• The Journal of Korean Physical Therapy
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• v.31 no.2
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• pp.134-139
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• 2019

Purpose: This study examined the most effective exercise while performing shoulder abduction below ninety degrees. Methods: Thirty two healthy individuals (17 males, 15 females) participated and performed four exercises, 1) Posterior fly, 2) Prone row, 3) Modified prone cobra, and 4) External rotation in the prone position. Surface electromyography (sEMG) was used to measure the electrical activities for the lower, middle and upper fiber of trapezius and serratus anterior. Results: A significant difference in the muscle activities of the upper/middle/lower trapezius and serratus anterior was observed among the three different positions in terms of the PF (posterior fly), PR (prone row), and MPC (modified prone cobra) (p<0.05). In post-hoc analysis, the activities of the lower and upper trapezius were significantly higher than those of the upper trapezius and serratus anterior (p<0.05). In addition, in ERP (external rotation in prone), there was a significant difference in each activity of the muscles. Post-hoc results indicated that the upper trapezius showed greater EMG activity than the other three muscles. Conclusion: External rotation in the prone position revealed the highest activation of the lower trapezius compared to upper trapezius muscle activity. This may be particularly useful in isolating the lower trapezius in cases where excessive scapular elevation is noted. Therefore, the most effective lower trapezius exercise should be performed below ninety degrees of shoulder abduction.

• Animal Bioscience
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• v.34 no.9
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• pp.1514-1524
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• 2021

Objective: This study investigated the meat quality characteristics, endogenous proteolytic enzymes, collagen content, and myosin heavy chain (MyHC) isoforms of different muscles of Thai native cattle (TNC). Methods: Infraspinatus (IF), Longissimus thoracis (LT), and Supraspinatus (SS) muscles were obtained from two TNC breeds, Kho-Lan (KL, n = 7) and Kho-Isaan (KI, n = 7). The muscle and meat characteristics of TNC breeds and their relationship with MyHC expression were examined. Results: Three MyHC isoforms namely MyHC I, MyHC IIa, and MyHC IIx were detected in the muscles. The KL had higher (p<0.05) MyHC IIx than the KI. The IF muscle had higher (p<0.05) MyHC I compared to other muscles. The LT muscle had the least MyHC I. The LT had higher (p<0.05) MyHC IIx than the IF and SS muscles. The IF presented the least MyHC IIx. The KL had higher (p<0.05) lightness and moisture content and lower crude protein, redness, cooking loss, shear force, and calpastatin than the KI. The glycogen, total collagen, soluble collagen, crude protein, ash contents, and troponin T degradation product of IF and SS were lower (p<0.05) than that of LT. Ether extract in LT was lower (p<0.05) than that of IF and SS. The percentage of MyHC I, MyHC IIa, and MyHC IIx were significantly correlated with muscle and meat characteristics of TNC. Conclusion: These results suggest that the differences in the MyHC isoforms may partly account for the variation in meat quality between breeds and among muscles of TNC.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.147-154
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• 2006

This study was conducted to evaluate the effect intentional contraction of abdominal muscles during lifting above shoulder on the muscles activities of the lower trunk and on the degree of lumbar extension. Fifteen healthy adult males were selected as test subjects. A 5kg weight was raised to the shoulder level, 20cm, and 40cm above the shoulder level. EMG activities of all muscles except the rectus abdominis were significantly greater when subjects were asked to contract their abdominal muscles intentionally during lifting(p<0.05). Degree of lumbar extension also significantly decreased with intentional abdominal contraction during the lifting. Also, degree of lumbar extension significantly increased with increase in lifting height(p<0.05). The results of this study show that intentional contraction of abdominal muscles during lifting above shoulder increases the EMG activities of external abdominis oblique, internal abdominis oblique, and erector spinae.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.300-305
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• 2012

