• Bulletin of the Korean Chemical Society
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• 제24권9호
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• pp.1293-1302
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• 2003

Rate constants at various temperatures and activation parameters are reported for solvolyses of acyl chlorides (RCOCl), with R = Me, Et, i-Pr, t-Bu, cyclopentylmethyl, benzyl, thiophenylmethyl, 2-phenylethyl, diphenylmethyl, and phenylthiomethyl in 100% ethanol, 100% 2,2,2-trifluoroethanol (TFE), 80% v/v ethanol/ water and 97% w/w TFE/water. Additional rate constants for solvolyses with R = Me, t-Bu, and $PhCH_2$ are reported for TFE/water and TFE/ethanol mixtures, and for solvolyses with R = t-Bu, and PhCH2 are reported for 1,1,1,3,3,3-hexafluoropropan-2-ol/water mixtures, as well as selected kinetic solvent isotope effects (MeOH/MeOD and TFE). Taft plots show that electron withdrawing groups (EWG) decrease reactivity significantly in TFE, but increase reactivity slightly in ethanol. Correlation of solvent effects using the extended Grunwald-Winstein (GW) equation shows an increasing sensitivity to solvent nucleophilicity for EWG. The effect of solvent stoichiometry in assumed third order reactions is evaluated for TFE/ethanol mixtures, which do not fit well in GW plots for R = Me, and t-Bu, and it is proposed that one molecule of TFE may have a specific role as electrophile; in contrast, reactions of substrates containing an EWG can be explained by third order reactions in which one molecule of solvent (ethanol or TFE) acts as a nucleophile, and a molecule of ethanol acts as a general base catalyst. Isokinetic relationships are also investigated.

• Physical Therapy Rehabilitation Science
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• 제9권2호
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• pp.113-119
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• 2020

Objective: The vibration device is one of the most commonly used warm-up devices not only for healthy athletes but also for healthy individuals. Therefore, this study aimed to investigate the immediate effects of local vibration on ankle plantar flexor muscle activation and peak torque in healthy adults. Design: One-group pretest-posttest design. Methods: This was a single-group study comprising a total of 36 (16 males and 20 females) participants. The average age of the 36 participants was 22.3 years. All the participants' concentric and eccentric peak torques of the gastrocnemius lateralis muscle were measured using an isokinetic device. Simultaneously, the participants' muscle activity was measured by surface electromyography. After the pre-experimental data were collected, the participants comfortably sat on the prepared chair with their hips and knees flexed to 90°. While in sitting position, local vibration was applied for 10 minutes using a 1:1 ratio intermittent pulsing mode device based on a previous study. Then, the post-experimental data were collected immediately after the local vibration by performing a similar process performed during the pre-experimental data collection. Results: The results showed a significant difference in muscle activity and eccentric peak torque (p<0.05). On the contrary, concentric peak torque values showed an insignificant difference with pre- and post-value. Conclusions: The results of this study demonstrated that local vibration can be possibly considered as one of the effective ways to increase ankle plantar flexor muscle activity and muscle performance, specifically the eccentric peak torque, in healthy adults.

• The Journal of Korean Physical Therapy
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• 제3권1호
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• pp.75-90
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• 1991

흰쥐 하퇴에 있어서 수령이 근섬유 조성에 미치는 영향을 규명하기 위하여 대조군 및 운동 실험군으로 모델을 설정하여 운동기간(4주 및 8주)에 따른 근섬유의 조성을 조직, 조직화학 및 형태측량법으로 분석한 결과 다음과 같은 실험결과를 얻었다. 1. 조직학적 연구에서는 대조군에 비하여 실험군에서 각 근섬유 사이와 근속 사이의 간격이 좁아졌으며 근초는 불규칙한 양상으로 관찰되었다. 2. 조직화학적 연구에서 NADH-TR반응 및 myosin ATPase 반응으로 적근, 중간근, 백근의 조성양상을 관찰한 결과 실험군에서 적근과 중간근의 분포가 많은 반면, 백근의 분포가 적어진 양상을 보였다. 3. 형태측량적 연구에서 전경골근 및 비복근 모두 대조군에 비해 실험군에서 적근과 중간근이 증가하였고, 백근과 결합조직의 양은 감소하였다.

• 한국입자에어로졸학회지
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• 제15권3호
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• pp.105-113
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• 2019

The exhaust emissions from coal-fired power plants have received much attention because coal-fired power plants are the one of the largest sources of particulate matter (PM) emissions in South Korea. To measure the PM10 and PM2.5, we developed the novel diluter which is comprised of ejector and porous tube in series. The dilution ratio must be defined to calculate particle concentrations of the sampled air as well as to probe match for the isokinetic sampling. For this reason, we verified the dilution ratio of the developed diluter by the flow rate, numerical solution, gas concentration and particle concentration. The ejector-supplied flow rates were 10-50 L/min and the porous tube-supplied flow rates were 30, 50 L/min in this study. All methods above showed similar dilution ratios to each other within 10 % error rate. The dilution ratio was confirmed by comparing mass concentrations before and after the dilution process.

