• Journal of the Korean Society of Physical Medicine
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• v.7 no.2
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• pp.165-171
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• 2012

Purpose : The purpose of this study was to investigate the change of abdominal muscle activation during unilateral leg raising in supine position among three hip abduction angles($0^{\circ}$, $15^{\circ}$, $30^{\circ}$). Methods : Twenty eight able-body volunteers who had no medical history of low back and hip joint were recruited for this study. Abdominal muscle activity was recorded using surface EMG from both sides of the rectus abdominis, internal/external oblique muscle during leg raising in each position. Results : The muscle activations induced under the three different positions were compared and results showed that there was significant difference only in the right external oblique muscle activation. Conclusion : This study suggest that leg raising of different hip abduction angles without trunk control has little influence on abdominal muscle co-activation.

• PNF and Movement
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• v.15 no.2
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• pp.167-176
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• 2017

Purpose: This study investigated the effect of core and abdominal muscle-strengthening exercises on muscle activity in the lower extremity on unexpected perturbation. Methods: Twenty subjects were randomly divided into the core exercise group (n=10) or the abdominal muscles strengthening group (n=10). The two groups performed their exercises during three sessions a week for a total of four weeks. The muscle activity in the lower muscles (rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) was assessed using surface electromyography (EMG) and normalized maximal voluntary isometric contraction (MVIC) before and after the exercises. Results: An increase in the tibialis anterior activity after the core and abdominal muscles strengthening exercises was found after four weeks. A significant difference in the pre- and post-exercise was found. The gastrocnemius muscle activity increased in the core exercise group more than the abdominal muscles strengthening group. However, the difference was not significant. Conclusion: The results of this study suggest that the core and abdominal muscles strengthening exercises increased the tibialis anterior muscle activity. It is expected to help make more balance ability that affect who has abdominal muscles weakness.

• The Journal of Korean Physical Therapy
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• v.32 no.6
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• pp.394-399
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• 2020

Purpose: The aim of this study was to determine the effects of lower rib cage lateral expansion limitation on the maximal inspiratory and expiratory pressures and on abdominal muscle activity during maximal respiratory breathing in healthy subjects. Methods: Fifteen healthy male subjects voluntarily participated in this cross-sectional study. During maximal breathing, maximal inspiratory and expiratory pressures were measured, and abdominal muscle activity was determined with using surface electromyography. Also, the measurement was repeated with using a non-elastic belt to the lower rib cage for limiting of lateral expansion. A Wilcoxon signed-rank test was performed for obtaining the statistical difference with a significance level of 0.05. Results: The findings of this study are as follows: 1) There were no significant differences in maximal inspiratory and expiratory pressure with and without lower rib cage lateral expansion (p>0.05), 2) There was no significant difference in abdominal muscle activity during the maximal inspiratory phase (p>0.05). However, right external oblique muscle activity decreased significantly during maximum exhalation with lower rib expansion limitation (p<0.05). Conclusion: The results of the current study indicate that a non-elastic belt was effective in decreasing right external oblique muscle activity during forced expiratory breathing in healthy subjects.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.177-186
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• 2024

Purpose : The purpose of this study was to use oral instruction and taping to induce abdominal draw-in in the previous study, but there is a lack of research on the comparison of effects. Therefore, in this study, we would like to study how the effect of oral instruction, taping, and no feedback can affect muscle activity when performing abdominal draw-in pier exercises. Methods : Before the experiment, group A trained piers and applied only draw-in piers, group B applied taping feedback, and group C were divided into three groups per week for six weeks, and three sets of contractions for five seconds per group were performed five times, and a minute break was provided between each exercise. As a measurement tool, a wireless surface electromyography (EMG) was used to measure surface electromyography (Telemyo-DTS, NORAXON, USA) that derives a synthetic unit of muscle using a surface electrode. For statistical processing of data, the analysis is performed using the SPSS/PC Version 25.0 statistical program for Windows, and the statistical significance level is a=.05 Results : First, the duration was somewhat shorter in order to more accurately compare the muscle activity of the core muscles. Therefore, future research needs to be research that can be exercises with precise biofeedback and taping applied over a longer period of time. Secondly, it is believed that there is no significant difference, since the subjects were studied in healthy young adult men and women, not patients. Thirdly, they could not control the daily life of the subjects. Through future research, it is necessary to analyze the correlation between muscle activity and abdominal muscle thickness by adding ultrasound in addition to muscle activity in various age groups. Conclusion : During draw-in bridge exercise according to feedback, the muscle activity of the back muscle increased, and there was no significant difference in the muscle activity of the back muscle according to each feedback. Therefore, both the feedback applied during the draw-in pier exercise and the control group are effective in changing the thickness of the abdominal muscles.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.319-324
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• 2012