Purpose: This study examined the muscle activity of the trunk muscles during weight shifting exercises on a stable and unstable surface. Methods: Ten healthy young subjects (4 males, 6 females) with no medical history of lower-extremity or lumbar spine disease were enrolled in this study. The muscle activity was recorded using surface electromyography (EMG) electrodes from the both sides of the external obliques and erector spinae muscles. Results: The EMG activities of the both rectus abdominalis, both external obliques and erector spinae muscles were significantly higher when the weight shifting exercise was performed on a firm surface than when a balance pad with a balance ball was used. In weight shifting exercises, the EMG activity of the contralateral external obliques and erector spinae muscles was significantly higher than that of the ipsilateral external obliques and erector spinae muscles under all three support surface conditions. Conclusion: Performing weight shifting exercise using an unstable surface is a useful method for facilitating the trunk-muscle strength and trunk stability.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.383-391
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• 2015

Objective : The purpose of this study was to investigate the effects of dynamic squats with slope-whole body vibration (WBV) on the trunk and lower limb in muscle activities. Method : 9 healthy women (age: $21.1{\pm}0.6years$, height: $160.5{\pm}1.4cm$, body weight: $50.5{\pm}2.4kg$) were recruited for this study. Muscle activities in the trunk and lower limb muscles, including biceps femoris (BF), rectus femoris (RF), rectus abdominum (RA), gastrocnemius (GCM), iliocostalis lumborum (IL) and tibialis anterior (TA), were recorded using an EMG measurement system. The test was performed by conducting dynamic squats with slope-WBV using frequency (10Hz, 50Hz), amplitude (0.5mm), and degree ($0^{\circ}$, $5^{\circ}$). Experimental method consisted of 2-pre-sessions and 1-test-session for 20 seconds. Results : The results showed that the muscle activities of the trunk and low limb muscles increased significantly with the $5^{\circ}$ slope and lower frequency (10Hz) except for in the TA. From this result, we confirmed that the slope and WBV could efficiently affect stimulation, enhancing muscle activities by facilitating neural control trail and muscle chain tightness. Conclusion : Utilizing the slope-WBV device while squatting could give positive effects on muscle activation in the trunk and lower limb muscles and provide neural stimulation, enhancing muscle chain of control subsystem through TVR (tonic vibration reflex).

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.3
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• pp.387-394
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• 1994

Journal of the Korean Society of Clothing and Textiles Vol. 18, No. 3 (1994) p. 387∼394 In this study, the restriction of slacks (blue jean) versus box pleats skirt was investigated, from the view point of peripheral blood flow at the toe according to motion variation and E.M.G. analysis of leg muscles after walking on the flat or going up and down stairways. Besides, the pressure of slacks on the lower extrimity was measured statically and dynamically. The main results were summerized as follows; 1. The clothing pressure applied by slacks was; each one of thigh and lower leg was 18.2 g/ cm2 and 22.1 g/cm2 in upright, 63.4 g/cm2 and 26.6 g/cm2 in sitting on the chair, on both sides of thigh and lower leg 272.0 g/cm2 over in squatting. 2. When the motion starts from upright, the dynamic clothing pressure reach their peak before the motions end. When the motion ends and the body comes to a still condition, the clothing pressure grow lower and indicate a constant value. but when the body starts moving again to return to upright, the pressures once grow higher and go to zero value after reaching the peak. The pressure on the knee show much greater than those on the hip. This can be because these pressures depend on the degree of skin stretching motion and of its curvature. 3. The surface E.M.G. in leg muscles M. rectus femoris and M. gastrocnemius were recoreded. In the case of wearing slacks, two muscles were activated much more than wearing skirt. 4. The peripheral blood flow at the toe by wearing slacks was lower than wearing skirt. Also the case when squatting, the peripheral blood flow at the toe was low.

