• 대한치과교정학회지
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• 제23권1호
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• pp.115-122
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• 1993

This study was undertaken to compare the activity of masticatory muscle between normal occlusion and anterior openbite. 33 subjects without the experience of orthodontic treatment, missing teeth and the symptom of T. M. disorders were selected for this study : 25 subjects were normal occlusion and 8 subjects were anterior openbite. The ten items were measured from the cephalometric headplates, and EMG recordings of the anterior temporal and masseter muscle were taken at rest position and during maximum clenching at centric occlusion. All data were analyzed and processed with the computer statistical method. The following results were obtained : 1. At rest position, the muscle activities of both temporal and masseter muscle were higher in anterior openbite than in normal occlusion. 2. During maximum clenching, the muscle activities of both temporal and masseter muscle were prominently lower in anterior openbite than in normal occlusion. 3. At rest position, the temporal muscle of anterior openbite showed the highest muscle activity, but showed the lowest muscle activity during maximum clenching. 4. Anterior openbite showed closer interrelationship between facial morphology and the muscle activity, and the muscle activity was more influenced by the form of mandible than that of maxilla.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1774-1779
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• 2014

It is known that muscle strength of human body can alter or deteriorate as aging. In this study, we present an inverse dynamics simulation to investigate the effect of muscle strength on performing the daily activities. A 3D musculoskeletal model developed in this study includes several segments of whole body, long and short muscles, ligaments and disc stiffness. Five daily activities such as standing, flexion, finger tip to floor, standing lift close and lifting flexed were simulated with varying the maximum muscle force capacities (MFC) of each muscle fascicles from 30 to $90N/cm^2$ with an increment of $30N/cm^2$. In the result, no solution can be obtained for finger tip to floor and lifting flexed with $30N/cm^2$. Even though the solution was available for standing lift close activity in case of $30N/cm^2$ capacity, many of muscle fascicles hit the upper bound of muscle strength which means that it is not physiologically possible to perform the acvities in reality. For lifing flexed, even the case of $60N/cm^2$ capaciy, represents the moderate healthy people, was not able to find the solutions, showing that 18 muscles among 258 muscle fascicles reached 100% of muscle capacity. The estimated results imply that people who have low muscle strength such as elders or rehabilitation patients were required higher muscle work to perform and maintain the same daily activities than healthy one.

• 한국전문물리치료학회지
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• 제16권4호
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• pp.37-43
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• 2009

This study compared the electromyographic activities and input performance of computer operators using a computer mouse and a trackball. Muscle activities were assessed at the upper trapezius (UT), middle deltoid (MD), extensor digitorum (ED), and first dorsal interosseous muscle (FDI). Twenty-six healthy subjects were recruited, and the test order was selected randomly for each subject. The task set was to click moving targets on a Windows program. The EMG amplitude was normalized using the percentage of reference voluntary contraction for UT and MD and the percentage of maximal voluntary contraction for ED and FDI. To analyze the differences in EMG activity, a paired t-test was used. UT muscle activities were significantly greater when the computer mouse was used (p<.05). FDI muscle activities were significantly greater when the trackball was used (p<.05). Using a trackball can reduce the load on the UT during computer work and help to prevent and manage work-related musculoskeletal disorders.

• 한국전문물리치료학회지
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• 제17권4호
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• pp.8-15
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• 2010

This study was designed to investigate the effect of different hand positions on scapulothorcic muscle activities during push-up plus exercises. Fourteen healthy males performed push-up plus exercises under three conditions (neutral, $90^{\circ}$ internally rotated, and $90^{\circ}$ externally rotated hand positions), during which the activities of the serratus anterior, pectoralis major, and upper trapezius muscles were recorded using surface electromyography. The statistical significance at three different hand positions was tested by repeated one-way ANOVA. The mean activities of the serratus anterior increased and the mean activities of the pectoralis major decreased in the order of neutral hand position, internally rotated hand position, and externally rotated hand position. There was a significant difference during push-up plus between neutral and externally rotated hand positions as well as in the serratus anterior/pectoralis major activity ratio (p<.0.5). However, no significant differences were found in the activity of the upper trapezius muscle or the serratus anterior/upper trapezius activity ratio. We suggest that the push-up plus exercise performed in the externally rotated hand position could a beneficial strategy for selective strengthening of the serratus anterior muscle, while minimizing the activity of the pectoralis major muscle.

