• 대한의용생체공학회:의공학회지
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• 제32권1호
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• pp.1-6
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• 2011

An active training system has been developed to assist the upper extremity function in patients with spasticity. We also evaluated the performance of the developed assistive system in five normal subjects and one hemiplegic patient. The maximum voluntary contraction (MVC) tests for biceps brachii and triceps brachii were performed and the relationship between linear enveloped EMG signal and the elbow joint torque was found. In order to implement an active training, our system was designed to allow isokinetic movement only when the subject generates elbow joint motion larger than the pre-fixed threshold level. The proposed EMG-feedback control method could provide active exercises, resulting in better rehabilitation protocol for spastic patients.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1492-1495
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• 2008

As a prerequisite of developing muscle biofeedback system which can simulate analogous isokinetic exercise, the purpose of this study was to study the effects of frequency and amplitude of whole-body vibration on the difference in sEMG on lower extremities during leg press exercise with/without vibration. The amplitude of vibration was set to 20, 50, 80 and the frequency of vibration was set to 10, 20, 30, and 50 Hz. EMG were measured at Vastus lateralis muscle and Vastus medialis muscle. MP100 EMG module(BIOPAC system Inc., USA) was used for EMG measurement. The result showed that the combination of frequency of 30Hz and amplitude of 50 had more activated EMG than other combination with relatively small work load (30kg). It is necessary to experiment the frequency between 20 and 40Hz in detail, and to normalize sEMG using maximal voluntary contraction (MVC).

• Korean Journal of Acupuncture
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• 제28권4호
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• pp.59-66
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• 2011

Objectives : This study is aimed to evaluate and objectify the therapeutic effect of moxibustion on muscle fatigue recovery. Methods : To evaluate the therapeutic effect on the muscle fatigue recovery, we compared the fatigue recovery of two groups (non-stimulation group and moxibustion group) by analyzing the EMG and peak torque after strenuous knee exercise of isokinetic contraction. Results : The median frequency (MF) of the moxibustion group was recovered faster than that of the non-stimulation group. However, the peak torques of both groups were not restored until after 20 minutes. Nevertheless, the moxibustion group's peak torque was regained higher than that of the non-stimulation group. Conclusions : We confirmed the therapeutic effect of moxibustion and found that the moxibustion can used as prevention method for musculoskeletal disease.

• 한국운동역학회지
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• 제23권2호
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• pp.149-157
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• 2013

In the present study, we aimed to elucidate how muscle strength and activity are affected by movement pattern(bilateral [BLM] & unilateral movement [ULM]) and movement velocity($0^{\circ}$/s, $60^{\circ}$/s, $120^{\circ}$/s) at maximum effort, and to elucidate the relationship between a left/right asymmetry and bilateral deficit. A total of 18 healthy males participated in the study. Each participant performed maximum knee extension bilaterally and unilaterally while the EMG and moment were recorded, and then the relationships between the asymmetry and bilateral deficit were analyzed. The peak moments for the isokinetic motion at $60^{\circ}$/s and $120^{\circ}$/s and overall muscle activities of lower extremity were significantly reduced for the BLM in comparison to the ULM. And though the asymmetry in ULM were maintained during BLM at all velocities, the bilateral deficits at the velocity of $0^{\circ}\acute{y}$/s and $120^{\circ}\acute{y}$/s were significantly correlated with increased asymmetries of muscle strength in ULM. In conclusion, the reduction in the muscle strength exhibited in bilateral knee extension was shown to arise partially from a reduction in muscle activity, and left/right asymmetry was found to be associated with mechanical reduction in bilateral movement. These findings suggest that training aimed at increasing muscle strength must involve methods and strategies intended to reduce left/right asymmetry.

• The Journal of Korean Physical Therapy
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• 제31권4호
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• pp.161-168
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• 2019

Most athletes with anterior cruciate ligament (ACL) ruptures undergo a surgical ACL reconstruction (ACLR) and rehabilitation. On the other hand, controversy still exists because neither a reconstruction nor rehabilitation have been proven to be superior in the management of ACL injury. This study reviewed the success rates of interventions to provide recommendations for the optimal management after an ACL injury. One of the most important considerations after an ACL injury is the timing and type of intervention. At the early stages, which involve the loss of volume and strength of quadriceps femoral muscle, weight bearing (closed kinetic chain) exercises with pain management followed by high velocity resistance exercises in an open kinetic chain environment are recommended to improve the quadriceps function. After that, it is important to apply intensive isokinetic exercise with a lower extension rate. In this case, it is important to apply overload to the muscles and to simultaneously lead the co-contraction of the hamstrings. Standards are essential because the timing and type of interventions are crucial to prevent re-injury and complications, such as osteoarthritis, as well as to confirm the successful outcome of the treatment. Different interventions recommended for ACL damage have yet to reach consensus. Further studies will be needed to observe the effects of the intervention through multidisciplinary approaches.