Purpose: This study examined the muscle activities of the erector spinae (ES) and gluteus maximus (GM) during bridging exercises with and without abdominal-hollowing. Methods: Nineteen healthy subjects with no medical history of low back pain or hip flexion contracture were enrolled in this study. The subjects performed bridging exercises with and without abdominal hollowing or with and without a one-leg lift. The muscle activities of the ES and GM were measured by surface electromyography during bridging exercises under each condition. A 2 (abdominal hollowing)X2 (one-leg lift) repeated ANOVA was used to compare the normalized muscle activities of the ES and GM. Results: The muscle activity of the ES during bridging exercise with abdominal-hollowing was significantly smaller than that without abdominal-hollowing (p=0.00). The muscle activities of the GM during bridging exercise with abdominal-hollowing were significantly greater than those without abdominal-hollowing (p=0.00). In addition, the muscle activities of the GM during bridging exercise with one-leg lifting was significantly greater than that without one-leg lifting (p=0.00). Conclusion: Bridging exercise with abdominal-hollowing appears to be more effective on activating the GM muscle than that without abdominal-hollowing minimizing the activation of the ES muscle.

• PNF and Movement
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• v.17 no.1
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• pp.137-144
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• 2019

Purpose: This study examined the effects of the abdominal drawing-in maneuver (ADIM) on muscle activity in the trunk and legs while subjects walk on a ramp. Methods: The subjects were healthy adult males (n=15) and females (n=8) in their twenties. The subjects were asked to maintain the ADIM contraction for 15 minutes using a pressure biofeedback unit. Their muscle activity was then measured while ascending or descending the ramp with or without the ADIM contraction maintained. Activity in the sternocleidomastoid, splenius capitis, rectus abdominis, external oblique abdominal, transversus abdominis, erector spinae, vastus medialis, and vastus lateralis muscles was measured using surface electromyography (TM DTS, Noraxon, USA). A paired t-test was conducted using SPSS 18.0 (IBM) for statistical data processing. Results: Maintaining the ADIM contraction during ascension led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Furthermore, maintaining the ADIM contraction during descent led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, external abdominal oblique, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Conclusion: As a result of this study, it maintains the ADIM and reduces lumbar muscle activity at the waist and increases muscle activity in the legs when walking on a ramp. Therefore, maintaining the ADIM contraction during ramp walking is recommended as training to improve the function of patients' muscular skeleton.

• Journal of International Academy of Physical Therapy Research
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• v.8 no.1
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• pp.1077-1083
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• 2017

The purpose of this study was to investigate the effects of stable and unstable bridging exercises on the EMG activity of abdominal muscles. Twenty healthy women participated in this study and the muscle activities of left-right rectus abdominis (RA), external oblique (EO), and internal oblique (IO) muscles were recorded during 4 bridging exercises (unilateral/ bilateral, stable/unstable). The activity of the right EO muscle was the highest during unilateral exercise in unstable condition, and left EO muscle also produced the same result. The activity of the right IO muscle was the highest during unilateral exercise in an unstable condition, and left IO muscle also produced the same result. The activity of the right RA muscle was the highest during unilateral exercise in a stable condition, and left RA muscle produced the same result. Unstable/unilateral (USUL) represented the highest activity among the 4 exercises. EO/IO muscles represented the highest activity during the USUL exercise, and RA did so during the stable/unilateral exercise. These results suggest that specific posture (USUL) can be administered targeting a specific side of abdominal muscles.

