• The Research Journal of the Costume Culture
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• v.21 no.4
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• pp.606-611
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• 2013

It has been reported that tight sportswear could have complicated influence on physiological function of human body. The purpose of this present study was to investigate the effect of wearing gradient compression tights (GCT) on muscle strength and EMG activity during repeated isokinetic muscle contractions. Four healthy male undergraduate students performed maximal voluntary isokinetic concentric muscle contractions on biomechanical test and training systems with GCT and loose pants as control (Cont) respectively. During each test, the peak torque of extensor and flexor contractions and the surface electromyography (sEMG) of the rectus femoris and medial gastrocnemius was recorded simultaneously, the peak torque was recorded as an indicator of muscle strength, and the average amplitude and mean power frequency of sEMG were calculated as indicators of EMG activity. The results showed that: the peak torque decreased gradually during continuous muscle contractions both when the Cont and GCT were worn, average sEMG and mean power frequency declined along with the repetitions of muscle contractions for both wearing conditions, and the change tendency was consistence with that of peak torque. There was no obvious difference between the peak torque recorded wearing the Cont or wearing GCT, but when GCT were worn, average sEMG was lower and mean power frequency was higher than the Cont condition. In 24 samples obtained from four subjects, 80% of results showed the same trend. So we could make a conclusion that wearing GCT had no obvious effect on the improvement of muscle strength, but it would affect the EMG activity positivly.

• Journal of Advanced Technology Convergence
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• v.1 no.1
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• pp.33-42
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• 2022

The flexors and extensors of the knee joint are essential for maintaining body stability. The purpose of this study was to investigate the correlation between the isokinetic parameters of the knee flexor and extensor muscles and the function of the lower extremity muscles. Twenty-two healthy adults participated in this study. The time to peak torque (TTP), acceleration time (AT), and peak torque (PT) of the knee flexor and extensor muscles were measured. A 20m sprint, Sargent jump, one leg hop test, and side shuffle were measured to evaluate lower extremity function. The correlation between each variable was analyzed using Pearson correlation coefficient. PT of the knee flexor showed a significant correlation with single leg hops and 6M hops in a single leg. PT of knee extensors was found to be significantly correlated with Sargent jumps and triple hops. Based on the results of this study, we suggest that the strength of the knee flexor and extensor muscles has the potential to be used to predict lower extremity function.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.87-97
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• 2021

This study is to identify the effects of pilates exercise on the body composition, blood biochemical factor, isokinetic knee and trunk muscle function in menopause middle-aged women. In order to carry out this study, Twenty menopause middle-aged women were divided into two groups: pilates exercise group (PEG; n=10) and control group (CG; n=10). PEG group performed pilates exercise for 50 min per day, 2days/week for 12 weeks. As a result, first, there was an interaction effect on body fat mass in body composition. Second, there was no significant result in blood lipid and serotonin, but there was a positive trend. Third, in the isokinetic knee and trunk muscle function, the interaction effect was found in the flexor peak torque of trunk strength. The effect of the 12-week Pilates exercise on body composition, bone density, blood biochemical factor, and isokinetic muscular strength of menopause middle-aged women is partially insignificant, but the overall effect tends to be positive. In conclusion, the Pilates exercise conducted in this study is appropriate for menopause middle-aged women.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.336-345
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• 2015

This study conducted the following experiment to examine change of biophysical and physical fitness function on combined exercise program in 20' female university students with obesity according to heights of insole. Obesity related biophysical function was measured by basal metabolism and percent body fat(% Fat) and health related physical fitness was measured by isokinetic strength of quadriceps femoris muscle, muscular endurance, flexibility and power on comparative analysis of pre, post exercise and each groups(0cm, 5cm, 9cm) in 36 female university students with obesity subject according to heights of insole. These result lead us to the conclusion that each group were statistically improved at isokinetic muscular strength of quadriceps femoris muscle and basal metabolism, but 5cm group compared with 0cm and 9cm group was more significant improvement. Consequently, combination exercise applying appropriate heights of insole would be lead to positive increment of muscular strength and basal metabolism.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.17-27
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• 2020

