• The Journal of Korean Physical Therapy
• /
• v.32 no.4
• /
• pp.210-216
• /
• 2020

Purpose: This study examined the effects of curl-up using XCO^® on trunk muscle activation in healthy adults. Methods: This study design was a single-blind randomized controlled trial. Twelve participants were enrolled in this study. The subjects were instructed to perform curl-up exercise in STCU (straight curl-up), LTCU (left twist curl-up), RTCU (right twist curl-up), TWCU (twist curl-up), and PPCU (power push curl-up). Electromyography was used to assess the percent maximal voluntary isometric contraction (%MVIC) of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) muscles. The data were analyzed using two-way ANOVA with a repeated measure. The statistical significance level was set to α=0.05 Results: The IO showed significant differences in the main effect of the group and the interactions between the group and exercise (p<0.05). In particular, the IO represented the interactions between group and exercise in the RTCU and PPCU (p<0.05). The RA, EO, and ES did not show significant interactions between the group and exercise (p>0.05). The RA, IO, and EO showed significant differences in the main effect of the group (p<0.05). The EO showed a significant difference in the main effect of exercise (p<0.05). Conclusion: These findings suggest that XCO^® can be used to increase the muscle activation of the internal oblique, which is the lumbar stabilizing muscle, when XCO^® is combined in the curl-up exercise with rotation. In the future, research on the intensity, frequency, and duration of XCO^® exercise will be needed according to the individual characteristics and preferences.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.39 no.10
• /
• pp.1053-1061
• /
• 2015

This paper discusses the analysis of the curl deformation behavior when a dynamic force is applied to a tearing tube installed on a flat die to predict the energy absorption capacity and deformation behavior. The deformation of the tips of the curling strips was obtained when the curl tips and tube body are in contact with each other, and a formula describing the energy dissipation rate caused by the deformation of the curl tips is proposed. To improve this formula, we focused on the variation of the curl radius and the reduced thickness of the tube. A formula describing the mean curl radius is proposed and verified using the curl radius measurement data of collision test specimens. These improved formulas are added to the theoretical model previously proposed by Huang et al. and verified from the collision test results of a tearing tube.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1998.03a
• /
• pp.53-57
• /
• 1998

In order to investigate the effects of the variables during the stamping process upon the side wall curl behavior, experiments and finite element analyses were done using a 90 degree draw-bending test. The variables considered were the die radius, the forming speed, the restraint force, the lubrication and the sheet grade. The experiments and simulation conditions were selected according to the design of experiment (DOE) approach. The effects of the restraint force, the lubrication and the forming speed were the same for both high strength and mild steels, but the effects of the die radius on the side wall curl were dependent on the magnitude of the die radius and the sheet grade. A straight side wall was observed for both high strength and mild steels when the die radius was about 2∼3 times of the sheet thickness. It was recommended that the restraint force, the forming speed and the friction be increased in order to reduce the side wall curl.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.475-480
• /
• 2008

Hemming, especially curl hemming, is required along the wheel housing for safety. Robot roller hemming is suitable for it. In this paper, both the flat hemming and the curl hemming along either the straight profile or the curved profile are analyzed using finite element program MSC.Marc to verify the hemming test results. Both the inner panel and the outer panel are modeled using 3-D solid elements and the roler is modeled using rigid surface. In the curl hemming, there is a case that the curl is not formed if the pre-hemming force is not sufficient. It agrees with the test results.

• International Journal of Internet, Broadcasting and Communication
• /
• v.12 no.1
• /
• pp.81-89
• /
• 2020

The purpose of this study is to investigation the effects of functional compression clothing on muscle function by comparing the iEMG response of muscle during exercise according to the wearing of taping applied functional clothing. Six men in their twenties in Chungcheongnam-do were selected for the study. Resistance exercise was performed by cross-distributing the conditions of wearing and not wearing functional clothing. Resistance exercises for iEMG measurements are biceps curl, wrist curl, reverse wrist curl, kickback and push-up. iEMG measurement muscles were the biceps brachii, triceps brachii, extensor carpi ulnaris, flexor carpi radialis. During biceps curl exercise, the iEMG of triceps brachii, biceps brachii wearing condition was lower than the non-wearing condition. During kickback exercise, the iEMG of triceps brachii, extensor carpi ulnaris wearing condition was lower than the non-wearing condition. During reverse wrist curl exercise, the iEMG of extensor carpi ulnaris wearing condition was lower than the non-wearing condition. During wrist curl exercise, the iEMG of flexsor biceps brachii, carpi radialis wearing condition was lower than the non-wearing condition. During push-up exercise, the iEMG of triceps flexsor biceps brachii, carpi radialis, brachii, biceps brachii non-wearing condition was lower than the wearing condition.

• PNF and Movement
• /
• v.21 no.3
• /
• pp.291-298
• /
• 2023

Purpose: This study aimed to suggest an effective exercise for treating anterior cruciate ligament (ACL) and hamstring injuries based on the dynamic control ratio (DCR) for the hamstring and quadriceps during eccentric hamstring exercises. Methods: Twenty-four healthy participants participated in this study. The participants performed three eccentric hamstring exercises, including the Nordic exercise, the supine leg curl, and single-leg deadlifts. During the eccentric hamstring exercises, the vastus medialis oblique (VMO), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (ST) were measured using surface electromyography. Results: The DCR was significantly lower during the supine leg curl and single-leg deadlift than during the Nordic exercise (p < 0.05). The activity of the VMO and VL was significantly greater during the supine leg curl than during the Nordic exercise and the single-leg deadlift (p < 0.05). VL activity was significantly higher during the single-leg deadlift than during the Nordic exercise (p < 0.05). ST activity was significantly higher during the supine leg curl and Nordic exercise than during the single-leg deadlift (p < 0.05). BF activity was significantly higher during the supine leg curl than during the Nordic exercise and single-leg deadlift (p < 0.05). Finally, the BF showed significantly higher activity during the Nordic exercise compared to during the single-leg deadlift (p < 0.05). Conclusion: Based on the DCR ratio and quadriceps activity, the supine leg curl should be introduced early in rehabilitation for ACL injuries.

• 한국해양학회지
• /
• v.27 no.1
• /
• pp.1-10
• /
• 1992

The sea surface winds are computed over the adjacent seas of Korea from the twice-dayily weather maps for the ten-year period 1978-1987 by using the Cardone model. Monthly mean wind-stress and wind0stress curl are also calculated and given as maps. the computed surface winds are compared with observed one at the JMA (Japan Meteorological Agency) Buoy. and the results show a good consistency in speed and direction. In particular, the magnitude of mean wind-stress is turned out to be twice bigger than the previous results over the sea of Japan. Monthly distributions of wind-stress curl reveal that over the yellow sea by the longitudinal boundary of $120^{\circ}{\;}~{\;}125^{\circ}{\;}E$, the area of negative cur exists over the western part of the sea except summer season, while the positive sign of the curl prevails over the eastern part of the Yellow Sea. However, over the Sea of Japan, with two positive maxima at the northern part and near the Wonsan Bay, the positive curl in the northern half and the negative curl in the southern of the sea characterize the monthly mean distribution of the wind-stress curl.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.1
• /
• pp.111-119
• /
• 2020

Objective: The purpose of this study is to apply exercise learning effect to various subjects through training effect and information accumulation based on verification of the effect on dumbbell curl exercises applied with virtual reality. Method: To analyze the effect on the dumbbell curl exercise in the virtual environment, a total of 20 persons with 10 males and 10 females who does not have orthopedics diseases were selected. The dumbbell weight of the subjects was set to a weight of 70% strength of 1RM. At this time, the virtual environment situation was set to four types; presence/absence of virtual environment, preferred colors, and unfavorable colors to perform dumbbell curl exercise. The anaysis of muscle activity was conducted by adhering four surface electrodes (Biceps Brachii, Triceps Brachii, Brachioradialis Muscle, Extensor Carpi Radialis Longus Muscle) on the right upper limbs. Independent sample t-test using SPSS (24.0) program was carried out to analyze average values and standard deviations for each variable depending on the presence/absence of virtual environments and changes in color (preferred colors, unfavorable colors) and the level of significance was set to a=.05. Results: In the eccentric contraction, males showed high muscle activity in the Biceps Brachii under virtual reality. On the other hand, females had high muscle activity in the Biceps Brachii in the absence of virtual reality. Also, in case of a change of colors in the virtual environment, females had the high muscle activity in the unfavorable color in the eccentric contraction. Conclusion: During the dumbbell curl exercise, results of different exercises present depending on gender. When males put VR on and performs a basic dumbbell curl exercise, the effect of Biceps presents Brachii for them while exercising in unfavorable colors. However, since it is the basic research data of muscle exercise using virtual reality, it is necessary to verify whether or not it is effective for myopachynsis through long-term training rather than unity.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.4
• /
• pp.171-181
• /
• 2020

Purpose : The purpose of this study was to investigate the effects of curl-up and proprioceptive neuromuscular facilitation (PNF) neck flexion exercises on stroke patients' trunk muscle activity, ability to control the trunk, and balance by comparing two exercise methods. Methods : The study involved patients who had been diagnosed with stroke based on the results of computerized tomography or magnetic resonance imaging at O Hospital in Daegu, South Korea, between January and July 2020. In total, 30 subjects were selected and by flipping a coin, randomly assigned to an experimental group (n=15) that performed PNF neck flexion exercises and a control group (n=15) that performed curl-up exercises. Both groups received traditional rehabilitation therapy for 30 minutes a day five times a week for a six-week period. In addition, the experimental group performed PNF neck flexion exercises and the control group curl-up exercises for 15 minutes a day five times a week over the same period. The subjects' muscle activity in the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) were measured before and after the experiment. The subjects' trunk impairment scale (TIS) and Berg balance scale (BBS) scores were also assessed. Paired t test was performed to measure the amount of statistical change before and after intervention in both groups. An independent sample T test was performed to measure the amount of statistical change between the two groups. Results : Both groups experienced statistically significant increases in their RA, IO and EO muscle activity, total TIS scores, and total BBS scores after the intervention. No statistically significant differences in the changes before and after the intervention were found for any of the resulting values between the two groups. Conclusion : A comprehensive review of the study's results suggested that neck flexion exercises using the PNF irradiation concept and curl-up exercise are effective in increasing stroke patients' abdominal muscle activity and improving trunk control ability and balance in chronic stroke patients.

• Research in Plant Disease
• /
• v.20 no.3
• /
• pp.219-222
• /
• 2014

Several tomato production regions in Korea were surveyed for tomato yellow leaf curl disease (TYLCD). Tomato leaf samples showing TYLCD-like symptoms were collected from Tongyeong (To), Geoje (Gi), and Gimhae (Gh) cities of the southern part of Korea. Tomato yellow leaf curl virus (TYLCV) was detected and the full-length genomes of the isolates were sequenced. The TYLCV isolates found in Korea shared high sequence identity (> 99%) with TYLCV-IL [JR:Omu:Ng] (AB110217). Phylogenetic relationship analysis revealed that they formed two groups (with little genetic variability), and the To, Gj, and Gh isolates belonged to the TYLCV-IL group. An infectious clone of TYLCV-To (JQ013089) was constructed and agroinoculated into Nicotiana benthamiana, Nicotiana tabacum var. Xanthi, Petunia hybrida, Capsicum annuum, and Lycopersicon esculentum cv. Hausumomotaro. Agroinfection with a dimeric infectious clone of TYLCV-To induced severe leaf curling and stunting symptoms in these plants, excluding C. annuum. Tomato plants then developed typical yellow leaf curl symptoms.