• PNF and Movement
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• v.9 no.3
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• pp.11-17
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• 2011

Purpose : The purpose of this study was to analyze the effects of proprioceptive neuromuscular facilitation (PNF) leg flexion patterns according to the hip joint angle on electromyographic activity of the trunk. Methods : Thirty healthy adults volunteered to participate in this study. Subjects were required to complete following the PNF leg flexion patterns on three different hip joint flexion $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$. An surface electromyogram (SEMG) was used to record the electromyographic activities of the trunk muscle in rectus abdominis, internal oblique abdominal, external oblique abdominal, erector spinae. The data were analyzed using the a repeated measures of one-way ANOVA with post-hoc Bonferroni's correction. Result : The results of this study are summarized as follows: The EMG activities of internal abdominal oblique and elector spinae muscle showed a statistically significant difference (p<.05). Conclusion : The result show that electromyographic activity of the trunk muscles significantly changed on PNF leg flexion patterns with difference hip joint angle. Therefore, this study used to basis for the intervention of the trunk muscle strength and stabilization.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.197-205
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• 2007

The purpose of this study is to analyze the muscle activations and Ground Reaction Force(GRF) in university judo players, and provide the guide of training in Judo. Using surface electrode electromyography(EMG), we evaluated muscle activity in 5 university judo players during the Judo Uke Movements. Surface electrodes were used to record the level of muscle activity in the Tibialis Anterior, Rectus Femoris, Elector Spinae, Gluteus Maximus, Gastrocnemius muscles during the Uke. These signals were compared with %RVC(Reference voluntary contraction) which was normalized by IEMG(Integrated EMG). The Uke was divided into four phases : Kuzushi-1, Kuzushi-2, Tsukuri, Kake. The results can be summarized as follows: 1. The effective Uke Movements needs to short time in the Kake Phase 2. The Analysis of Electromyography of Uke Movements in Supporting Leg; TA(Tibialis anterior) had Higher %RVC in the Kuzushi Phase, RF(Rectus Femoris) had Higher %RVC in the Tsukuri Phase, GM(Gluteus Maximus) had Higher %RVC in the Kake Phase 3. The ground reaction force for Z(vertical) direction was showed increase tendency in Kuzushi phase, Tsukuri phase and decrease tendency in Kake phase.

• 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.

• The Journal of Korean Physical Therapy
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• v.24 no.5
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• pp.348-354
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• 2012

Purpose: This study examined the effects of computerized feedback postural training on the balance and electromyography activity of subjects with stroke. Methods: A total of 30 chronic stroke patients were enrolled in this study. Subjects were divided into an experimental group (n=15) and a control group (n=15). Computerized feedback postural training was used in the experimental group. Both groups received intervention for six weeks, 5 times per 30 minutes period. Data analysis was performed using analysis of covariance for determination of statistical significance. Results: Significant difference in static and dynamic balance was observed in the experimental group, compared with the control group (p=0.05), and a significant difference in muscle activity was observed in the gastrocnemius muscle, quadriceps muscle, and elector spinae muscle. However, the hamstring muscle showed no significant difference. Conclusion: Computerized feedback postural training is more effective in improving the ability of balance and muscle activity than neurological physical therapy.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.316-321
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• 2013

Purpose: The aimed of this study was to investigate muscle activation related to postural stability according to different frequency of whole body vibration during quiet standing, to identify the most effective training conditions that cause the highest neuromuscular responses, and to evaluate the difference of EMG activation according to the anatomical position of the muscle - proximal or distal from the vibration platform. Methods: Eighteen healthy subjects voluntarily participated in this single-group, repeated-measures study in which EMG data from upper trapezius, rectus abdominalis, external oblique abdominalis, elector spinae, gluteus maximus, rectus femoris, semitendinosus, and gastrocnemius were collected over different frequencies (0-5-10-15-20-25Hz) for each subject during quiet standing. Results: We observed a statistically significant difference in the mean values of %RVC of muscular activation according to different frequencies of whole body vibration during quiet standing in all muscles (p<0.05). Conclusion: Our results indicate that lower frequencies of vibration result in low muscular activation, and higher frequencies elicit high muscular activation. However, the most effective training condition that caused the highest activation was 20 Hz. In addition, the proximally located lower extremity muscles (GCM, RF, ST, GM) showed higher activation than the distally located trunk and neck muscles (ES, EO, RA, UT) together with increasing frequency.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.407-414
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• 2010

The purpose of this study was to evaluate the effect of taping-tape with or without using spiral taping on vertical jump. The subjects for this study were about 20 years old healthy male college students without muscloskeletal diseases. Data for EMG activity and Ground Reaction Force(GRF) were estimated at three knee angles(i.e., 45, 90 & full degree). As a result, there was no statistical significance in max GRF at 90 and full degree regardless of spiral taping-tape. On the other hand, statistical significance was found when vertically jumping at 45 degree knee angle(p<.05). All the data for EMG activity at the three knee angles were not statistically significant, but there was a trend for a decrease in average EMG activity in elector spinae & Medial gastrocnemius at 90 degree knee angle. Based on these data, initial flexor action of knee was stabilized with spiral taping-tape when vertically jumping, resulting in improved muscular activity in Medial gastrocnemius. In conclusion, taping technique for jumping ability associated muscles like quadriceps is also required to develop.

