• PNF and Movement
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• v.17 no.3
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• pp.401-409
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• 2019

Purpose: This study investigated the muscular activity of abdominal muscles during a variety of plank exercises following changes in the leg and head positions. Methods: Thirty healthy individuals participated in this study. They performed six variations of plank exercises, including three changes in head position and two changes in leg position. Each plank was defined as head neutral-leg neutral, head up-leg neutral, head down-leg neutral, head neutral-leg wide, head up-leg wide, and head down-leg wide. During the plank excises, the muscle activities of the rectus abdominis, internal oblique, erector spinae, and upper trapezius were measured. Results: The head down position significantly increased the rectus abdominis activity compared to other head positions (p<0.05). On the other hand, the upper trapezius muscle activity was significantly higher with the head up position compared to other head positions (p<0.05). Regardless of head positions, both the rectus abdominis and internal oblique muscles were significantly activated with leg wide position compared to the leg neutral position (p<0.05). Conclusion: Head and leg positions could change the muscular activities of abdominal muscles during plank exercises. For example, the head down position is effective for activating the rectus abdominis while the leg wide position could be advantageous for enhancing the internal oblique and rectus abdominis.

• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.41-48
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• 2023

Background: This study examined the effects of the bridge exercise with trunk rotation on the thickness of body trunk muscles, including external oblique, internal oblique, and transverse abdominis in healthy male adults. Design: Randomized controlled trial Methods: Twenty-four men were evenly divided into a trunk rotation bridge exercise group and a basic bridge exercise group by drawing lots. The two groups performed the respective exercise for thirty minutes, three times a week for six weeks. repeated measure analysis of variance (ANOVA) was used after distinguishing between three different time points before the experiment, three weeks after the experiment, and six weeks after the experiment. The significance level was set at 0.05. In case an interaction between time and group existed, the paired t-test was used to examine the within-group difference. The independent-sample t-test was used to check the between-group difference. The significance level was set at 0.05. Results: All the men showed a significant change over time in their external oblique, internal oblique, and transverse abdominis muscles. An interaction between time and group was also found (p<0.05). Conclusion: The bridge exercise with trunk rotation causes a meaningful difference in the thickness of external oblique, internal oblique, and transverse abdominis muscles. Therefore, this study proposes the use of this exercise for lower-back stabilization in future research and clinical settings.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.3
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• pp.207-214
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• 2017

The problem of trunk stability is a major factor in back pain.. Abdominal draw in maneuver(ADIM), One of the trunk stabilization exercises to relieve lumbar instability, is a method of inducing selective contraction of the transverse abdominis associated with anticipatory posture control among the abdominal stabilization muscles. ADIM is usually performed with a visual feedback by applying a pressure biofeedback unit(PBU) under the lumbar at the supine position, which is not functional compared to the sitting position. This study was conducted to investigate the effect of ADIM applied in supine and sitting position on 31 healthy men and women. In each posture, muscle activity was measured by rectal abdominis (RA), external oblique (EO), transverse abdominis (TrA)/internal obilique (IO) and erector spinae (ES) using wireless EMG. In the result, there was no significant difference between RA and EO between the two postures and there was a significant difference between TrA / IO and ES. In both postures, the activity of TrA/IO was higher than that of RA, and the effect of ADIM was shown to be the same, whereas TrA/IO and ES showed higher activity in sitting position. This means that the activity of the muscles involved in the postural stability and lumbar stability is increased further in the sitting position. Therefore, ADIM in sitting, which can be applied more easily in daily life, is useful for improving lumbar stability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.11
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• pp.2321-2326
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• 2011

Cervical vertebrae are a complex structure and an important part of human body connecting the head and the trunk. In this paper, we propose a method to extract sternocleidomastoid muscle from ultrasonography images of cervical vertabrae automatically. In our method, Region of Interests(ROI) is extracted first from an ultrasonography image after removing unnecessary auxiliary information such as metrics. Then we apply Ends-in search stretching algorithm in order to enhance the contrast of brightness. Average binarization is then applied to those pixels which its brightness is sufficiently large. The noise part is removed by image processing algorithms. After extracting fascia encloses sternocleidomastoid muscle, target muscle object is extracted using the location information of fascia according to the number of objects in the fascia. When only one object is to be extracted, we search downward first to extract the target muscle area and then search from right to left to extract the area and merge them. If there are two target objects, we extract first from the upper-bound of higher object to the lower-bound of lower object and then remove the fascia of the target object area. Smearing technique is used to restore possible loss of the fat area in the process. The thickness of sternocleidomastoid muscle is then calculated as the maximum thickness of those extracted objects. In this experiment with 30 real world ultrasonography images, the proposed method verified its efficacy and accuracy by health professionals.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.1
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• pp.44-51
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• 2007

The purpose of this study was to identify the relationship between the cumulative fatigue of trunk muscles andthe period of recovery time during repetitive lifting and lowering tasks with symmetric and asymmetric postures.Ten subjects participated in the experiment. Subjects had 1, 2, 3, 4 and 5 minutes recovery time respectivelywhile they were performing the lifting and lowering task repeatedly for 3 minutes with the weight equivalent to25% level of MVC. EMG signals from ten trunk muscles were collected and the fatigue level was analyzedquantitatively. In results, the local muscle fatigue was no longer accumulated when 5 minutes recovery time wasgiven in symmetric position. For asymmetric position, it took longer minutes to prevent the fatigue accumul-ation. Different trunk muscles indicated slightly different recovery patterns in terms of MPF (Mean Powerfrequency) value.This result would help ergonomist design the length of recovery time to control the cumulative fatigue of trunkmuscles in industry with repetitive lifting and lowering task.