• 한국체육학회지인문사회과학편
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• 제54권5호
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• pp.769-780
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• 2015

이 연구는 고령자의 근육수축양식 및 손상정도에 따른 염증물질, 면역적격세포 및 골수유래 전구세포의 변화를 검증하는데 그 목적이 있다. 연구대상은 최근 6개월간 저항성운동 프로그램을 실시하지 않은 65세 이상의 고령자 20명을 신장성운동 집단(ECC, n=10)과 단축성운동 집단(CON, n=10)으로 분류하였다. 모든 피험자는 팔꿈치 굽힘근의 1차 신장성운동(ECC 1) 및 단축성운동(CON)을 실시하였고, ECC는 4주후에 재차 2차 신장성운동(ECC 2)을 6회 10세트, 세트 사이에 2분의 휴식시간을 적용하여 실시하였다. 골격근손상 지표(ROM, VAS, CK), 염증물질(TNF-α, IL-1, IL-6), 면역적격세포(CD3+, CD4+, CD8+, CD19+), 골수유래 전구세포(CD34+) 및 백혈구수는 운동전, 운동 직후, 운동 시기의 2, 24, 48, 72 및 96시간 후에 각각 측정하였다. 주요결과는 다음과 같다. 고령자의 골격근손상 지표(ROM, VAS)는 CON(근육수축양식) 및 ECC 2(손상정도)와 각각 비교해서 ECC 1에서 손상이 크게 증가하였다(p<.05). IL-6 및 TNF-α는 CON 및 ECC 2와 각각 비교해서 ECC 1의 24, 48 및 72시간 후에 유의하게 높게 나타났다(p<.05). 호중구수는 CON 및 ECC 2와 각각 비교해서 ECC 1의 2시간 후에 유의하게 높게 나타났다(p<.05). 이 연구에서는 고령자에서도 근육수축양식은 단축성운동보다 신장성운동에서, 또한 손상정도는 2차 신장성운동보다 1차 신장성운동에서 보다 크게 손상이 발생하였다는 사실을 확인하였다. 특히 IL-6와 TNF-α 및 호중구수는 근손상 정도와 밀접한 관련성이 있다는 것이 시사되었다.

• 로봇학회논문지
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• 제5권1호
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• pp.48-54
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• 2010

Ankle-foot orthosis with a pneumatic rubber actuator, which is intended for the assistance and the enhancement of ankle muscular activities was developed. In this study, the effectiveness of the system was investigated during plantarflexion motion of ankle joint. To find a effectiveness of the system, the subjects performed maximal voluntary isokinetic plantarflexion contraction on a Biodex-dynamometer. Plantarfexion torque of the ankle joint is assisted by subject's soleus muscle that is generated when ankle joint do plantarflexion motion. We used the muscular stiffness signal of a soleus muscle for feedback control of ankle-foot orthosis as physiological signal. For measurement of this signal, we made the muscular stiffness force sensor. We compared a muscular stiffness force of a soleus muscle between with feedback control and without it and a maximal plantarflexion torque between not wearing a ankle-foot orthosis, without feedback control wearing it and with feedback control wearing it in each ten elderly adults. The experimental result showed that a muscular stiffness force of a soleus muscle with feedback control was reduced and plantarflexion torque of an ankle joint only wearing ankle-foot orthosis was reduced but a plantarflexion torque with feedback control was increased. The amount of a increasing with feedback control is more higher than the amount of a decreasing only wearing it. Therefore, we confirmed the effectiveness of the developed ankle-foot orthosis with feedback control.

