• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.119-127
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• 2023

Objective: This study aimed to compare the activity of the trunk and leg muscles while performing fente (in fencing) wearing weighted and waterbag vests. Method: The electromyography test was used to measure and analyze the activation of the trunk and leg muscles. Eight active fencers from B University (age: 19.5 ± 0.66 years, height: 179.75 ± 5.93 cm, weight: 72 ± 6.32 kg) were selected for this study. Results: According to the EMG analysis results of the 4 muscles measured in this study, left-right differences were observed for rectus abdominis and external oblique abdominis, but left-right differences between the groups were not significant. The gluteus medius muscle was not significantly different from the adductor muscle, but there were significant differences between the groups. Conclusion: The electromyographic analysis of the four muscles measured in this study revealed no significant difference between the left and right recti abdominis and external obliques depending on the vests. However, significant differences were observed between the left and right gluteus medius and adductor longus. Our results can be interpreted as the effects of the inherent movements involved in the fente. Furthermore, our results indicate that the weight transfer while wearing a waterbag vest, which provides an unstable environment, increased the activity of leg muscles.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.235-243
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• 2011

The purpose of the study was to examine the thickness of the trunk muscles ie. external obliques (EO), transversus abdominis (TrA), and multifidus and the trunk endurance strength in order to determine any relationship between the presence or absence of low back pain (LBP) and the size of trunk muscles. Data were obtained from 50 subjects, aged between 19-29 years. Participants had no experience of spinal problems that had resulted in a restriction of normal activity or time-off work and no current spinal symptoms. Measurements of muscle thickness of the trunk muscles were collected at rest, contraction and 15 seconds of post contraction during endurance strength tests. Background information was obtained followed all physical measures. Subjects were divided into two groups based on their experience of LBP. In draw-in maneuver, increasing the thickness of TrA was observed in all participants while EO was decreased at contraction in group 1 and increase in group 2. Only subjects in the group 2 had TrA increased during the flexion endurance test. In the side-bridge endurance test, the thickness of the right TrA was also observed differently between groups. Therefore, the results of the study may suggest that a function of specific muscle should be addressed for training persons with LBP.

• Korean Journal of Applied Biomechanics
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• v.21 no.4
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• pp.467-477
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• 2011

This study was performed to investigate the effects of tibial rotation while going up stair on muscle activity of vastus medialis oblique and vastus lateralis, and on patellar displacement. The subjects included 30 people (male: 15; female: 15) who were randomly assigned to the tibial internal-rotation, neutral-rotation, and external-rotation groups. The subjects went up the stair while performing the assigned rotations, and the rotation of the hip and the displacement of the patella were measured using a 3D motion analyzer. In addition, the maximum voluntary isometric contraction (MVIC) of the vastus medialis oblique and vastus lateralis were measured using surface electromyogram. On the tibial internal rotation, the hip rotation significantly appeared in the same direction and so did on the tibial neutral and external rotations(p<.001). Although the MVIC of the vastus medialis oblique and vastus lateralis did not significantly differ by tibial rotation during the stair ascent, the MVIC of the vastus medialis oblique was higher than that of the vastus lateralis during the internal and neutral rotations (p<.05). In addition, during the stair ascent, the displacement of the patella was more significant during the tibial external rotation than during the tibial internal and neutral rotations(p<.001). Thus, patients with patellofemoral pain are required to be considered the effects of tibial rotation for their rehabilitation.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2413-2419
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• 2015

Core spinal muscles are related to trunk stability and assume the main role of stabilizing the spine during daily activities; strengthening of core muscles around the spine can therefore reduce the chance of back pain. The objective of the study was to investigate the effect of core muscle strengthening in the spine during spine stabilization exercise using a whole body tilt device. To achieve this, a validated musculoskeletal (MS) model of the whole body was used to replicate the input motion from the whole body tilting exercise. An inverse dynamics analysis was executed to estimate spine loads and muscle forces depending on the tilting angles of the exercise device. The activation of long and superficial back muscles such as the erector spinae (iliocostalis and longissimus) were mainly affected by the forward direction (-40°) of the tilt, while the front muscles (psoas major, quadratus lumborum, and external and internal obliques) were mainly affected by the backward tilting direction (40°). Deep muscles such as the multifidi and short muscles were activated in most directions of the rotation and tilt. The backward directions of the tilt using this device could be carefully applied for the elderly and for rehabilitation patients who are expected to have less muscle strength. In this study, it was shown that the spine stabilization exercise device can provide considerable muscle exercise effect.

