• 한국전문물리치료학회지
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• 제12권2호
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• pp.11-19
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• 2005

Patellofemoral pain syndrome (PFPS) is often attributed to malalignment and maltracking of patella within the patellofemoral joint. Most exercise for PFPS has focused on selectively strengthening the vastus medialis oblique muscle (VMO). This study was designed to identify the effect of medial, lateral wedge and difference of Quadriceps angle (Q-angle) on vastus medialis oblique/vastus lateralis muscle (VL) activity ratios. The subjects were twenty young adult males who had not experienced any knee injury. They were asked to perform isometric contraction exercises in three postures using medial and lateral wedge. The EMG activity of the VL and VMO were recorded in three postures by surface electrodes and normalized by %MVC values derived from seated, isometric knee extensions. The normalized EMG activity levels (%MVC) of the VL and VMO for the three postures of the lower extremities were compared using 2-way repeated measures ANOVA with 1 between-subject factor (group), and 1 within-subject factor (wedge). Results of repeated measures of ANOVA's revealed that the medial wedge isometric contraction exercise produced significantly greater EMG activity of VMO/VL ratios in Group I (Q-angle $18^{\circ}$ or less) (p<.05). But, the medial wedge isometric contraction exercise was no significant difference of VMO/VL ratios in Group II (Q-angle $19^{\circ}$ or more) (p>.05). These results have important implications for selective VMO muscle strengthening exercises in PFPS patients.

• 한국운동역학회지
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• 제27권2호
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• pp.83-90
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• 2017

Objective: To investigate the effect of short-term vibration frequencies on muscle force generation capabilities. Method: Six healthy participants were recruited for this study and only their dominant leg was tested. The subjects were tested under five conditions of vibration frequencies with constant amplitude: 0 Hz (no vibration), 30 Hz, 60 Hz, and 90 Hz, and the vibration amplitude was 10 mm for all frequency conditions. The vibration was applied to the rectus femoris (RF). The subjects were then instructed to maintain a steady-state isometric knee joint torque (100 Nm) for the first 6 s. After the steady-state torque production, the subjects were required to produce isometric knee joint torque by leg extension as hard as possible with a start signal within the next 3 s. The vibration was applied for ~4 s starting from 1 s before initiation of the change in the steady-state knee joint torque. Results: The results showed that the maximum voluntary torque (MVT) of the knee joint increased with the vibration frequencies. On average, the MVTs were 756.47 Nm for 0 Hz (no vibration) and 809.61 Nm for 90 Hz. There was a significant positive correlation (r = 0.71) between the MVTs and integrated electromyograms (iEMGs). Further, the co-contraction indices (CCIs) were computed, which represent the ratio of the iEMGs of the antagonist muscle to the iEMGs of all involved muscles. There was a significant negative correlation (r = 0.62) between the CCIs and MVTs, which was accompanied by a significant positive correlation (r = 0.69) between the iEMGs of the vibrated muscle (RF). There was no significant correlation between the MVTs and iEMGs of the antagonist muscle. Conclusion: The results of this study suggest that the short-term vibration on the muscle increases the level of muscle activation possibly owing to the increased Ia afferent activities, which enhances the muscle force generation capability.

• 한국운동역학회지
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• 제19권4호
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• pp.689-696
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• 2009

이 연구는 여성노인의 낙상 예방을 위하여 요부안정화운동을 실시하고 요부 등척성 근력, 복횡근과 다열근의 근두께, 자세안정성의 변화를 측정하였다. 대상자는 광주광역시에 소재한 요양원에서 여성노인 21명을 대상으로 8주간 운동 후 요부 등척성 근력, 복횡근과 다열근의 근두께, 자세안정성을 비교하였다. 요부 등척성 근력은 페가수스 근력 측정장치(3D Pegasus system, Germany), 복횡근과 다열근의 근두께는 초음파영상 계측장치(Sonoace 6000C, Korea), 자세안정성은 BBS 균형측정장치(Biodex Balance System SD, USA)로 측정하고 분석하였다. 요부 등척성 근력 중 굴곡, 신전, 좌회전과 복횡근 이완(횡)두께는 운동 전보다 운동 후에 통계학적으로 유의하게 증가하였으며, 자세안정성변화에서 전체 좌우 전후균형지수 모두 운동 후 통계학적으로 유의하게 감소하였다. 요부안정화운동이 근력 및 자세안정성에 영향을 미쳐 여성노인의 낙상 예방에 효과적이다 라는 결론을 얻었다.

