• The Journal of Korean Physical Therapy
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• v.19 no.5
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• pp.1-10
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• 2007

Purpose: Leg-crossing sitting is very common for men and woman. No solid evidence exists for either a beneficial or a detrimental effect of this posture. This study investigated the change of activities of trunk muscles between the normal group and the low back pain group during various leg-crossing positions. Methods: The subjects were consisted of 10 subjects who don't have low back pain and 10 subjects who have low back pain. In this study, we used electromyography(EMG) to evaluate the activities of both the trunk muscles (rectus abdominis, external oblique, internal oblique, and multifidus) during various leg-crossing positions (up-right, leg-crossing, tailor-crossing, and ankle-crossing). We analyzed the data by using repeated one way ANOVA. Results: In normal group, there were increased in EMG activities of trunk muscles, but no significant differences during leg-crossing positions. In back pain group, there were increased in EMG activities of right external oblique, left. internal oblique, and both multifidus muscles in leg-crossing and tailor-crossing position, but no significant differences during leg-crossing positions. There was no significant difference of muscle activity of trunk muscles between the back pain group and the normal group. Conclusion: We suggest that low back pain people who have weak muscles of rectus abdominis, external and internal oblique are often experienced in leg-crossing posture than normal. To compensate this unstability of trunk, leg-crossing posture is substituted passive structure for activities of active muscle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.224-230
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• 2019

The purpose of this study is to investigate the effect of the hip positions in frontal plane on abdominal muscle activities during bridging exercise. Twenty six subjects who have healthy conditions were asked to perform bridging exercise in three starting positions which are hip abduction, neutral and hip adduction. We used surface electromyography to compare the activities of both external oblique, internal oblique and rectus abdominis muscle. We analyzed the data by using repeated one way ANOVA, The alpha level was set at 0.05. The results showed that the muscle activities of both sides of external oblique, and internal oblique were significantly different among three starting positions. The activity of both sides of rectus abdominis were insignificantly different among three positions. The muscle activities of both sides of external oblique muscle and left internal oblique in bridging exercise with hip adduction position were significantly greater than hip neutral positions. The muscle activity of right internal oblique in bridging exercise with hip abduction positions. Our results suggest that bridging exercise with hip adduction position is recommended to lumbar stabilization exercise and the factor of hip position is important for controlling exercise intensity when designing bridging exercise program.

• Journal of Biomedical Engineering Research
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• v.43 no.3
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• pp.177-184
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• 2022

The purpose of this study was to present the IMU sensor based trunk stabilization exercise and to evaluate the changes in the muscle activity and thickness with non-specific low back pain patients (N=30). They were classified into two groups; lumbar stabilization exercise using IMU sensor (ILS), (n₁=20) and general lumbar stabilization exercise (GLS), (n₂=10). By comparing the difference between pre and post intervention via trunk muscle activity and muscle thickness, the significant differences were identified. Muscle activity was measured on external oblique (EO), internal oblique (IO), and multifidus (MF) by using surface electromyography (sEMG). Muslce thickness was measured on external oblique, internal oblique, transverse abdominis (TrA), and multifidus (MF) by using ultrasonography. sEMG activity was recorded at right side-bridge position. Each group performed the proposed lumbar stabilization exercise for 30 minutes a day, 5 times a week for 4 weeks. Trunk muscle activity was observed with a significant increase in the IO of ILS (p<.05) and a decrease in the MF of GLS (p<.05). Trunk muscle thickness was significantly increased in left EO and both IO of GLS (p<.05), and also significant increased right EO, both IO, both TrA, and both MF of the ILS (p<.05). In the future, a convergence approach of rehabilitation and engineering is needed to select a sensor suitable for rehabilitation purposes, study the validity and reliability of data, and produce appropriate rehabilitation contents.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.33-38
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• 2015

PURPOSE: Although the abdominal drawing-in maneuver is commonly used in clinical training for trunk stability, performing this procedure in stroke patients is difficult; instead, maximal expiration can be much easily performed in stroke patients. In the present study, we first aimed to demonstrate the effects of the abdominal drawing-in maneuver and maximal expiration on trunk stability in stroke patients. Moreover, we compared the thickness of the transverse abdominal, internal oblique, and external oblique muscles on the paretic and non-paretic sides. METHODS: We used ultrasonography to measure the change in the thickness of the transverse abdominal, internal oblique, and external oblique muscles on the paretic and non-paretic sides at rest, while performing the abdominal drawing-in maneuver, and while performing maximal expiration in 23 stroke patients. The ratio of muscle thickness between different conditions was estimated and included in the data analysis (abdominal drawing-in maneuver / at rest and, maximal expiration / at rest). RESULTS: The ratio of the thickness of the transverse abdominal, internal oblique and external oblique muscles during maximal expiration was significantly different on the paretic side (p < 0.05). The ratio of muscle thicknesses on the non-paretic side was greater during maximal expiration than during the abdominal drawing-in maneuver, although this difference was not significant (p > 0.05). CONCLUSION: Our results suggest that maximal expiration more effectively increased the abdominal muscle thickness on the paretic side. Hence, we recommend the application of maximal expiration in clinical trunk stability training on the paretic side of stroke patients.