• Journal of the Ergonomics Society of Korea
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• v.22 no.4
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• pp.47-57
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• 2003

This study investigated the recruitment patterns of ten trunk muscles in isometric exertion tasks, focused on the functional roles (agonist or antagonist). Twelve male students performed maximum voluntary isometric exertion tasks towards six directions: flexion/extension, left/right lateral bending, and clockwise/counter-clockwise twisting. EMG signals from ten trunk muscles and exertion forces were collected. Normalized EMG (NEMG) values were calculated at 10, 20, 30, 40, 50, 60, 70, 80, and 90 %MVC. The subjects showed a limited capacity in producing twisting moments, approximately 50% of the extension moment, and 70% of lateral bending moments. EMG activity was dependent on the direction and magnitude of the exertion, and also on the functional role. The mean NEMG of agonist was 0.260 and 0.067 for antagonist. Agonists showed the highest mean NEMG in flexion (0.367), while antagonists showed the highest mean NEMG in twisting clockwise/counter-clockwise (0.090/0.106).

• Journal of Biomedical Engineering Research
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• v.21 no.2
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• pp.219-224
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• 2000

본 연구는 몸통의 반복적인 flexion/extension 동작 수행시 근전도신호를 측정하고 이들 신호에서 나타난 EMG parameters(median frequency, median power, RMS) 와 피실험자의 주관적 불편도의 변화양상간의 정량적인 관계를 알아보고자 수행되었다. 피실험자별로 3-5회 정해진 업무를 수행하였고 주관적불편도와 근전도 신호를 측정하였다. 실험결과 반복횟수가 증가할수록 주관적 불편도는 증가하였으며 각 task 별로 EMG parameter와 불편도의 증감율 간의 회귀분석과 상관분석을 수행한 결과 실험과 EMG parameter에 따른 변이는 존재했지만 대체로 RMS에 비해 MF와 MP의 증감율이 불편도 증감율과 상관관계가 높은 것으로 나타났다.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.2
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• pp.25-31
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• 2016

PURPOSE: The purpose of this study was to compare the trunk muscle activity according to the direction of upper extremity lifting using elastic band. METHODS: Thirty three healthy individuals participated in this study. Each subject performed upper extremity lifting using elastic band on two different directions (straight and diagonal). And then we compared the muscle activity of respective trunk muscles of both directions. In order to examine the muscle activity of trunk muscle, we used the electromyogram to measure peak and mean torque in shoulder 90 degree flexion with sitting position. Electromyographic activities were recorded from the external oblique, internal oblique, rectus abdominis, and erector spine muscles during upper extremity lifting. RESULTS: As a result, first, there was significant difference between two directions. The muscle activity of ipsilateral external oblique and contralateral internal oblique is significantly increased in both straight and diagonal directions (p<0.05). Second, the muscle activities of external oblique and internal oblique of both side showed significant difference in diagonal direction (p<0.05). Third, the muscle activity of erector spine of both side showed significant difference in straight direction (p<0.05). CONCLUSION: Through this study, it is important that implement diagonal direction exercise at sitting positions to help increasing muscle activity of ipsilateral external oblique and contralateral internal oblique on patients when activating the trunk muscle or stabilizing the trunk.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.2
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• pp.73-80
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• 2015

PURPOSE: The purpose of this study is to compare ultrasound images of trunk muscles according to gender in healthy subjects. METHODS: Twenty six subjects(13 males and 13 females) were enrolled in this study. The thickness of trunk muscles was measured for transverse abdominis (TrA), external oblique abdominis (EOA), internal oblique abdominis (IOA), and multifidus (MF) using ultrasound. The thickness of the muscles was measured for the length of cross-section except for fascia. The muscle thickness wasmeasured at the both side, then the mean value was calculated. Also, each of trunk muscle wasanalysed by echodensity, white area index. RESULTS: As a results, there was significant difference in muscle thickness of EOA, IOA according to gender (p<0.05). The male was significant increase than female of EOA, IOA in muscle thickness. There was significant difference in echo intensity of TrA, MF according to gender(p<0.05). The female was significant increase than male of TrA, MF in echo intensity. There was significant difference in white area index of EOA according to gender(p<0.05). The female was significant increase than male of EOA in white area index. CONCLUSION: The findings of this study suggest that healthy male have a greater EOA, IOA trunk muscle thickness than female. However, the difference of muscle quality between male and female was showed through thisexperiment. Therefore, the ultrasonography images will be useful tool for seeing quantitative and qualitative difference of trunk muscles according to gender.

• Journal of agricultural medicine and community health
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• v.43 no.4
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• pp.250-257
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• 2018

Objecctives: This study investigates the effects of using customized walking aids individualized for stroke patients by measuring the effects of different cane lengths to determine the ideal length of walking aids for stroke patients. Methods: Cane lengths were determined from the greater trochanter with walking aids measured 5cm below, at the greater trochanter and 5cm above. All patients walked for ten meters with each cane length to measure speed. Then, we measured the opto gait, timed up go test, and electromyography three times each. Statistical analysis was performed using a linear mixed model, and in the case of significance, the p-value was corrected using the Bonferroni method. Results: There was a statistically significant differences in time up and go test(TUGT), 10m walking, stride and speed between the groups. Conclusions: Long cane length increases body symmetry, stride, increasing muscle activity, and short cane length increases balance and walking.