• 대한물리치료과학회지
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• 제9권3호
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• pp.77-87
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• 2002

The purpose of this study was to compare the changes of muscle activities in deltoid with those in supraspinatus using electromyography(EMG) while subjects abducted their shoulder to different angles with different resistance. Methods : 20 volunteers who were comprised of 10 males(mean age: $21.2{\pm}2.0$) and 10 females(mean age: $20.2{\pm}1.6$) were collected. Surface electrodes were attached on deltoid and supraspinatus muscle for recording. Each reference electrode was located 3 cm to the each recording electrode. Muscle action potentials were recorded with changing the angle of shoulder abduction, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. This procedure was repeated with different resistance 0 pound, 2 pounds, 4.5pounds. The angle of shoulder abduction was determined by clinical goniometer. SPSS(Statistical Program for Social Science)/WIN 10.0 was used for statistics. Analysis included ANOVA, T-test. Results : The following results were obtained in this study. 1. There was significant differences during isometric shoulder abduction $30^{\circ}$, $60^{\circ}$, $90^{\circ}$ comparing muscle activity in deltoid and supraspinatus muscles at 0 pound, 2pound, 4.5pound resistance(p<0.05). 2. There was no useful significant in the deltoid and supraspinatus muscles activity EMG compared by physical condition. 3. Their was significant in the deltoid EMG compared by gender t=-5.41, P<0.01, but no difference in the supraspinatus EMG(P=0.333 >a=0.05). Conclusions: There are many previous studies on influence of shoulder angles and speeds of muscle activity. However most of them placed the focus on isotonic or isokinetic exercise, or shoulder function. But this study was done during isometric exercise, which is better for early assessment and treatment for injured patients. There is strong relationship between the shoulder angle with resistance in deltoid supraspinatus muscle activity. We conclude that it is important to apply isometric shoulder abduction exercise with correct angle and resistance especially in early stage.

• International Journal of Contents
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• 제6권1호
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• pp.1-5
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• 2010

Kinesio Taping (KT) is widely used by physical therapists to treat a variety of neuromusculoskeletal disorders. In this study it was examined whether or not KT has an effect on the peak torque and muscle activity of the quadriceps muscles in healthy subjects. KT was applied to the anterior thigh and tibia of fifteen healthy males (mean age, 25.42${\pm}$1.38 years, mean body height 178.58${\pm}$3.03 cm, mean body weight 71.58${\pm}$6.42 kg) who have no problem within past 2 months. The quadriceps peak torque was assessed using an isokinetic dynamometer while the mean data of muscle activity was measured by surface electromyography (EMG). The maximal voluntary isometric contraction was carried out on all subjects at $0^{\circ}$, $30^{\circ}$ and $60^{\circ}$ before, during, and after KT. There were no significant differences in the peak torque and mean data of quadriceps muscle(vastus lateralis, rectus femoris, and vastus medialis oblique) activity at $0^{\circ}$, $30^{\circ}$ and $60^{\circ}$ before, during and after application of KT (p>.05). From this study it could be concluded that the application of KT to the anterior thigh and tibia doesn't affect the peak torque and the muscle activity.

• The Journal of Korean Physical Therapy
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• 제18권6호
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• pp.1-11
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• 2006

연구목적: 이 연구는 피부표면 냉각이 생체내의 건구조 점탄성 특성에 미치는 영향을 비교하였다. 방법: 7명의 남성 실험 대상자는 족저굴곡 운동을 10회$\times$10set, 60초 간격으로 최대 수의적 수축을 6초간 각각 실시하였다. 각 측정 전후에 내측 비복근(MG)의 건과 건막의 신장은 초음파 검사법에 의하여 직접 측정되었다(건 장력과 건 신장의 관계로 평가 되었다). 건 횡단면적과 족 관절 모멘트 암은 자기공명영상법(MRI)으로부터 얻어졌다. 건 장력은 관절 모멘트와 건 모멘트 암으로 계산되었다. 또한 스트레스는 횡단면적영역(CSA)을 힘으로 나눔으로써 얻어졌다. 스트레인은 건의 길이로 표준화된 치환으로부터 측정되었다. 결과: 냉각 후에 건 장력은, 비냉각 보다 냉각한 측이 유의하게 높았다. 스티프네스는 비냉각 조건 보다 냉각 조건하에서 높은 유의수준을 나타냈다. 최대의 스트레인과 스트레스는 냉각조건하에서 $7.4{\pm}0.7$와 $36.4{\pm}1.8$ MPa을 나타냈고, 비냉각 조건하가 $7.8{\pm}8.5$ 와 $31.8{\pm}1.1$ MPa (p<0.05)을 나타냈다. 결론: 이 연구의 결과는 피부표면 냉각으로 인해 인간의 근지구력이 건 스티프네스와 탄성률을 증가시키는 것을 시사하는 연구라 하겠다. 피부 표면 냉각으로 인한 근지구력의 개선이 근과 건에 직접적인 영향을 미침을 나타내주고 있다.