• Physical Therapy Korea
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• v.6 no.2
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• pp.16-31
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• 1999

The purpose of this study was to assess the fatigue in lumbar and abdominal muscles in patients with chronic low back pain compared with normal subjects using spectral analysis with mean power frequency and median power frequency. The experimental group consisted of twenty subjects who had experienced chronic low back pain for over one year after the onset day. A control group consisted of twenty normal subjects with no history of low back pain. All subjects stood in an apparatus to perform sustained contraction in the lumbar and abdominal muscles for 30 seconds with 60% maximal voluntary isometric contraction (MVIC). The resulting electromyographic (EMG) recorded time serial data were transformed into frequency serial data by Fast Fourier Transformation (FFT). The results were as follows: 1) lumbar muscles measured, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group group (p<0.05). In measured two abdominal muscles (inferior rectus abdominis, obliquus externus abdominis) except superior rectus abdominis, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group (p<0.05). 2) In all three (longissimus thoracis, iliocostalis lumborum, multifidus) lumbar muscles measured, the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). In the two (inferior rectus abdominis, obliquus externus abdominis) abdominal muscles measured (superior rectus abdominis not included), the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). These results suggest that in patients with chronic low back pain there is a trend for more fatigue to occur in both lumbar and abdominal muscles than in the normal control group. This would seem to suggest that in treatment programs for patients with chronic low back pain, improvement of endurance in all trunk muscles should be considered.

• The Journal of Korean Physical Therapy
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• v.28 no.2
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• pp.95-100
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• 2016

Purpose: The purposes of this study were to examine muscle activities of trunk and lower limb during squat and 108 bows exercises and to provide objective data for establishing a training method for improving muscle strength of trunk and lower limb. Methods: Twenty normal healthy subjects participated in this study. Each exercise was divided into five periods. Muscle activities of trunk and lower limb in each period of both 108 bows and squat exercises were measured and analyzed by independent t-test. Results: In starting, mid-flexion, mid-extension, and end period muscle activities obtained from 108 bows exercise were significantly higher than those from squat exercise. However, in the final flexion period, muscle activities of multifidus, elector spinae, rectus femoris, biceps femoris, and tibialis anterior from squat exercise were significantly higher than those from bow exercise. Conclusion: In this study, high muscle activities in most muscles of trunk and lower limb were observed from all periods of 108 bows exercise except the final flexion period. Therefore, it is likely that 108 bows exercise rather than squat exercise is more suitable for high strength exercise to improve muscle strength of trunk and lower limb and thus will be applicable for strengthening muscles of trunk and lower limb of patients.

• Journal of the Korean Society of Physical Medicine
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• v.10 no.4
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• pp.81-90
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• 2015

PURPOSE: The purpose of this study was to compare the muscle architecture of serratus anterior and lower trapezius using rehabilitative ultrasound imaging (RUSI) in affected and unaffected side of chronic stroke patients. METHODS: The participants were thirty five patients with stroke hemiplegia in this study. RUSI was used to measure the muscle thickness of the serratus anterior and lower trapezius muscles. We compared the muscle thickness according to affected side and sex, determined the reliability of the measurement image. Independent t-test, intra-class correlation coefficient (ICC) and standard error of measurement (SEM) were used for statistical analysis. RESULTS: Significant difference in muscle thickness of serratus anterior was observed between affected and unaffected side (p<.001). Muscle thickness according to gender showed a significant difference in unaffected side of serratus anterior (p<.05). Compare asymmetry ratio of serratus anterior and lower trapezius muscle thickness showed a significant difference (p<.001). ICC for intra-reliability was .944~.962 in serratus anterior and .873~.925 in lower trapezius muscle thickness, respectively. SEM was .001~.004 in serratus anterior and .002~.008 in lower trapezius muscle. CONCLUSION: This study, using RUSI, showed significant difference in muscle thickness of serratus anterior in affected and unaffected side of stroke patients. RUSI is a practical tool for measuring soft-tissue thickness in the scapular region muscle of stroke.

• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.109-111
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• 1989

An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients.