• 한국의류산업학회지
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• 제11권6호
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• pp.911-917
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• 2009

The purpose of this study was to investigate muscle activity of the lower limbs when walking in jeans in order to obtain basic information for development of new jeans patterns with excellent movement adaptability. Using three types of jeans (basic, medium, and slim) with different ease on hip, knee circumference, and crotch length, and two different types of shoes, Electromyogram (EMG) of the lower limbs muscle was measured for four healthy subjects walking on treadmills and stairs. EMG of vastus lateralis, semitendinous, tibialis anterior and medial head of gastrocnemius muscles was measured. The muscle activity was assessed in RMS (Root Mean Square) value of the EMG. On the treadmill in sneakers, only the vastus lateralis muscle showed a significant difference in RMS value depending on patterns. Basic and medium jeans allowed higher muscle activity than trunks of slim jeans did. On the treadmill in high heels and slim jeans, the RMS values of all muscles were significantly smaller than in basic jeans, whereas no significant differences were shown while in trunks or medium jeans. On the stairs either in sneakers or in high heels, no significant differences were shown between all muscle activities for all types of jeans. On the treadmill, greater fatigue was induced in all muscles from walking in high heels than in sneakers for all jeans patterns. When walking on the stairs wearing either type of shoes, however, the effect of jeans pattern on muscle activities was different from muscle to muscle.

• 대한물리의학회지
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• 제7권2호
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• pp.173-182
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• 2012

Purpose : This study was investigated the effect of lower extremity muscle activity during open kinetic chain exercise (OKC) and closed kinetic exercise (CKC) in normal young adults. Methods : The participants were consisted of forty-one. All subjects were randomly assigned to two groups of open kinetic chain exercise group (n=21) and closed kinetic chain exercise group(n=20). It was perform 3 sets, 3 times per week for 6 weeks both open kinetic chain exercise group and closed kinetic chain exercise group. Subjects were assessed for each subject took pre-test, post-test in 2 weeks, post-test in 4 weeks, post-test in 6 weeks measurement the surface EMG data for vastus medialis and lateralis, lateral and medial hamstring, lateral and medial gastrocnemius, tibialis anterior. Results : The vastus medialis and lateralis muscle activity was significantly increased within the intervention period both group(p<.05). The lateral and medial part of hamstring muscle activity was significantly increased with in the intervention period(p<.05). The tibialis anterior muscle activity of open kinetic chain exercise group and closed kinetic chain exercise group was significantly increased in the intervention period(p<.05). The lateral and medial part of gastrocnemius muscle activity of open kinetic chain exercise group and closed kinetic chain exercise group was significantly increased with in the intervention period(p<.05). Conclusion : It was found that both open kinetic chain exercise and closed kinetic chain exercise was significantly increased muscle activity. Further studies are needed to analyzed long term effects and subjects resulting from these changed. these exercises can be selectively adapted not only as treatment exercise for patients but also as preventive exercise for normal person to improve balancing ability by conducting proper amount of exercise for each individual's condition and stage.

• 한국융합학회논문지
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• 제9권10호
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• pp.371-376
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• 2018

본 연구는 전신진동 자극시 스쿼트의 형태에 따른 하지근육의 근활성 효과의 차이를 분석함으로써 전신진동운동의 효과를 규명하고 효율적인 운동을 위한 과학적 근거를 제시하는데 그 목적이 있다. 본 연구는 정형외과적 질환이 없는 건강한 20대 남성 10명을 대상으로 똑바로 선자세, 슬관절을 90도, 120도 굴곡시킨 일반적인 스쿼트 자세와 뒷꿈치를 들어 올린 혼합 스쿼트 자세의 진동자극 시 근활성도를 측정하였다. 근활성도는 외측비복근, 전경골근, 외측광근, 대퇴이두근에 근전도 전극을 부착한 후 RMS를 구하여 비교하였으며 진동 자극의 강도는 각 자세에서 볼륨 50, 80, 주파수 10, 25, 40Hz를 혼합하여 적용하였다. 분석 결과 외측비복근과 전경골근 외측광근에서 자세별 근활성도의 차이가 나타났고 뒷꿈치를 들어올린 자세에서 근활성 효과가 높음을 확인할 수 있었다. 이와 같은 결과는 전신진동 자극 시 스쿼트 자세와 강도에 따라 근활성 효과에 차이가 있으며, 운동의 효율을 극대화하기 위하여 목표 근육에 따라 다양한 자세와 강도가 적용되어야 함을 의미한다.

• 대한물리의학회지
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• 제9권3호
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• pp.249-253
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• 2014

PURPOSE: This study intends to examine the effects of change of anatomical position of the ankle joint in open kinematic chain, an appropriate position for selective muscle training, on vastus lateralis obliques, rectus femoris, vastus medilais obliques, and rectus abdominalis muscle activation and to present an effective method of muscle training for patients and normal people. METHODS: The participants of this study were Korean healthy adult in their 20s. The 8 channel surface electromyography was used to measure muscle activation while the subjects raised their legs under each condition. Under each condition, while the subjects raised the leg to hip joint flexion at $60^{\circ}$ along the arch. RESULTS: The analysis result of muscle activation by each section and position during leg rising. There were significant differences. CONCLUSION: For independent strengthening of each muscle, muscle activation was measured according to leg raising angles and the result differed according to each section and position. If this study result is applied to muscle training for patients who need selective muscle training, more effective muscle strengthening will be made possible.