The purpose of this study is to confirm the effects of a 6-week high-intensity combined training program on canoe athletes' cardiorespiratory function, isokinetic trunk strength, and anaerobic power. For the purpose of this study, the high-intensity combined training program was applied to 9 high-school canoe athletes. The high-intensity combined training program consists of aerobic exercise performed 2 times a week (Tuesday and Thursday), anaerobic exercise performed 3 times a week (Monday, Wednesday, and Friday), and flexibility exercise performed 5 times a week. The core of the high-intensity combined training program was the anaerobic training program performed with 100% weight for repetition; otherwise, the existing training method was divided into the percentage (%) of the 1RM. The aerobic exercise and the gym ball exercise are performed subsidiarily. Results showed that there was a statistically significant difference in height and muscle mass, whereas there was no statistically significant difference in weight, body fat percentage, and BMI followed by the high-intensity combined training program. There were statistically significant differences in maximum oxygen uptake and total exercise time. The angular velocity of 30°/sec showed a statistically significant difference in the peak torque item of flexors only. Also, the angular velocity of 120°/sec showed a statistically significant difference in the total work item of extensors only; however, there was no statistically significant difference in all the items of peak power, average power, and peak drop. In conclusion, it seems that the high-intensity combined training program may be applied as a training program for enhancing canoe athletes' performance. For further studies, more than 6 weeks training program with more participants would show improved results of isokinetic strength and anaerobic power in athlets.

• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.201-208
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• 2012

The purpose of this study was to investigate the effect of leg extension exercises performed on outdoor resistance exercise machines on knee extension muscle strength and quadriceps muscle group cross sectional area (CSA) in elderly women. Two groups were recruited for this study, including an exercise group (EG: n=13, $71.38{\pm}2.79$ yrs) and a control group (CG: n=5, $73.4{\pm}5.94$), In all subjects, maximum isometric and isokinetic muscle strength of knee flexion and extension were measured using an isokinetic dynamometer (Cybex(R) Humac Norm Testing & Rehabilitation System, USA). Quadriceps muscle group CSA were measured using MRI (Philps, Intera 1.5 T, NE Netherlands). The results of this study showed that post-intervention isometric knee extension peak torque value were higher than pre-intervention measures in the EG. However, the EG did not show improvement in quadriceps muscle group CSA, Also, no differences in the shift of optimal knee joint angle were observed between pre and post-intervention exercise. Outdoor leg extension exercise showed small increases in muscle strength in comparison to other resistance training exercises. The results of this study suggest that because outdoor leg extension exercise machines lack a progressive loading mechanism, significant increases in muscle strength may not be obtained.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.388-395
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• 2013

PURPOSE. The purpose of this study was to estimate the effects of occlusal stability to identify action mechanisms of mouthguards, known to have a modulatory effect on limb muscle function. MATERIALS AND METHODS. This study included 20 male subjects to perform the isokinetic muscle tests and the Wingate anaerobic power test on both knee joints under five closed-mouth conditions: without or with 4 types of mouthguards with thickness of 2 mm based on premolar area: (1) full-coverage, (2) anterior partial-coverage, (3) right posterior partial-coverage, and (4) left posterior partial-coverage. The obtained results were subjected to One-way ANOVA with repeated measures, followed by post hoc test of the contrast method (${\alpha}$=.05). RESULTS. There was no significant difference between the closed position with and without a full-coverage mouthguard in all variables. However, significant differences were observed between with and without a partial-coverage mouthguard in muscular endurance during extension of the left knee, muscular power and endurance during flexion of the right knee. Additionally, significant differences were found between occlusal states with full- and partial-coverage mouthguards in muscular power and endurance during extension of the left knee. CONCLUSION. These findings indicate the elevation of vertical dimension by 2 mm or the inducement of occlusal stability had little effect on isokinetic muscle strength and anaerobic performance, while uneven distribution of occlusal force might have some positive effects.

