• The Journal of Korean Physical Therapy
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• 제34권4호
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• pp.187-191
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• 2022

Purpose: The purpose of our study aimed to identify the effect of static and dynamic bridge exercise with gym ball using gym ball on muscle activation of trunk and lower-limb in healthy individuals. Methods: A total of 20 healthy adults participated in this study. The individuals performed general bridge exercise, static and dynamic bridge exercise using gym ball. During the three methods of bridge exercises, electromyography (EMG) data (% maximum voluntary isometric contraction) of the rectus abdominis, erector spinae, biceps femoris, and gastrocnemius were recorded using a wireless surface EMG system. Results: Rectus abdominis activation showed significantly greater during dynamic bridge exercise compared with general bridge exercise and dynamic bridge exercise. Erector spinae, biceps femoris, and gastrocnemius were greater during static and dynamic bridge exercise compared with general bridge exercise. Conclusion: Based on our results, bridge exercise using gym ball, particularly integrating lower-limb movement, could be a useful method to enhance muscle activation of trunk and lower-limb (rectus abdominis, erector spinae, biceps femoris, and gastrocnemius).

• The Journal of Korean Physical Therapy
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• 제35권2호
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• pp.53-57
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• 2023

Purpose: The purpose of this study was to compare the changes in the muscle activation of the quadriceps muscle (rectus femoris, vastus lateralis, vastus medialis) during the stand-to-sit (StandTS) movement according to the plantar flexion angle of the ankle joint. Methods: A total of 22 healthy young females participated in this study. During the StandTS under the three conditions (plantarflexion angle 0°, 20°, and 45° of the ankle), electromyography (EMG) data (% maximum voluntary iso¬metric contraction) of the rectus femoris, vastus lateralis, and vastus medialis were recorded using a wireless surface EMG system. Results: There was a significant difference in the muscle activation of rectus femoris, vastus lateralis, and vastus medialis according to the plantar flexion angle (0°, 20°, and 45°) of the ankle. The muscle activation of the quadriceps was the highest at a 45° angle of plantarflexion and the lowest at 0°. One-way repeated ANOVA was used to analyze the muscle activation data of the lower extremity muscles according to the angle of the ankle joint. Conclusion: Based on the results of our study, it was confirmed that the muscle activity of the quadriceps can be increased even in the StandTS movement, which involves the eccentric contraction of the quadriceps muscle. This suggests that maintaining a plantar flexion posture for a long time, say by wearing high-heeled shoes, can quickly cause muscle fatigue in the lower-limb muscles, which can cause a decrease in balance ability leading to falls.

• 대한산업공학회지
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• 제7권2호
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• pp.3-17
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• 1981

Isometric muscle strength has become important as it is realized that a large variation in the human exists and is affected by many personal and environmental factors. Experiments have been performed for estimating the individual capabilities of the quadriceps femoris muscle in man. The surface EMG has been recorded on the belly of the rectus femoris muscle during voluntary isometric continuous exertion at 25%, 50%, 75%, and 100% MVC. As a muscle force (% MVC) increases, the rectified mean EMG amplitude increases in a non-linear form. The rectified mean EMG amplitude also increases in a non-linear with respect to fatigue progression. As the muscle force (% MVC) increases, an endurance time of isometric exertion decreases linearly. Analysis shows that rectified mean EMG amplitude is a consistent and sensitive measure of motor unit recruitments and can be useful in estimating an individual capability of a local muscle. Further, the result satisfies the sufficient condition that type S motor units are recruited first, while large motor units are recruited progressively as the fatigue develops.

• PNF and Movement
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• 제10권3호
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• pp.25-31
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• 2012

Purpose : This study was intended to compare muscle activity in relation to knee joint angles on closed kinetic chain. Methods : A total of 13 subjects consisting of 5 adult males and 8 adult females were made to make movements maintaining knee joint angles at $30^{\circ}$, $45^{\circ}$ and $90^{\circ}$ on closed kinetic chain and the muscle activity occurring in their vastus medialis, rectus femoris and vastus lateralis was measured. Statistical data were analyzed using oneway ANOVA. Results : On closed kinetic chain, the muscle activity of the vastus medialis, rectus femoris and vastus lateralis increased the most at $90^{\circ}$ among the knee joint angles with statistically significant differences(p<0.05). Conclusion : On closed kinetic chain, it could be seen that as the angle of the knee joint increased, the muscle activity increased.