• 대한물리의학회지
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• 제6권2호
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• pp.145-151
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• 2011

Purpose: The study was designed to investigate the effects of landing heights on muscle activities and ground reaction force during drop landing. Methods: Sixteen healthy adults were recruited along with their written informed consent. They performed a drop-landing task at the height of 20, 40, and 60cm. They completed three trials in each condition and biomechanical changes were measured. The data collected by each way of landing task and analyzed by One-way ANOVA. Ground reaction forces were measured by force flate, muscle activities measured by MP150 system. Results: There were significant differences in ground reaction forces, and significant increases in muscle activities of tibialis anterior, medial gastrocnemius and biceps femoris with landing heights. Conclusion: These findings revealed that heights of landing increases risk factors of body damage because of biomechanical mechanism and future studies should focus on prevention from damage of external conditions.

• Preventive Nutrition and Food Science
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• 제8권4호
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• pp.377-382
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• 2003

This study investigated the effects of green tea on the muscle antioxidative defense system in the white & red gastrocnemius muscles of rats after aerobic exercise. Male Sprague-Dawley rats weighing 150 10 g were randomly assigned to a control group, non-exercise with green tea group (G group), and exercise training group. The exercise training group was then further classified as the training (T) group and training with green tea (TG) group, the latter of which was supplemented with green tea in the drinking water during the experimental period. The rats in the exercise training groups (T and TG) were subjected to aerobic exercise on a treadmill 30 min/day at a speed of 28 m/min (7% incline) 5 days/week, while the other groups (control and G group) were cage confined for 4 weeks. Thereafter, the rats were sacrificed with an injected overdose of pentobarbital just after running. In the white muscle, the xanthine oxidase (XOD) activities were 71 % higher in the T group compared to control group, whereas the TG group had the same activity as the control group. The XOD activities in the red gastrocnemius muscle exhibited the same tendency as in the white muscle. The superoxide dismutase (SOD) activity in the white muscle was lower in the T group compared with the control group, yet significantly higher in the TG group compared with the T group. The SOD activities in the red gastrocnemius muscle exhibited the same tendency as in the white gastrocnemius muscle. The glutathione peroxidase (GSHpx) activities in the white & red gastrocnemius muscles were 43 % lower in the T group compared with the control group, yet the activities in the TG group remained at control levels. The glutathione S-transferase (GST) activity in the white muscle was not significantly different among any of the three groups, but in the red gastrocnemius muscle, the TG group had the same activity as in the control group. The thiobarbituric acid reactive substance (TBARS) contents in the white & red gastrocnemius muscles were higher in the T group than in the control but the control and TG groups had the same concentrations of TBARS. In conclusion, the supplementation of green tea in rats subjected to aerobic exercise was found to reduce the peroxidation of muscle lipids by enhancing the antioxidative defense mechanism.

• 한국운동역학회지
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• 제13권1호
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• pp.95-108
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• 2003

The purposes of this study were to analyze the muscle activities and the characteristics of muscle recruiting patterns of upper trunk for Ssirum dutguri technique using three top-ranked elite Ssirum players. The EMG technique was used to record muscle activities of both right and left sides of latissimus dorsi, biceps brachii, and erector spinae. Six surface electrodes were placed on the surface of the selected muscles and one ground electrode was also attached on the back of neck(C7). One video camera was also used to record the Ssirum motion to define 4 events and 3 phases for further analysis. The raw EMG data were filtered with band pass filter (50-400 Hz) to remove artifacts and then low pass filtered (4 Hz) to find the linear envelope which resemble muscle tension curve. This filtered EMG data were normalized to MVIC for the purpose of comparion between the subjects. The results were indicated that each subject with different physical characteristics showed very different muscle activity patterns. Although Ssirum dutguri is considered as foot technique the player grasped opponent's satba(belt) with both hands when they play. Because of this reason, activities of upper trunk muscles were relatively high. However, direct comparison between upper and lower body muscles was not possible due to the lack of the data in present study. Interestingly, all threes subjects showed that erector spinae muscle activity was comparatively higher than those of latissimus dorsi and biceps brachii. This implies to reinforce back muscle as a routine of training to improve performance or to prevent back injury.