• The Journal of Korean Physical Therapy
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• v.32 no.2
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• pp.94-100
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• 2020

Purpose: This study examined the effects of the abdominal hollowing technique applied during plank exercises at different shoulder angles between the ground and the humerus on the abdominal muscle activity Methods: The subjects were 36 male volunteers. They were randomized to perform plank exercises or plank exercises using the hollowing technique at 80˚, 90˚, 100˚, and 110˚ between the ground and the humerus. The abdominis muscles were measured using a surface electromyogram. Independent t-tests examined the changes in the activity of these muscles according to the two exercise methods at each angle. The changes in muscle activity were examined according to the selected angles by one-way analysis of variance. Results: The activity of abdominal muscles was investigated according to the angle between the ground and the humerus during the plank exercise. As a result, the muscle activity increased significantly with decreasing angle in the rectus abdominis, external oblique, and internal oblique·transverse abdominis muscles (p<0.05). In terms of the changes in abdominal muscle activity after hollowing plank exercises at the given angles between the ground and the humerus, an increase in angle resulted in a statistically significant increase in the rectus abdominis muscle activity (p<0.05). The activities of the rectus abdominis, external oblique, and internal oblique/transverse abdominis muscles after hollowing plank exercises showed statistically significant increases (p<0.05) compared to those after plank exercises. Conclusion: The hollowing technique and the increase in the angle between the ground and the humerus may be an effective exercise method for increasing the muscle activity of the abdominis muscles.

• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.245-252
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• 2022

Objective: This study aimed to investigate the abdominal muscle activity difference while performing the abdominal bracing technique focusing on inspiration (abdominal bracing group), the general abdominal bracing technique (general bracing group), and the abdominal hollowing technique (abdominal hallowing group) Design: A cross-sectional study design. Methods: Thirty-three healthy participants were recruited for this study. The participants were allocated to 3 different groups; Abdominal bracing group, general bracing group, and abdominal hallowing group. The surface electromyography was placed over the rectus abdominis, external oblique, and internal oblique muscles to collect the activation of abdominal muscles during the trial. Results: The muscle activity of the abdominal bracing group and general bracing groups was significantly higher in all abdominal muscles than in the abdominal hollowing group (p<0.05) Both rectus abdominis and external oblique muscles showed higher muscle activations in the abdominal bracing group over the general bracing group (p<0.05). However, the ratio of bilateral external obliques and rectus abdominis to bilateral internal obliques was highest when the hollowing technique was applied (p<0.05). Conclusions: The results of study showed the abdominal bracing technique that emphasized inhalation rather than the abdominal hollowing technique or general abdominal bracing technique increased the activity of the abdominal muscles. Therefore, this study is considered to be a data for effective training if the abdominal bracing technique that emphasizes inhalation is applied as a method to increase the activation of the abdominal muscles.

• Physical Therapy Korea
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• v.21 no.1
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• pp.63-69
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• 2014

Cross knee curl-up is an ideal variation of abdominal curl up exercise to strengthen abdominal musculature without excessive lumbar flexion which can increase the loads on the disc and ligaments. In addition, slowly forced expiration can facilitate the activation of the abdominal musculature. The purpose of this study was to determine the effects of slowly forced expiration on activity of abdominal muscles, such as rectus abdominis (RA), external oblique (EO), and transverse abdominis/internal oblique (TrA/IO), while cross knee curl-up. Eleven young and healthy subjects (6 males and 5 females) participated. All subjects performed the cross knee curl-up slowly forced expiration and natural breathing. Paired t-test was performed in normalized electromyogram (EMG) muscle activity of the bilateral RA, EO, and TrA/IO to compare the differences between the cross curl-up with slowly forced expiration and natural breathing. Statistical significance was set at .05. There were no significant differences in normalized EMG muscle activity of the bilateral RA, EO, and TrA/IO between the cross curl-up with slowly forced expiration and natural breathing. The finding of this study designates that slowly forced expiration does not induce increasing activity of abdominal muscle in cross knee curl-up; hence, learning step of breathing control might not be necessary to strengthen abdominal muscle in cross knee curl-up.