• 한국운동역학회지
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• 제25권1호
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• pp.77-84
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• 2015

Objective : The purpose of this study was to analyze the effects of lower limb muscle activity on postural stability and ground type in elderly women subjects. Method : Forty two subjects participated in the experiment (high group - age: $74.29{\pm}4.13yr$, height: $152.44{\pm}5.54cm$, weight: $57.43{\pm}6.16kg$, BMI: $24.77{\pm}2.99$, low group - age: $77.67{\pm}5.16yr$, height: $151.40{\pm}3.93cm$, weight: $60.92{\pm}6.40kg$, BMI: $26.59{\pm}2.57$). Wireless EMG with eight channels was used. Ground types were classified as flat and cushion. Results : In the double-support phase, left and right rectus femoris, left biceps femoris, left and right tibialis anterior, and left gastrocnemius did not show a significant difference in postural stability according to ground type. However right biceps femoris and gastrocnemius showed higher muscle activity in the elderly women group with lower postural stability. In the single-support phase, left and right rectus femoris, right biceps femoris, and left and right tibialis anterior did not show a significant difference in postural stability according to ground type. In addition, left biceps femoris had higher muscle activity in the elderly women group with lower postural stability. Left gastrocnemius had higher muscle activity in the elderly women group with higher postural stability and right gastrocnemius had higher muscle activity in the elderly women group on cushion ground. Conclusion : In a dynamic postural stability and cushion ground, biceps femoris and gastrocnemius muscle activity were high. As a result, biceps femoris and gastrocnemius muscle strengthening exercise on cushion ground could be beneficial in the prevention of falling.

• 한국응용과학기술학회지
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• 제35권3호
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• pp.905-913
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• 2018

본 연구는 필라테스 동작 시 폼롤러의 적용과 움직임에 따른 몸통과 하지의 근활성도 차이를 알아보는 것이 목적이다. 피험자로 남자 8명을 선정하여 필라테스 네발자세, 교각자세, 코어컨트롤 동작을 매트위에서 정적동작, 폼롤러 위에서 정적동작, 폼롤러 위에서 동적동작으로 무선배정하여 1주 간격으로 수행하였다. 각 동작의 수행 시 척추세움근, 배곧은근, 배바깥빗근, 중간볼기근, 넙다리두갈래근과 넙다리곧은근의 근활성도를 측정하여 일원분산분석으로 분석하였다. 유의수준은 ${\alpha}=.05$로 설정하였다. 첫째, 네발기기 동작에서 폼롤러 동적동작에서는 배곧은근, 배바깥빗근, 중간볼기근, 넙다리두갈래근의 근활성도가 높게 나타났으며(p<.001)(p<.05), 폼롤러 정적동작에서는 넙다리곧은근의 근활성도가 높게 나타났다(p<.001). 둘째, 교각자세 동작에서 폼롤러 동적동작에서는 넙다리두갈래근의 근활성도가 높게 나타났다(p<.001). 셋째, 코어컨트롤 동작에서 폼롤러 동적 동작에서는 배곧은근, 척추세움근, 중간볼기근의 근활성도가 높게 나타났으며(p<.001)(p<.01), 정적 동작에서는 배바깥빗근의 근활성도가 높게 나타났다(p<.05). 필라테스 운동시 근활성도를 고려하여 방법과 난이도를 적용하면 더욱더 효과적일 것이라 사료된다.

• 한국융합학회논문지
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• 제12권6호
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• pp.27-32
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• 2021

본 연구의 목적은 전기근육자극을 적용한 무릎 폄 저항운동 시 넙다리곧은근의 두께 변화에 미치는 즉각적 효과를 알아보고자 하였다. 20명의 건강한 성인을 대상으로 유사실험 단일집단 검사전-검사후 설계로 진행하였다. 대상자의 양쪽 넙다리 폄의 1RM을 탄력밴드를 이용해 간접적으로 측정하고, 탄력밴드를 이용한 무릎 폄 저항운동은 오른쪽 다리에 고강도(1RM의 80%)로, 왼쪽 다리에는 저강도(1RM의 50%로 전기근육자극을 같이 적용)로 5세트를 적용하였다. 근육 두께 측정은 초음파로 운동 전후에 넙다리곧은근(1/2 부위, 1/4 부위)에 측정하였다. 사전 테스트와 사후 테스트 사이에 전기근육자극을 적용한 탄력밴드 저강도 운동에 넙다리곧은근 두께가 통계적으로 유의한 차이가 있었다(p<.05). 본 연구의 결과는 전기근육자극을 결합한 탄력밴드 저강도 저항운동이 넙다리곧은근 두께를 증가시키는 데 즉각적인 효과가 있었다. 이 결과를 바탕으로 앞으로 고강도 저항운동을 할 수 없는 노령층에 전기근육자극을 적용한 저강도 저항운동을 접목하는 중재 방법의 효과에 대한 검증과 다양한 신체 부위별 운동프로그램 개발도 필요하다 여겨진다.

• 한국산학기술학회논문지
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• 제13권1호
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• pp.220-226
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• 2012

본 논문은 만성 뇌졸중 환자의 트레드밀 경사도 훈련이 하지 근육의 활성도에 미치는 영향을 알아보기 위한것으로 32명의 대상자를 무작위로 대조군인 $0^{\circ}$훈련군 10명과 실험군인 $5^{\circ}$훈련군 10명과 $10^{\circ}$훈련군 12명으로 나누어 실험하였다. 6주간의 훈련 후 하지 근육 중 넙다리곧은근, 넙다리두갈래근, 앞정강근, 장딴지근의 활성도 정도를 근전도를 통해 검사하였다. 연구의 결과 넙다리곧은근과 장딴지근은 각 그룹에서 각각 의미있는 변화를 보였지만 넙다리두갈래근과 앞정강근은 실험군에서만 의미있는 변화를 보였다. 또한 각 그룹간 비교에서는 넙다리곧은근이 대조군과 $5^{\circ}$훈련군 사이에서 앞정강근이 대조군과 $10^{\circ}$훈련군 사이에서 의미있는 변화를 보였다. 따라서 트레드밀 경사도 보행 훈련이 하지 근육의 활성화에 효과가 있음을 알 수 있다.

• 대한물리의학회지
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• 제12권1호
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• pp.61-66
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• 2017

PURPOSE: The purpose of this study was to investigate the effects of isometric upper limb contraction on the trunk and lower extremity muscles during the sit-to-stand activity in elderly females. METHODS: Eighteen healthy elderly females performed three directional isometric upper extremity contractions (flexion, extension, and horizontal abduction movements) using an elastic band during sit-to-stand activity. Electromyography signals were collected from the internal oblique, erector spinae, rectus femoris, and biceps femoris muscles. RESULTS: Internal oblique activity was greater in bilateral shoulder flexion and bilateral shoulder horizontal abduction than in neutral position (p<.05). Erector spinae and rectus femoris muscle activities in bilateral shoulder flexion was greater than in neutral position and bilateral shoulder extension (p<.05). Biceps femoris activity was significantly greater in bilateral shoulder flexion than in bilateral shoulder extension and horizontal abduction, and in neutral position compared to bilateral shoulder extension (p<.05). CONCLUSION: These results suggest that incorporating isometric upper limb contraction may be beneficial for enhancing the contribution of trunk and lower extremity muscle activities to trunk stabilization during sit-to-stand activity. Therefore, isometric upper limb contraction during sit-to-stand tasks, especially in flexion, may be used to elicit contraction of the lumbopelvic region muscles within a tolerable range, for developing endurance and strength in the elderly.

• 대한물리치료과학회지
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• 제7권2호
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• pp.697-709
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• 2000

이 실험의 목적은 Electro-Myoscope 이 과다 사용에 의해 일어나는 대퇴사두 근육 통증에 미치는 효과에 대해 근전도를 이용한 연구입니다. 이를 위해 나이 15세부터 50세 사이의 18명의 여성 자원자들이 참여했다. 대퇴직근을 Cybex 운동기기를 사용해 Terminal knee extension 운동을 통해 과다사용으로 인한 통증이 유발되게 하였다. 그리고, Electro-Myoscope을 치료 후 근전도를 통해 대퇴사두근의 motor recruit 에 대해 기록 비교하였다. t-test 와 Chi square 분석 결과 대퇴사두근의 기능이 향상된 것으로 나타났다.