• 한국체육학회지인문사회과학편
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• v.54 no.1
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• pp.505-514
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• 2015

The purpose of this study was to examine the muscle activation in trunk and low-limbs muscle during squat exercise on various instability surface. 10 subject performed squat with 75% of 1 repetition maximum (1RM) on a stable floor, stability blue, stability black and BOSU. Electromyographic (EMG) activity was measured trunk muscle such as rectus abdomina (RA), external obliques (EO), internal obliques (IO), multifidus (MF), and low-limbs muscle such as gluteus maximus (GMA), gluteus medius (GME), biceps femoris (BF), rectus femoris (RF), vastus medialis oblique (VMO), vastus lateral oblique (VLO), medialis gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL) and anterior tibia (AT) when ascending and descending squat phase. One-way ANOVA repeated measure with Sheffe used to compare the muscle activity on the stable and unstable surface. Squat with BOSU ball induces higher muscle activity of IO, MF, GMA and GME compared with stability and stability blue and blackduring descending motion. Squat with BOSU ball induces higher muscle activity of GMA compared with stability and stability blue and blackduring ascending motion. This results suggested that BOSU ball in the squat could be effective increasing of trunk stability and gluteal muscle activity. However, there was no difference of squat on low-limb muscle with or without instability.

• 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.

• Physical Therapy Korea
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• v.19 no.2
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• pp.80-86
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• 2012

The purpose of this study was to compare the muscle activity of the abdominal and lumbar multifidus during unilateral prone hip extension on the floor and on a round foam roll. Fifteen healthy participants were recruited. They were instructed to perform a unilateral hip extension on the floor and on a round foam roll in the prone position. Surface electromyography (EMG) signals were recorded from bilateral lumbar multifidus (LM), external oblique (EO), and internal oblique (IO) muscles. A paired t-test was used to compare muscle activity, with the level of significance set at ${\alpha}$=.05. The results showed that bilateral LM, EO, IO EMG activity during right-hip extension on a round foam roll was greater than that on the floor, and EMG activity of bilateral LM, right EO, and left IO during left-hip extension on a round foam roll was greater than that on the floor (p<.05). These findings suggest that the unilateral hip-extension exercise on a round foam roll can be used to activate the lumbar multifidus and abdominal oblique muscles and causes a different increasing pattern between the two lifting sides.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.1
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• pp.75-83
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• 2022

PURPOSE: This study was conducted to investigate the effect of the resistance respiratory muscle exercise with transcutaneous electrical nerve stimulation (TENS) on the respiratory muscle tone and pulmonary function of stroke patients. METHODS: Twenty stroke patients were divided into the TENS group (n = 7), placebo TENS group (n = 7), and control group (n = 6), and each intervention was performed on the three groups 5 times a week for 4 weeks. The assessment was carried out by measuring changes in the muscle tone of the latissimus dorsi and abdominal external obliques, and pulmonary function. RESULTS: In this study, the TENS group and the placebo TENS group had significant increases in the paretic side latissimus dorsi muscle tone, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF). There was no significant difference in changes in respiratory muscle tone between the three groups. The pulmonary function was significantly different between the three groups, and it was observed from the results of the post-hoc test that FVC showed a significant increase in the TENS group and the placebo TENS group compared to the control group. CONCLUSION: Through this study, it was found that the respiratory muscle resistance exercise was more effective as a method to increase respiratory muscle tone and pulmonary function in stroke patients than combined transcutaneous electrical nerve stimulation.