• Physical Therapy Korea
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• v.29 no.4
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• pp.262-268
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• 2022

Background: Virtual reality (VR) programs based on motion capture camera are the most convenient and cost-effective approaches for remote rehabilitation. Assessment of physical function is critical for providing optimal VR rehabilitation training; however, direct muscle strength measurement using camera-based kinematic data is impracticable. Therefore, it is necessary to develop a method to indirectly estimate the muscle strength of users from the value obtained using a motion capture camera. Objects: The purpose of this study was to determine whether the pedaling speed converted using the VR engine from the captured foot position data in the VR environment can be used as an indirect way to evaluate knee muscle strength, and to investigate the validity and reliability of a camera-based VR program. Methods: Thirty healthy adults were included in this study. Each subject performed a 15-second maximum pedaling test in the VR and built-in speedometer modes. In the VR speedometer mode, a motion capture camera was used to detect the position of the ankle joints and automatically calculate the pedaling speed. An isokinetic dynamometer was used to assess the isometric and isokinetic peak torques of knee flexion and extension. Results: The pedaling speeds in VR and built-in speedometer modes revealed a significantly high positive correlation (r = 0.922). In addition, the intra-rater reliability of the pedaling speed in the VR speedometer mode was good (ICC [intraclass correlation coefficient] = 0.685). The results of the Pearson correlation analysis revealed a significant moderate positive correlation between the pedaling speed of the VR speedometer and the peak torque of knee isokinetic flexion (r = 0.639) and extension (r = 0.598). Conclusion: This study suggests the potential benefits of measuring the maximum pedaling speed using 3D depth camera in a VR environment as an indirect assessment of muscle strength. However, technological improvements must be followed to obtain more accurate estimation of muscle strength from the VR cycling test.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.4
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• pp.147-159
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• 2008

Objectives : In order to investigate the relation of body composition analysis and isokinetic trunk muscle strength for the screening test of low back pain. Methods : This study was carried out with the data from comprehensive medical testing. 75 subject aged 20-59 performed the segmental bioelectrical impedance analysis, isokinetic trunk muscle strength test and questionnaire. Then we analyzed the relationship of data. Results : Low back pain(LBP) prevalence in high obesity index(Body mass index(BMI), Percentage of Body Fat(PBF), Waist Hip Ratio(WHR)) group was higher than LBP prevalence in normal obesity index group(p<0.001). In LBP group, Extension Peak Torque(Ext.PT), Extension Peak Torque per Body Weight(Ext.PT/BW) were significantly lower than Non-LBP group(p<0.001). And 90% of LBP group indicated abnormal Extension-Flexion Ratio(E/F ratio)(1.0 < Normal E/F ratio <1.6). When it comes to analyze relation between obesity index and muscle strength, Ext.PT/BW was significantly decreased according to PBF, WHR score. And correlation coefficient in Flex.PT, Flex.PT/BW, Ext.PT, Ext.PT/BW and PBF showed decreasing function. Conclusions : Results from this investigation showed positive correlation between obesity and LBP prevalence. Decreased muscle strength and inbalanced E/F ratio were shown in LBP. Trunk muscle strength was changed according to body mass composition parameters. This results are expected to contribute to prevent and diagnose LBP by application the clinical index of body composition analysis.

• Journal of Life Science
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• v.18 no.1
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• pp.30-37
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• 2008

The purpose of this study was to investigate the effect of Isotonic Training and Isotonic isometric complex Training to Knee joint Isokinetic muscle function in the high-school Taekwondo athlete. This subjects were randomly divided into two groups; a Isotonic Training group (n=7) Isotonic isometric complex Training group (n=7), Taekwondo athletes share each, 12 weeks between executes a motion. peak torque, H/Q ratio, bilateral muscular ratio muscular endurance of knee joint measured. For this study, two-way ANOVA with repeated measure were used. The result of this study presents between groups was not plain difference expressed. H/Q ratio, bilateral muscular ratio, muscular endurance was plain difference expressed after 12 weeks point of time (p>0.05) and peak torque was plain difference expressed (p<0.05). Conclusion each group did not appear all but one (peak torque), but point of view exercise was effect H/Q ratio, bilateral muscular ratio, muscular endurance, peak torque plain difference expressed.