• Physical Therapy Korea
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• v.13 no.3
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• pp.102-110
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• 2006

To improve trunk stability, various exercise protocols were introduced into the clinical field. Trunk and lumbar stability exercises on unstable surfaces are especially recommended to improve lumbar stability. The purpose of this study was to compare abdominal oblique muscle activity during leg raising in hook-lying position among 3 different type of surface conditions (on floor (F), vestibular board (VB), and foam roll (FR)). Sixteen able-bodied volunteers, who had no medical history of lower extremity or lumbar spine disease, were recruited for this study. Surface electromyography (EMG) activity was recorded from the internal and external oblique muscles of both sides. The normalized EMG activity was compared using a one-way repeated ANOVA. The results showed that the EMG activities of the internal oblique and external oblique of the lifted leg side during straight leg raising significantly increased under the FR condition when compared to the F condition. There was no significant difference of the EMG activity in abdominal oblique muscles between the VB and the FR conditions. The EMG activity of the internal oblique of supported leg side during the straight leg raising was significantly greater under the FR condition than the VB and F conditions (p<.05). The composition ratio of EMG activity of internal oblique muscles during straight leg raising was significantly increased under the FR condition. Therefore, straight leg raising exercise on foam roll in hook lying position could be beneficial to improve trunk and lumbar stability.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.71-82
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• 2023

PURPOSE: This study examined the effect of training using video content on abdominal muscle thickness, Oswestry disability index (ODI), and pain in college students with chronic back pain. METHODS: Twenty-nine college students with chronic back pain participated in this study. The subjects were assigned randomly to 15 experimental groups who trained using video content and 14 control groups who exercised voluntarily using back exercise leaflets. The video used for the intervention was obtained from YouTube, and the difficulty level of the video was classified into six levels. Both groups participated in the intervention for 40 minutes/day, three times a week for six weeks, and the variables of abdominal muscle thickness, ODI, and pain were compared before and after the intervention. RESULTS: In the experimental group, there were statistically significant changes in the thickness of the internal oblique and transverse abdominis muscles, ODI, and pain after the intervention, except for the external oblique muscle (p < .05). In the control group, there was no statistically significant difference in all variables after the intervention (p > .05). A statistically significant difference in all variables was observed between the experimental group and the control group after the intervention except for the external oblique muscle (p < .05). CONCLUSION: Treatment of chronic low back pain using video content is a possible alternative treatment if quality images are selected and the difficulty levels are adjusted.

• 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.

• The Journal of Korean Physical Therapy
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• v.29 no.2
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• pp.80-84
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• 2017

Purpose: This study was conducted to examine the effects of different sizes of blood flow restriction areas on the thickness of the external oblique and biceps brachii. Methods: The study subjects were 52 adults who were divided into four groups that performed plank exercises over a six-week period after blood flow restriction. Changes in the thickness of the external oblique and biceps brachii were measured using ultrasonography before the experiment, then three and six weeks after the experiment. The changes in each variable over time were evaluated by repeated-measures analysis of variance (ANOVA). Results: The external oblique and biceps brachii showed significant differences in muscle thickness with regard to time and the interaction between time and each group (p<0.01), but no significant differences with regards to changes between groups (p>0.05). Conclusion: A larger blood flow restriction area resulted in a statistically significant increase in muscle thickness. The results of this study may be used as the basis for future studies and for rehabilitation in clinical practice.

• Physical Therapy Rehabilitation Science
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• v.12 no.4
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• pp.398-403
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• 2023

Objective: This study compared trunk muscle activity and balance by applying hip joint flexion according to sitting posture to healthy adults Design: Cross-sectional study Methods: Twenty-four healthy adults (18 men and 6women) were instructed to perform the hip flexion while assuming two types of posture (erect sitting and slump sitting). EMG (Electromyography) data (% maximum voluntary isometric contraction) were recorded three times from the rectus abdominis, interanl oblique abdominis, external oblique abdominis and erector spine of participant's both side and the mean values were analyzed. Results: During hip flexion in erect sitting, rectus abdominis, internal oblique abdominis and external oblique muscles showed a statistically significant difference compared to hip flexion in a slump sitting position (p<0.05). In addition, the left and right deviation of hip flexion in the erect sitting position was found to be smaller than that of hip flexion in the slump sitting position. Conclusions: In this study, we compared the trunk muscle activity and balance of hip flexion in a standing sitting position and a bent sitting position. However, since only a temporary effect was verified with the cross-sectional study design, it is thought that an experimental study that can verify the long-term effect is needed in the future. Therefore, it is thought that it would be better to analyze by adding more variables than this study.

• The Journal of Korean Physical Therapy
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• v.28 no.3
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• pp.217-220
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• 2016

Purpose: This study was to investigate the differences abdominal muscles activities of according to hip adductor contraction levels 20% (mild), 50% (moderate), and 70% (strong) of MVIC on during bilateral lower extremity raising exercise on supine. Methods: The subjects of the study were a total of 39 persons including 23 healthy males and 16 females, who performed bilateral lower extremity raising exercise in 20%, 50%, 70% MVIC hip contraction. Muscle activities were measured by using S-EMG in RA (rectus abdominis), IO (internal oblique), and EO (external oblique). Results: Muscle activity of the internal oblique abdominal muscle and external oblique abdominal muscle, their activities were also greatest with the adductor contraction size at 70% and there was statistically significant difference when compared with the adductor contraction size at 20% and 50% (p<0.05). As for the rectus abdominis muscle according to the size of contraction of the adductor was greatest at 70%, without statistically significant difference (p>0.05). Conclusion: bilateral lower extremity raising with strong hip joint adductor contraction was effective exercise to strengthen abdominal muscles. If subjects could not perform strong hip adductor contraction, moderate contraction is effective abdominal muscle contraction exercise. The contraction size of the adductor is small, weak contraction may trigger middle level contraction and therefore appropriate application of the exercise program of bilateral leg raising may result in great effect as a lumbar stabilization exercise.