• 대한통합의학회지
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• 제10권2호
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• pp.177-185
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• 2022

Purpose : The purpose of this study was to compare the effect of additional isometric contraction of trunk, shoulder, and hip muscles during abdominal crunch exercise on abdominal muscle thickness and to identify the most effective intervention for core muscle activation. Methods : This study was conducted on 22 healthy male adults. Subjects performed three types of crunch exercises (abdominal crunches accompanied by internal and external isometric rotation of the hip, horizontal shoulder adduction and abduction, and rotation of the trunk). The thickness of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) were evaluated using ultrasonography. The collected data used one-way repeated ANOVA statistics. Wilcoxon signed-rank test of nonparametric statistics was used for post-test analysis. Results : The IO thickness was significantly lower than general abdominal crunch when shoulder adduction was added (p<.05). The crunch with shoulder abduction, hip external rotation, and ipsilateral trunk rotation was significantly higher than the abdominal crunch (p<.05). The EO thickness was significantly greater in the crunch with hip external rotation than in the abdominal crunch (p<.05). Conclusion : The level of contraction in abdominal muscles appears to vary when isometric contractions of the trunk, shoulder, and hip muscles are added to the abdominal crunch exercise. Therefore, the use of isometric contractions of other joints to selectively induce contraction of the abdominal muscles may be considered.

• 한국전문물리치료학회지
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• 제19권3호
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• pp.11-19
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• 2012

This study aimed to investigate whether isometric lower limb exercise can activate contralateral trunk muscles and whether the magnitude of muscle activation is related to lower limb movement in sitting. This study included 25 healthy young subjects (20 males and 5 females). The magnitude of trunk muscle activation was measured using surface electromyography (EMG) during hip flexion, extension, adduction, and abduction, and a significant difference was observed in the activation levels of trunk muscles among the tests (p<.01). The EMG activity of the multifidus (MF) and erector spinae (ES) muscles on the contralateral side were significantly greater during hip extension. However, the activation levels of the contralateral internal oblique (IO) and rectus abdominis (RA) muscles were greatest during hip flexion. The MF : ES EMG ratio was significantly greater during hip isometric during hip isometric flexion and abduction compared to hip extension and adduction. There was no significantly difference in the IO : RA ratio during the isometric contractions toward different directions. These findings indicate that isometric lower limb exercise can elicit trunk muscle contraction on the contralateral side and may therefore be helped for developing contralateral trunk muscle strength in individuals undergoing rehabilitation.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.815-827
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• 2014

본 연구는 복근의 정적 지구력 평가 도구로서의 등척성 버티기 방법의 타당성을 검증하고 최적의 적용 각도를 결정해내기 위해 수행되었다. 92명(남 68명, 여 24명)의 피험자가 자발적으로 실험에 참여하여 다음과 같은 결과를 얻었다. 유산소 역량과 근지구력 역량 사이의 상관성은 남성에서보다 여성에게서 더 높게 나타났으며 등척성 버티기의 수행 시간과 윗몸일으키기의 반복 횟수 사이에 정적인 상관관계를 나타냈다. 또한 40도의 경사도를 적용 시 30도 및 50도와 비교해 근지구력과의 가장 높은 상관성을 나타냈다. 이와 같은 결과를 통해 복근지구력의 평가 도구로서의 등척성 버티기 방법이 요부의 잠재적 상해 위험을 지닌 것으로 보고되고 있는 윗몸일으키기 방법을 대체할 수 있는 대안으로 사용될 수 있으며 적용 시 40도의 각도를 적용하는 것이 적절하다는 결론을 내릴 수 있었다. 서로 다른 연령 및 체력 상태에 따른 최적의 적용 각도에 대해서는 후속 연구를 통해 밝혀져야 할 것이다.

• PNF and Movement
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• 제17권3호
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• pp.487-497
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• 2019

Purpose: This tutorial review investigated the effect of prior fatigue and passive stretches on eccentric contraction-induced muscle injuries, as well as the underlying mechanisms of eccentric contraction-related injuries. Methods: Contraction-induced muscle damage is the most common disabling problem in sports and routines. The mechanisms underlying the pathology and prevention of muscle damage lessened by prior fatigue or stretches are critical in assessing musculoskeletal injuries. Even though there are treatments to reduce eccentric contraction-induced muscle injuries, fatigue negatively influences them. Therefore, we reviewed previous studies on eccentric contraction-induced muscle injuries with prior treatments using the MEDLINE and PubMed databases. Results: Prior passive stretching had a preventative and therapeutic effect, but prior lengthening contractions did not. On the other hand, prior isometric contractions involving relatively small forces may not provide a sufficient stimulus to induce protection. As a result, high force isometric contractions may be necessary. The studies supported the positive effects of prior fatigue, concluding that it was a factor in determining the amount of damage caused by eccentric exercise. This was due to a reduction in force and increased temperature. Studies that did not support the positive effects of prior fatigue concluded that a shift in optimal length to a longer length and reduced energy absorption during lengthening are evidence that fatigue is not related to muscle injuries induced by lengthening. Conclusion: The variability of the experiment models, conditions, muscles, and treatment methods make it necessary to interpret the conditions of previous studies carefully and draw conclusions without making direct comparisons. Thus, additional studies should be carefully conducted to investigate the positive effect of fatigue on lengthening.

