• 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 muscle and joint health
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• v.17 no.2
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• pp.142-150
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• 2010

Purpose: The purpose of this study was to examine EMG activities and VMO/VL ratio of the vastus medialis oblique, vastus lateralis, and rectus femoris during squat exercise (knee angle: 15, 45, and 60 degrees; tibial rotation: internal rotation, neutral, and external rotation). Methods: Twelve subjects performed squat exercise at each knee angle and tibial rotation while electromyographic (EMG) activity was collected. Statistical analysis consisted of two-way repeated measures analysis of variance with post hoc analysis. Results: There were significant main effects of knee angles and foot positions and interaction effect on EMG activities of vastus medialis oblique and vastus lateralis. VMO/VL ratios were significantly different by tibial rotations and there was an interaction effect. A neutral position produced significantly more VMO/VL activity ratio than that from internally rotated position and externally rotated position at 60 degrees. Conclusion: Considering the interaction effects for EMG activity across quadriceps muscles tested, the 60 degrees knee angle with a neutral foot position may provide the most effective condition for patients with acute patellofemoral syndrome.

• Electronics and Telecommunications Trends
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• v.37 no.2
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• pp.30-41
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• 2022

As the society is superaging, the number of patients with movement disabilities due to musculoskeletal or nervous system illness is rapidly increasing. To improve public health and reduce medical expenses, it is essential to develop rehabilitation systems that allow patients to resume their daily-life activities. However, the existing musculoskeletal illness diagnosis and rehabilitation method is limited in terms of precision and efficiency because it is based on an empirical diagnosis and prescription without regard for individual characteristics. To overcome these limits, it is critical to design a novel concept of routine rehabilitation therapy device that is capable of inducing musculoskeletal balance by the precise analysis of musculoskeletal usage patterns via the motion and the muscle activity tracking of linked muscles. This study introduces the trend of on-skin sensor device technology for routine musculoskeletal monitoring and therapy. For on-skin rehabilitation systems, skin-adhesive and stretchable motion/posture, electromyography, pressure sensors, small-size and low-power wireless sensor interfaces, and user-friendly rehabilitation contents based on new algorithms are combined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.224-230
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• 2016

The purpose of this study was to examine the effects of height of the shoe heel in a one leg standing posture on the muscle activity of the rectus abdominis, erector spinae, hamstring, and rectus femoris. Twenty healthy female subjects were asked to perform a one leg standing posture with three types of shoes, which had different heights of shoe heel, 0cm, 3cm, and 7cm. Surface electromyography was used to evaluate the activities of the right rectus abdominis, erector spinae, hamstring, and rectus femoris muscles. The data was analyzed by repeated one-way ANOVA and the muscle activities among three heights of shoe heel were compared. The results showed that the muscle activities of the erector spinae and rectus femoris increased significantly according to increase height of shoe heel (p<0.05). The activity of the rectus abdominis and hamstring were not significantly different among the three height of shoe heel (p>0.05). These results suggest that the height of shoe heel affects the lumbo-pelvic alignment and center of mass; therefore, high-heeled shoes lead to musculoskeletal pain in the lumbopelvic, hip, and knee areas.

• Journal of Korea Entertainment Industry Association
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• v.14 no.1
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• pp.17-25
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• 2020

The purpose of this study was to examine the effects of coordinative locomotor training (CLT) program on the balance for the promotion of life care of elderly obese women. Ten participants of elderly obese women who were able to walk independently without surgery experience of lumbar, hip or knee joint within the past year were recruited and under went the pretest, CLT (20 sessions), followed by the post-test. The test included BMI test using In-body, joint kinematics using myoVIDEO, muscle activation using surface EMG test (erector spinae (ER), external oblique abdominalis (EO), quadriceps femoris (Quad), hamstring muscle (Ham)) and balance tests including dynamic balance test using forced treadmill, Berg balance scale (BBS) and timed up go (TUG). The CLT program was conducted 60 minutes a day, 5 days a week, over 4 weeks period. As a result of this study, The the trunk and hip joints kinematics during the stance and swing phases of gait were a statistical significance levels were set at p <0.05. The ER and EO muscle activation were significantly improved after intervention (p <0.05). The length of gait line and single support line of change of center of pressure (COP) were significantly increased after intervention (p <0.05). The BBS and TUG were also significantly enhanced after intervention (p <0.05). The results of this study showed that CLT program for the improvement of life care had significant effects on improving postural instability, muscle weakness, reduced balance ability and falling risk of obese elderly women. Therefore, it is recommended to apply CLT program to improve life-care through improving balance ability and preventing fall of obese elderly women.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.435-441
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• 2012