• Physical Therapy Korea
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• v.11 no.3
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• pp.43-50
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• 2004

This study was designed to determine the effects of different widths in the base of support (BOS) on trunk and lower extremity muscle activation during upper extremity exercise. Twenty-seven healthy male subjects volunteered for this study. Exercises were performed for a total of 10 trials with a load of 10 repetitions maximum (10 RM) for each of the various widths of BOS (10 cm, 32 cm, 45 cm). The width of a BOS is the distance between each medial malleoli when a subject was in a comfortable standing position. Electromyography was used to determine muscle activation. Surface bipolar electrodes were applied over the tibialis anterior, medial gastrocnemius, biceps femoris, rectus femoris, gluteus maximus, upper rectus abdominis, and elector spinae muscle. Electromyographic (EMG) root mean square (RMS) signal intensity was normalized to 5 seconds of EMG obtained with a maximal voluntary isometric contraction (MVIC). The data were analyzed by atwo-factor analysis of variance (ANOVA) with repeated-measures ($3{\times}7$) and Bonferroni post hoc test. The results were as follows: (1) There were significant differences in the width of the BOS (p=.006). (2) The post hoc test showed significant differences with the BOS between 10 cm and 32 cm, between 10 cm and 45 cm and between 32 cm and 35 cm (p=.008, p=.003, p=.011). (3) There was no interaction with the BOS and muscle. (p=.438) There were no significant differences in the muscle activation (p=.215).

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.283-291
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• 2010

The purpose of this study was to investigate the effect of foot placement and height of bed surface on lumbar spine load in a dummy transfer activity. Fifteen healthy male students participated in this study. All subjects were involved in four different conditions according to foot placement (11 figure and $90^{\circ}$ figure) and height of bed surface (44 cm and 66 cm) randomly. Muscular activations of the biceps brachii, rectus femoris, elector spinae using surface-EMG, vertical ground reaction using force plate, and L4/L5 compression force using 3DSSPP (3D Static Strength Prediction Program) were measured and analysed. The results showed that muscular activations were not significantly different for the various conditions except for the rectus femoris on the right side (p<.05). Futhermore, the vertical ground reaction and L4/L5 compression force were significantly different conditions (p<.05). In conclusion, it is suggested that foot placement at $90^{\circ}$ figure is safer for transfer activity compared with the 11 figure.

• Journal of Korean Physical Therapy Science
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• v.10 no.2
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• pp.96-103
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• 2003

The purpose of this study was to assess the effect of applied pressure to abdomen on lumbar and abdominal muscle activation during upper limb exercise. The experimental group consisted of twenty-seven healthy male subjects (mean age=$22.40{\pm}2.19years$, mean height=$175.30{\pm}2.19cm$, mean weight= $67.67{\pm}7.44kg$, RM=$8.43{\pm}2.76kg$). In each different pressure condition (OmmHg, 30mmHg, 70mmHg, 100mmHg), upper limb exercise was performed in total of 10 trials with 10 RM dumb-bell exercise. Lumbar and abdominal muscle activity was measured using surface bipolar electrode electromyography(EMG). EMG activity was measured from upper rectus abdominis, external oblique abdominis, internal oblique abdominis, and elector spinae. The raw EMG signal was processed into the root mean square(RMS). All RMS EMG data were normalized and express as a percentage of the EMG(%EMG). Collected data were statistically analyzed by SPSS/PC Ver 10.0 using two-way analysis of variance for repeated measures($4{\pm}3$) and Bonferroni post hoc, test. Lumbar and abdominal muscle activation was significantly increased when 100 mmHg was applied(p<.05). Upper rectus abdominis activation was significantly increased compared as other muscles activation(p<.05). However, there were no interaction between pressure and muscles(p>.05). The findings of this study can be used as a fundamental data when lumbar orthosis is applied and external pressure can be used as a therapeutic tool.

• PNF and Movement
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• v.15 no.3
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• pp.303-310
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• 2017

Purpose: This study observed the activity of trunk and lower limb muscles during a modified bridging exercise with various weight loads. Methods: The participants in this study consisted of 15 male adults. The muscle activity of the elector spinae, rectus abdominis, gluteus maximus, gluteus medius, vastus medialis, vastus lateralis, tibialis anterior, and soleus muscles was measured with an EMG-8 system during a modified bridging exercise performed with various weight loads (indicated as percentage of body weight). Differences in muscle activity during the bridging exercise according to the weight load applied were analyzed using a one-way ANOVA, and post hoc analysis was performed using LSD. Statistical significance was accepted at a p-level of 0.05. Results: When the subjects performed the modified bridging exercise with various weight loads, the muscle activity of the gluteus maximus and vastus medialis peaked at a load of 0.5%. The activity of the gluteus medius showed a remarkable difference when the modified bridging exercise was performed at loads of 0% and 0.5%, 0% and 1%. In addition, the activity of the vastus medialis showed a remarkable difference between modified bridging exercises performed at a load of 0% and that performed at a load of 0.5%. Conclusion: The results suggest that performing modified bridging exercises with a load of 0.5% of body weight results in significant differences in the activity of the gluteus medius and vastus medialis muscles. Thus, it is suggested that performing the modified bridging exercise at 0.5% of body weight may selectively strengthen the gluteus medius and vastus medialis muscles.