• 대한정형도수물리치료학회지
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• 제11권1호
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• pp.11-28
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• 2005

Spasticity has been defined as "a motor disorder characterized by a velocity-dependent increased in tonic stretch reflexes with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex, as one components of the upper motorneuron syndrome". Spasticity is one of the common symptoms of stroke patients and frequently interferes with the motor functions such as gait, posture and activities of daily living. Therefore, its management is becoming a major issue in physical therapy. The purpose of this study was to determined the effects of reciprocal inhibition by isometric contraction of pre-tibia muscle on spasticity in hemiplegic patients through Hoffmann reflex. The subjects were consisted 45 patients who had hemiplegia due to stroke. All subjects randomly assigned to 3 group: manual reciprocal inhibition program group(manual group), neuromuscular electrical stimulation group(NMES group) and control group. The manual group received voluntary isometric contraction of pre-tibia muscle. The NMES group received neuromuscular electrical stimulation on tibialis anterior. The control group was not received any therapeutic intervention. Before and after experiments, Hoffmann reflex, M-wave and Modified Ashworth scale was measure in all patients. The data of 30 patients who complete experimental course were statistically analysed. Modified Ashworth scale were significantly decreased after experiment in manual group(p<.01). The Hmax/Mmax ratios were significantly decreased after experiment in manual group(p<.o1). There were no statistical difference between pre-test and post-test with modified Ashworth scale in NMES group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in NMES group(p>.01). There were no statistical difference between pre-test and post-test with modified Ashworth scale in control group(p>.01). There were no statistical difference between pre-test and post-test with Hmax/Mmax ratios in control group(p>.01). The present results revealed that reciprocal inhibition which produced by voluntary isometric contraction of pre-tibia muscle can be reduce spasticity of gastrocnemius. Therefore, reciprocal inhibition is useful to improve functional activities in hemiplegic patient. Further study should be done to analyse the effects of intervention duration of reciprocal inhibition, appropriate muscle contraction, optimal time to apply the reciprocal inhibition in more long period.

• 약학회지
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• 제56권3호
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• pp.180-185
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• 2012

The aim of present study was to investigate the possible influence and related mechanism of alcohol on the arterial contraction. Vascular contraction involves the activation of thick or thin filament pathway. However, there are no reports addressing the question whether this pathway is involved in alcohol-induced regulation. We hypothesized that alcohol plays a role in vascular contraction evoked by a vasoconstrictor in rat aortae regardless of endothelial function. Denuded arterial rings from male rats were used and isometric contractions were recorded using a computerized data acquisition system. Interestingly, alcohol at a low concentration (3% v/v) inhibited thromboxane $A_2$ or phorbol ester-induced contraction with endothelial function but at a high concentration (10%) didn't inhibit and rather increased the contraction in the denuded muscle. Therefore, alcohol at a low concentration decreases the contraction and alcohol at a high concentration increases the contraction suggesting that additional pathways different from endothelial nitric oxide synthesis might be involved in the regulation of contractility. In conclusion, alcohol has some effect on the regulation of contractility regardless of endothelial function.

• 한국전문물리치료학회지
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• 제31권2호
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• pp.114-122
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• 2024

Background: The peroneus longus (PL) and peroneus brevis (PB) function as the primary muscles of eversion, a movement closely associated with tibial external rotation for ankle mortise stability. Ankle motion and tibial rotation vary based on different ankle and knee positions. Objects: This study aimed to investigate the PL, PB, and biceps femoris (BF) muscle activation and eversion strength during side-lying isometric eversion exercise based on different ankle positions (neutral [N] and plantarflexion [PF]) and knee positions (90° flexion [KF] and extension [KE]). Methods: Thirty healthy adults with an Ankle Joint Functional Assessment Tool score of ≥ 22 were recruited (mean age = 24.8 ± 3.1 years). Maximal isometric eversion strength and submaximal muscle activation of the PL, PB and BF were measured during isometric eversion exercise in side-lying. A 2 × 2 repeated measures analysis of variance was performed to investigate differences in muscle activation and strength. Results: The PL and PB muscle activation showed significant main effects with the knee and ankle positions (p < 0.05); activation was greater in the KE and PF positions than in the KF and N positions. The BF muscle activation showed a significant interaction effect with knee and ankle positions, which was greater in knee extension and ankle plantarflexed (KEPF) position than in knee flexion and ankle plantarflexed (KFPF) position (p < 0.05). Eversion strength showed a significant main effect only in ankle position (p < 0.05) and was greater in the N position than in the PF position. Conclusion: The results of this study indicate that the KEPF position can be recommended to facilitate contraction of the PL and PB during side-lying eversion exercise. Furthermore, the effects of the knee-ankle positions should be considered for measuring ankle eversion strength and implementing the isometric submaximal side-lying eversion exercise.