This study is intended to provide a basic clinical data useful for preventing shoulder injuries related to occupation and curing them, by measuring the shoulder muscle activity of normal adults in an arm posture type of a wide shoulder joint angle, according to several differences of hand grip force. In order to examine the shoulder muscle activity during hand grips at a variety of intensity, according to the arm posture type, MVCs of all subjects were measured, and %MVCs of anterior deltoid, supraspinatus, the upper trapezius and infraspinatus at 0 degree, 90 degrees and 160 degrees of shoulder angle were yielded according to the grip force in an arm posture type, changing the maximum grip force into 30%, 50% and 90%, randomly. When measuring the hand grip at 30%, 50% and 70% of the maximum grip force to compare %MVC of each group depending on the arm posture type, there were no significant differences of muscle activity at 0 degree of shoulder angle among anterior deltoid, supraspinatus, the upper trapezius and infraspinatus, but there were significant differences of it among them at 90 degrees and 160 degrees of should angle(p<.001). According to the results of post-hoc test, also, anterior deltoid had the highest muscle activity, whereas the upper trapezius had the lowest muscle activity.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.81-85
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• 2009

Work related musculoskeletal disorders(WMSDs) was a leading cause of sick leave and injuries in the industries of our country. Posture was an important consideration in the design of work method and workplaces, because it affected the ability of workers to use various equipments and influenced how long they could perform their job without feeling discomfort, fatigue, and musculoskeletal disorders. Imbalanced lower limb postures such as a squatting posture were awkward working postures common to the shipbuilding shops, farms, automobiles assembly lines in our country. Different awkward working postures were known to be associated with specific musculoskeletal disorders. Eight postures in lower limb postures divided into balanced and imbalanced postures were evaluated by electromyographic(EMG) activity for lower limb muscles. Twelve male subjects participated in this study. This paper was to analyze the effects of lower limb muscles workload according to lower limb postures(knee angle) and working time. The ANOVA results showed that most EMG root mean square(RMS) values were statistically significant effect according to lower limb postures(knee angle) and working time. Therefore, the results of this study will provide the basis to evaluate workload of lower limb postures correctly adopted by workers in various jobs and the ergonomic reference to prevent WMSDs.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.245-253
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• 2008

The purpose of this study was to analyze the effects of shoes with curved out-sole on the posture variation and its control strategy. At first, Target shoes(s) was made by evaluating the static postures of 7-female university students via 'New York State Posture Test' on shoes which made the relative angle between foot surface and ground surface of shoe change. At second, we evaluated muscle activity for 30-female university students(10 persons-3 groups) on shoes which were s(target), m shoes with curved out-sole and n shoes with flat out-sole. 1. The posture scores on New York State Posture Test were statistically different according to the relative angle changes, and the best angle for score was -7 degree but, the scores charts were like two humped camel at -2, -7degree. we made the shoe with -7 degree and curved out-sole. 2. s, m shoes with curved out-sole had graded muscle activities but, static posture on bare foot, there were the graded activity on gastrocnemius for s shoes and tibialis anterior for m shoes, but on shoes, only Gastrocnemius for s shoes.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.3
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• pp.331-339
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• 2013

The Interest in disease prevention and rehabilitation is increasing depending on increase of patients with spinal. This is being developed using the spine stabilization device is being studied. So far studies have only evaluated the effect on trunk stabilization exercises but analysis of human movement patterns for active movement and passive movement did not. We assessed the muscle activity of trunk and leg muscle during passive and active tilt mode on eight tilt directions at tilt angle of $30^{\circ}$ using 3-D dynamic postural balance training system. We performed experimental study on the muscular activities of trunk muscle about rectus abdominis, external obliques, latissimus dorsi, erector spinae, and leg muscle about rectus femoris, Biceps femoris, Tibialis Anterior, gastrocnemius. As a result, muscle activation was different depending on the direction of movement and pattern. The results indicate that various patterns of spinal stabilization exercise system could be applied to an effective training of chronic low back pain patients.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.9-16
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• 2002

Localized muscle fatigue can be identified by a downward shift of the EMG frequency typically represented by a fall in the median frequency The Present experimental study was Performed to investigate the time change of the median frequency and the muscle torque during maximal isometric back extension exercises at different exercise angles (0$^{\circ}$, 12$^{\circ}$, 36$^{\circ}$and 72$^{\circ}$) Twenty heath subjects (mean age : 24.35 $\pm$ 2.70) were Participated in this study Median frequency was extracted from EMG signals by employing the fast Fourier transform. Initial median frequency and the slope of median frequency was not significantly correlated with the muscle torque. Pearson's Product moment correlation was used to quantify the relationship between slopes of median frequency and torque. The results may suggest that the exorcise angle during maximal isometric back extension exercises does not affect the slopes of the median frequency and torque, and y-intercept of the median frequency among exercise angles There was no significant correlation between slopes of median frequency and torque. But there was a moderate correlation between median frequency and torque at each exercise angle. In conclusion, the exercise angle during maximal isometric back extension exercise is not a direct effect on slopes of median frequency and torque. But results showed that the shift of median frequency and torque shift were highly correlated in all subjects.