• 대한통합의학회지
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• 제5권3호
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• pp.57-61
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• 2017

Purpose : The purpose of study was to find out the environmental risk factor that can be easily occurred imbalance muscle activities according to direction for using the ramp during one legged standing. Method : The subjects were 20 normal adults with a mean age of $23.15{\pm}2.14years$ and a Body Mmass Index (BMI) of $22.74{\pm}1.07$. Participants were measured muscle activities on vastus medialis, vastus lateralis, tibialis anterior, peroneus longus during one legged stance at four conditions ramp (down ramp, up ramp, medial ramp, lateral ramp). The statistical analyses were performed using IBM SPSS(Ver. 23) and p-value less than .05 were considered statistically significant for all cases. Result : In this study, the activity of the lower extremity muscle and the ratio of the vastus medial and lateral muscles according to the direction of use of the ramp were investigated. The changes in the muscle activity of the lower limbs along the direction of the ramp were significantly different between the vastus medial muscle and the peroneus longus muscle. Conclusion : For a short time on a ramp or a pedestrian crossing, a clerk in a ramp can move or stand by placing the lower limbs in various directions, but if performed in consideration of the individual's disease characteristics or unstable foot position, It is thought that there will be an effect to prevent on the ankle and knee unstability.

• 대한물리의학회지
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• 제5권4호
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• pp.605-613
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• 2010

Purpose : The purpose of this study was to investigate the VMO/VL ratio and onset timing using EMG biofeedback training over a 5-day period. Methods : Twenty-one healthy female college students with no known right knee musculoskeletal dysfunction were recruited this study. Muscle activity was measured by surface electromyography(Myosystem 1400A, Noraxon Inc., U.S.A). Statistical analysis was used two-way repeated ANOVA to know difference between the vastus lateralis and vastus medialis oblique onset timing differences, VMO/VL ratio. Results : Biofeedback training group significantly improved VMO/VL ratio and EMG activity of the vastus medialis oblique after intervention. Conclusion : These result indicate that biofeedback training on the vastus medialis oblique has effect on the VMO/VL ratio. EMG biofeedback can be recommended for the facilitation of VMO muscular recruitment.

• PNF and Movement
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• 제15권3호
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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.

• 한국운동역학회지
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• 제14권3호
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• pp.271-284
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• 2004

The purpose of this study was to analyse the EMG activity of selected muscles with balance taping treatment and blood fatigue makers which accumulated during exercise of progressive maximal intensity. Ten male college students who did not experience any cardiovascular and musculo-skeletal disease were participated in this study. Balance taping were applied to rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinous, semimembranous, and around knee joint. Isokinetic knee joint flexion/extension force, EMG activity, lactate and ammonia as blood fatigue makers during progressive maximal intensity exercise were measured for with/without applying balance taping. The results indicated that although flexion force of total work at $60^{\circ}/sec$ with taping was increased applied taping did not affect to the aerobic exercise ability parameters. Lactate level as blood fatigue makers during progressive maximal intensity exercise after taping was decreased but the ammonia level did not change with same treatment. In isokinetic knee joint test at the angular velocity of $60^{\circ}/sec$, $180^{\circ}/sec$, and $240^{\circ}/sec$ the taping treatment did not affect to any selected muscle EMG activities except maximal EMG of vastus lateralis at $240^{\circ}/sec$.

• 한국운동역학회지
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• 제22권4호
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• pp.413-419
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• 2012

The purpose of this study was to investigate the effects of increased saddle height on the length and activity pattern of vastus lateralis (VL) and biceps femoris (BF) muscle. To compare the effects of increased saddle height, Preferred (self-selected height of subject) and High saddle height (approximately 5% higher saddle height than self-selected) were used. Seven elite cyclists (career: $16.1{\pm}8.5years$) participated in 3 min. sub-maximal pedaling tests under the same cadence (90 RPM) and pedaling power (150 W). Hip and knee joint angles, and the length and activity of VL and BF were compared by measuring 3D motion and electromyography (EMG) data. Results showed that there were significant differences in peak extension timing of the hip joint angle and the range of motion of the hip and knee joint between different saddle heights. Although there were significant differences in muscle length of both muscles with increasing saddle height, the timing and amount of muscle activity differed only at the BF. These findings suggest that the timing and amount of bi-articular muscle activity (i.e. BF) can be altered by changing the saddle height. For practically applying these results, further study is necessary to evaluate the effects of various cadence and the pedaling power with various saddle heights.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.345-353
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• 2018

This study suggested a new EMG-signal-based evaluation method for knee rehabilitation that provides not only fragmentary information like muscle power but also in-depth information like muscle fatigue in the field of rehabilitation which it has not been applied to. In our experiment, nine healthy subjects performed straight leg raise exercises which are widely performed for knee rehabilitation. During the exercises, we recorded the joint angle of the leg and EMG signals from four prime movers of the leg: rectus femoris (RFM), vastus lateralis, vastus medialis, and biceps femoris (BFLH). We extracted two parameters to estimate muscle fatigue from the EMG signals, the zero-crossing rate (ZCR) and amplitude of muscle tension (AMT) that can quantitatively assess muscle fatigue from EMG signals. We found a decrease in the ZCR for the RFM and the BFLH in the muscle fatigue condition for most of the subjects. Also, we found increases in the AMT for the RFM and the BFLH. Based on the results, we quantitatively confirmed that in the state of muscle fatigue, the ZCR shows a decreasing trend whereas the AMT shows an increasing trend. Our results show that both the ZCR and AMT are useful parameters for characterizing the EMG signals in the muscle fatigue condition. In addition, our proposed methods are expected to be useful for developing a navigation system for knee rehabilitation exercises by evaluating the two parameters in two-dimensional parameter space.