• 한국전문물리치료학회지
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• 제30권2호
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• pp.144-151
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• 2023

Background: The gluteus maximus (GM) muscle comprise the lumbo-pelvic complex and is an important stabilizing muscle during leg extension. In patients with low back pain (LBP) with weakness of the GM, spine leads to compensatory muscle activities such as instantaneous increase of the erector spinae (ES) muscle activity. Four-point kneeling arm and leg lift (FKALL) is most common types of lumbopelvic and GM muscles strengthening exercise. We assumed that altered hip position during FKALL may increase thoraco-lumbar stabilizer like GM activity more effectively method. Objects: The purpose of this study was investigated that effects of the three exercise postures on the right-sided GM, internal oblique (IO), external oblique (EO), and multifidus (MF) muscle activities and pelvic kinematic during FKALL. Methods: Twenty eight healthy individuals participated in this study. The exercises were performed three conditions of FKALL (pure FKALL, FKALL with 120° hip flexion of the supporting leg, FKALL with 30° hip abduction of the lifted leg). Participants performed FKALL exercises three times each condition, and motion sensor used to measure pelvic tilt and rotation angle. Results: This study demonstrated that no significant change in pelvic angle during hip movement in the FKALL (p > 0.05). However, the MF and GM muscle activities in FKALL with hip flexion and hip abduction is greater than pure FKALL position (p < 0.001). Conclusion: Our finding suggests that change the posture of the hip joint to facilitate GM muscle activation during trunk stabilization exercises such as the FKALL.

• 한국전문물리치료학회지
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• 제20권3호
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• pp.19-26
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• 2013

The smart-phone has become a necessity for most people. In this study, we determined that using a smart-phone for 20 minutes can cause increased neck and shoulder muscle activities and fatigue. Seventeen healthy male smart-phone users who attended Yonsei University played a smart-phone game for 20 minutes and changes in their bilateral cervical erector spinae and upper trapezius muscle activities and fatigue were measured. To assess muscle activities and fatigue, we used the following variables: the median frequency, the 50th percentile Amplitude probability distribution function (APDF) value (median load), and the discrepancy in the 90th percentile APDF value and the 10th percentile APDF value (APDF range). A paired t-test was used to compare pre-smart-phone-use status with post-smart-phone-use-status. The median frequency of the bilateral cervical erector spinae and the upper trapezius decreased significantly after 20 minutes of smart-phone use (p<.05). In addition, the 50th percentile APDF value of the bilateral cervical erector spinae and the right upper trapezius increased significantly (p<.05). The APDF range of the bilateral cervical erector spinae and the upper trapezius also increased significantly (p<.05). However, the 50th percentile APDF range of the left upper trapezius was not significantly different (p>.05). These findings suggest that using smart-phones for 20 minutes can induce muscle fatigue and increased neck and shoulder muscle activities.

• The Journal of Korean Physical Therapy
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• 제14권3호
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• pp.74-91
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• 2002

This studies to investigate the effects of ultrasound and swimming on the changes of the serum creatine kinase, latate dehydrogenase, aspatate aminotransferase, alanine aminotransferase, alkaline phosphatase, in peripheral nerve and muscle injury rats. The forty Sprague-Dawley adult male rats were assigned to the 4 groups: the experimental groups(3), and the peripheral nerve and muscle injury control group(1). There was made artificial injured by ischial nerve and muscle of each rats the each experimental ultrasound group and swimming group were treated from 3 days after being injuried for the 5 minutes and 10 minutes every day during the 10 days and 16 days respectively. The results were as follows: 1. The activities of creatine kinase, lactate dehydrogenase were significantly decreased on of the ultrasound and swimming groups for 10 days. All experimental group were significantly decreased for 16 days. there were significantly decreased the swimming group and ultrasound group were to the 10 days group. 2. The activities of asparatate aminotransferase, alalnine aminotransferase on the ultrasound group were significantly increased to the injured control group, there were significantly decreased the ultrasound group for 16 days group were to the 10 days group and there were significantly increased the swimming group for 16 days group were to the 10 days group. 3. The activities of alkaline phosphatase changes were no difference all experimental groups, there were significantly increased for 16 days group to the 10 days group. From these results it may be concluded that the effects of the ultrasound and swimming, the changes of the serum activities creatine kinase , lactate dehydrogenase of (; the objective indicates) to the muscle regeneration process of the nerve and muscle injured rats.