electromyography (EMG) activity ratio of vastus medialis oblique (VMO) and vastus lateralis (VL) muscle during partial lunge exercise in healthy subjects in order to suggest the basic data of exercise intervention for such as patients with patellofemoral pain syndrome (PFPS). Methods: The participants of this study were healthy twenty two people with no knee pain, limitation of motion and past history of operation at lower extremity. The participants performed three types of lunge 1) no resistance, 2) anterolateral 45° resistance and 3) lateral 90° respectively. The EMG activity of the VMO and VL were recorded by surface EMG and the measured data normalized by the %MVIC value was analyzed by repeated measured ANOVA. Results: The results showed that the VMO/VL EMG activity ratio during lunge with anterolateral 45° resistance was significantly higher than with no resistance and lateral 90° resistance (p<0.05). There was no significant difference in VMO, VL, and VMO/VL muscle activity between male and female subjects (p>0.05). Conclusion: This study suggests that partial lunge exercise with anterolateral 45° resistance can increase the VMO/VL muscle activity in healthy subjects. This result could be used as basic data to develop therapeutic exercise programs such as PFPS patients.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1492-1495
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• 2008

As a prerequisite of developing muscle biofeedback system which can simulate analogous isokinetic exercise, the purpose of this study was to study the effects of frequency and amplitude of whole-body vibration on the difference in sEMG on lower extremities during leg press exercise with/without vibration. The amplitude of vibration was set to 20, 50, 80 and the frequency of vibration was set to 10, 20, 30, and 50 Hz. EMG were measured at Vastus lateralis muscle and Vastus medialis muscle. MP100 EMG module(BIOPAC system Inc., USA) was used for EMG measurement. The result showed that the combination of frequency of 30Hz and amplitude of 50 had more activated EMG than other combination with relatively small work load (30kg). It is necessary to experiment the frequency between 20 and 40Hz in detail, and to normalize sEMG using maximal voluntary contraction (MVC).