• 대한물리의학회지
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• 제13권4호
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• pp.123-129
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• 2018

PURPOSE: This study was conducted to investigate the influence of hip abduction angle on the muscle activity of the Gluteus Maximus (GM), Biceps Femoris (BF) and Tensor Fascia Lata (TFL) during Knee Flexed Prone Hip Extension exercise. METHODS: The subjects of this study were 42 healthy individuals. All participant consented to participate in this study. Subjects performed exercise, using the Knee Flexed Prone Hip Extension exercise in three hip abduction position $0^{\circ}$, $15^{\circ}$ and $30^{\circ}$. Subjects rested two minutes, between changing hip abduction position. Data were analyzed using a Noraxon MR-XP 1.08 Master Edition EMG to determine average amplitude, for each angle and muscle. All data were processed by Multivariate analysis of variance (MANOVA). There were a total of three groups. the GM muscle, BF muscle, TFL muscle. RESULTS: GM muscle activity was greatest in the $30^{\circ}$ hip abduction position (p<.05), followed by $0^{\circ}$. Between $0^{\circ}$ and $30^{\circ}$ has significant difference in muscle activity. However, the BF and TFL amplitude were greatest at $0^{\circ}$ hip abduction position followed by $30^{\circ}$. Moreover, the TFL differed significantly between $0^{\circ}$ and $30^{\circ}$, but, BF did not (p<.05). CONCLUSION: Hip abduction at $30^{\circ}$ was found to be the most appropriate position for GM muscle activity.

• 대한정형도수물리치료학회지
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• 제14권2호
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• pp.60-67
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• 2008

Purpose : The purpose of this study is to investigate that the change of lower-limb muscle activity when normal gait and assistive gait of older. Methods : The selected subjects of this study were 11 older who be in good physical health and have not problem to gait and over 60 age to analyze the muscle activity. This study has been conducted to analyze the muscle activity of normal gait and assistive gait in unitary status without any contrast group. We have them gait condition of a gradient of 0% and velocity of 1km/h, 2km/h, 3km/h electrode were attached to the motor point of Rectus femoris, Hamstrings, Tibialis anterior, Calf muscle. When normal gait and assistive gait performs, there are meaningful differences that the muscle activity takes a small drop in Rectus femoris by 9.17% at 1km/h, 9.79% at 2km/h, 13.80% at 3km/h, hamstring by 14.78% at 1km/h, 17.82% at 2km/h, 17.26% at 3km/h, Tibialis anterior by 24.38% at 1km/h, 23.85% at 2km/h, 33.52% at 3km/h, Calf muscle by 13.68% at 1km/h, 16.70% at 2km/h, 18.37% at 3km/h(p<0.05). Results : They show the significant difference in statistical figure. We've received the significant through the comparison between normal gait and assistive gait. These results will be utilized for the preliminary date in the future.

• 한국콘텐츠학회논문지
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• 제18권1호
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• pp.173-184
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• 2018

보행 과정에서 여러 근육이 동시에 수축하는 운동 모듈 또는 근육 시너지는 매우 중요한 중추신경계 운동조절 메커니즘이다. 본 연구는 걷는 동안 근육 간 양성 및 음성 공변 패턴을 이해하는 것을 목표로 한다. 본 연구에서는 트레드밀 보행 시 발생하는 다리 근육 활성을 근전도 검사를 통해 측정하였다. 동시 수축근육 그룹, 즉 운동 모듈을 확인하기 위해 우리는 양쪽 4 개의 다리 근육(전경골근, 내측 비복근, 대퇴직근, 내측 슬괵근)에서 근전도 데이터를 수집하였고, 이를 바탕으로 비음수행렬분해 및 주성분 분석을 수행하였다. 이후 근육 또는 운동 모듈 간의 다양한 조합으로부터 공변이 값을 계산하였고, 이원배치분산분석을 이용하여 각 조합들에서 발생하는 공변이 패턴을 비교하였다. 그 결과, 다양한 조합 사이에 유의미한 공변이 값의 차이가 발견되었다(p < 0.05). 같은 운동 모듈로 정의된 특정 근육 사이에서 발생하는 근 활성은 양성공변이를 보여주었으나 운동 모듈 사이에서는 음성 공변이를 보여주었다. 모든 근육 조합들 사이에서는 음성 공변이가 발생하였다. 운동 모듈 사이에서 안정적으로 발생하는 음성 공변이는 운동 모듈이 복잡한 운동 조정의 제어 단위(control unit) 일 수 있음을 암시하고 있다.

• 한국운동역학회지
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• 제21권3호
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• pp.297-308
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• 2011

The purpose of this study was to investigate the relationship among isometric and isokinetic muscle strength, lean body mass(LBM) and bone mineral density(BMD) in the elderly. Eleven males(age, 70.27${\pm}$5.78yr; height, 167.36${\pm}$6.68 cm; weight, 68.34${\pm}$8.23 kg) and thirteen female(age, 69.77${\pm}$4.13yr; height, 152.80${\pm}$4.45 cm; weight, 56.86${\pm}$7.40 kg) participated in this study. In all subjects, LBM and BMD segments was measured by using Dual-energy x-ray absorptiometry(DEXA, Lunar DPS-DM, U.S.A.). Maximum isometric and isokinetic muscle strength of flexion and extension at the knee and elbow, ankle, trunk joints were measured by using an isokinetic dynamometer(CON-TREX(R) Multi Joint Testing Module, Switzerland). The results of this study showed that isometric and isokinetic muscle strength was significantly higher in extension than flexion. In the male and female, hamstring to quadriceps strength ratio(H:Q ratio) was increased as contraction velocity increased. BMD was correlated significantly with trunk extension in the male, but not in the female. LBM was correlated significantly in the male and female with knee extension strength. This study suggests that in the elderly muscle strength training program should put more weight on extensor muscles of the body.

• 한국전문물리치료학회지
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• 제13권4호
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• pp.56-63
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• 2006

This study examined the effects of the abdominal drawing-in (ADI) maneuver using a pressure biofeedback on muscle recruitment pattern of erector spinae and hip extensors and anterior pelvic tilt during hip extension in the prone position. Fourteen able-bodied volunteers, who had no medical history of lower extremity or lumbar spine disease, were recruited for this study. The muscle onset time of erector spinae, gluteus maximus, and medial hamstring and angle of anterior pelvic tilt during hip extension in prone position were measured in two conditions: ADI maneuver condition and non-ADI maneuver condition. Muscle onset time was measured using a surface electromyography (EMG). Kinematic data for angle of anterior pelvic tilt were measured using a motion analysis system. The muscle onset time and angle of anterior pelvic tilt were compared using a paired t-test. The study showed that in ADI maneuver during hip extension in prone position, the muscle onset time for the erector spinae was delayed significantly by a mean of 43.20 ms (SD 43.12), and the onset time for the gluteus maximus preceded significantly by a mean of -4.83 ms (SD 14.10) compared to non-ADI maneuver condition (p<.05). The angle of anterior pelvic tilt was significantly lower in the ADI maneuver condition by a mean of 7.03 degrees (SD 2.59) compared to non-ADI maneuver condition (15.01 degrees) (p<.05). The findings of this study indicated that prone hip extension with the ADI maneuver was an effective method to recruit the gluteus maximus earlier than erector spinae and to decrease anterior pelvic tilting.

• Physical Therapy Rehabilitation Science
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• 제7권1호
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• pp.41-47
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• 2018

Objective: To investigate the effect of performing three different toe touch (TT) task condition on the activities of four different muscles using surface electromyography (sEMG) in healthy young adults. Design: Cross-sectional study. Methods: A total of 20 healthy young adults (6 males, 14 females) voluntarily participated in this study. All subject randomly performed three different TT task conditions as follows: general toe-touch (GTT) task, one side toe touch (TT) task during weight bearing, and one side foward toe touch (FTT) task during weight bearing. The muscle activities of erector spinae (ES), gluteus maximus (GM), hamstring (HAM), tibialis anterior (TA) muscles during the TT task were measured using sEMG. Subject performed each of the three conditions three time in random order and mean values were obtained. Results: With the trunk flexion period, the TT and FTT showed significantly greater muscle activity in the GM, HAM and TA compared to the GTT task (p<0.05). The TT position showed significantly greater HAM muscle activity than the GTT position. The dominant and nondominant ES muscle activity was significantly greater in the FTT compared to the GTT position (p<0.05). The dominant GM, HAM, and TA was significantly greater in the TT and FTT compared to the GTT position (p<0.05). Although the dominant ES was significantly greater in the TT and FTT compared to the GTT position (p<0.05), the dominant GM muscle activity was signifcantly greater in the TT compared with the GTT position (p<0.05). Conclusions: These findings may be applicable within the clinical field for selective trunk and lower extremity muscle activation and basic biomechanics purpose.

• 한국전문물리치료학회지
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• 제16권4호
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• pp.16-22
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• 2009

The purpose of this study was to investigate the trunk and lower extremity muscle activity induced by three different intensity conditions (intensity 1, 3, 5) of whole body vibration (WBV) during bridging exercise. Surface electromyography (EMG) was used to measure trunk and lower extremity muscles activity. Eleven healthy young subjects (6 males, 5 females) were recruited from university students. The collected EMG data were normalized using reference contraction (no vibration during bridging) and expressed as a percentage of reference voluntary contraction. To analyze the differences in EMG data, the repeated one-way analysis of variance was used. A Bonferroni's correction was used for multiple comparisons. The study showed that EMG activity of the rectus abdominis, external oblique, internal oblique, erector spinae and rectus femoris muscles was not significantly different among three intensity conditions of WBV during bridging exercise (p>.05). However, there were significantly increased EMG activity of the medial hamstring muscle (p=.001) and medial gastrocnemius muscle (p=.027) in the intensity 3 condition compared with the intensity 1 condition. This result can be interpreted that vibration was absorbed through the distal muscles, plantar flexor and knee flexor.

• 대한정형도수물리치료학회지
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• 제19권2호
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• pp.55-60
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• 2013

Background: The purpose of this study was to determine if there is a difference in activation of the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris when performing normal free squat with standinding position and free squat with $30^{\circ}$ flexed hip joint. Methods: Electromyograph surface electrodes were placed on the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris of 19 healthy college students. The participants performed standing bilateral squats and standing bilateral squats with $30^{\circ}$ flexed hip joint with EMG measures taken upon initiation of muscle activity as confirmed by an electronic goniometer. Participants completed one trial with the EMG time measurements on each type. Results: There was a significant difference between normal squats(standing squats) and normal squats with $30^{\circ}$ flexed hip joint. The normal squat exercise was statistically higer than normal squat exercise with $30^{\circ}$ flexed trunk except for semitendinosus and biceps femoris that shown slightly high. Conclusions: As a result of this study, there were increases of muscle activity in both ways. In particular, it may be more beneficial for knee joint stabilization to perform normal squat exercise with standing position relatively.

• 한국전문물리치료학회지
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• 제21권3호
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• pp.38-44
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• 2014

The aim of this study was to investigate the effects of different postural correction in the electromyographic (EMG) activity of the trunk and hip muscles during bridging exercises. Twenty-four healthy subjects volunteered for this study. The muscle activity was recorded with surface electrodes over the erector spinae, multifidus, gluteus maximus (GM), and hamstring (Ham) muscles; it was measured by using surface EMG equipment under the following 3 experimental conditions: manual postural correction, verbal correction, and no correction. The maximal voluntary isometric contraction (MVIC) was determined for each muscle group in order to represent each exercise as a percentage of MVIC and allow for standardized comparison between subjects. A one-way analysis of variance was used to determine significant differences in the EMG activities of each muscle between the 3 experimental groups. During bridging exercises, the manual postural correction on normalized EMG activity of the GM muscle during manual guiding was significantly higher than during verbal guiding and without guiding (p<.05). Furthermore, the GM/Ham ratio was significantly higher during manual guiding than during verbal guiding and without guiding (p<.05). These findings suggest that the activities of the hip and trunk muscles may be favorably modified with manual guiding during bridging exercises.

• The Journal of Korean Physical Therapy
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• 제33권1호
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• pp.1-6
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• 2021

Purpose: This study examined the effects of heel insoles on the static balance and leg muscle activity and posture control strategy during external perturbation. Methods: Thirty healthy young men participated in the study. The subjects underwent two experimental conditions: 1) no heel insole condition (0cm) and 2) wearing heel insole condition (5cm). The static balance was measured using an I-Balance device, which measured the change in the center of gravity (COG). The onset time of muscle activation and muscle activation of the erector spinae (ES), hamstring (HAM), gastrocnemius (GCM) were measured using surface EMG electrodes to determine the change in posture control strategy during external perturbation. Results: The speed and distance of COG were significantly higher in the wearing heel insoles condition than the no heel insole condition (p<0.05). In addition, significant differences in the onset time of the GCM, HAM, and ES muscle activation were observed when there was no heel insole condition during external perturbation (p<0.017). On the other hand, no significant differences in the onset time of muscle activation were observed between GCM and HAM when wearing the heel insole condition during external perturbation (p<0.017). Moreover, muscle activation of the GCM was significantly higher in the wearing heel insoles condition than the no heel insole condition during external perturbation (p<0.05). Conclusion: These findings suggest that heel insoles may have disadvantages, and increased efforts are needed to maintain balance and change the posture control strategy during external perturbation.