• Clinics in Shoulder and Elbow
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• 제22권4호
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• pp.190-194
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• 2019

Background: The duration of immobilization after arthroscopic rotator cuff repair and the optimal time to commence rehabilitation are still the subject of ongoing debates. This study was undertaken to evaluate the functional outcome and rotator cuff healing status after arthroscopic rotator cuff repair by comparing early and delayed rehabilitation. Methods: Totally, 76 patients with small, medium, and large sized rotator cuff tears underwent arthroscopic repair using the suturebridge technique. In early rehabilitation group, 38 patients commenced passive range of motion at postoperative day 2 whereas 38 patients assigned to the delayed rehabilitation group commenced passive range of motion at postoperative week 3. At the end of the study period, clinical and functional evaluations (Constant score, the University of California, Los Angeles [UCLA] shoulder score) were carried out, subsequent to measuring the range of motion, visual analogue scale for pain, and isokinetic dynamometer test. Rotator cuff healing was confirmed by magnetic resonance imaging at least 6 months after surgery. Results: No significant difference was obtained in range of motion and visual analogue scale between both groups. Functional outcomes showed similar improvements in the Constant score (early: 67.0-88.0; delayed: 66.9-91.0; p<0.001) and the UCLA shoulder score (early: 20.3-32.3; delayed: 20.4-32.4; p<0.001). Furthermore, rotator cuff healing showed no significant differences between the groups (range, 6-15 months; average, 10.4 months). Conclusions: Delayed passive rehabilitation does not bring about superior outcomes. Therefore, early rehabilitation would be useful to help patients resume their daily lives.

• Annals of Rehabilitation Medicine
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• 제42권6호
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• pp.804-813
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• 2018

Objective To elucidate the effect of a 12-week horizontal vibration exercise (HVE) in chronic low back pain (CLBP) patients as compared to vertical vibration exercise (VVE). Methods Twenty-eight CLBP patients were randomly assigned to either the HVE or VVE group. All participants performed the exercise for 30 minutes each day, three times a week, for a total of 12 weeks. Altered pain and functional ability were evaluated using the visual analog scale (VAS) and Oswestry Disability Index (ODI), respectively. Changes in lumbar muscle strength, transverse abdominis (TrA) and multifidus muscle thicknesses, and standing balance were measured using an isokinetic dynamometer, ultrasonography, and balance parameters, respectively. These assessments were evaluated prior to treatment, 6 weeks and 12 weeks after the first treatment, and 4 weeks after the end of treatment (that is, 16 weeks after the first treatment). Results According to the repeated-measures analysis of variance, there were significant improvements with time on VAS, ODI, standing balance score, lumbar flexor, and extensor muscle strength (all p<0.001 in both groups) without any significant changes in TrA (p=0.153 in HVE, p=0.561 in VVE group) or multifidus (p=0.737 in HVE, p=0.380 in VVE group) muscle thickness. Further, there were no significant differences between groups according to time in any of the assessments. No adverse events were noticed during treatment in either group. Conclusion HVE is as effective as VVE in reducing pain, strengthening the lumbar muscle, and improving the balance and functional abilities of CLBP patients. Vibrational exercise increases muscle strength without inducing muscle hypertrophy.

• 디지털융복합연구
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• 제17권3호
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• pp.463-471
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• 2019

본 연구는 무릎 근력의 불균형이 백 스쿼트 시 인체 움직임의 제한 요인으로 작용하는지를 확인하는 것에 목적이 있다. 백 스쿼트 유경험자로 최근 2년간 부상이 없는 서울시 소재 S대학교 학생 8명을 연구 대상자로 선정하였다. Cybex 770으로 무릎관절의 등속성 근력을 측정한 후, 동측 주작용근과 대항근의 근력 불균형 정도와 좌 우 같은 근 군의 결손율에 따라 그룹을 나눈 후, 개인별 몸무게의 25%, 50%, 100%, 125%의 중량과 같은 바벨을 백 스쿼트로 들게 하였다. 무릎 굽힘 각도, 신체중심의 수직 변위, V-COP의 측정 구간 내 평균 위치로부터 매 순간 V-COP 까지의 거리 합 변인들에 대한 집단별 차이를 검증하기 위해 독립표본 T 검정을 실시하였다. 125%BW 조건에서 무릎관절 근력의 동측 불균형은 쭈그려 앉는 자세의 제한 요인으로, 좌 우측 폄 근력의 불균형은 평형성 유지의 제한 요인으로 작용하였다. 근력의 불균형이 인체 움직임의 제한 요인으로 작용할 수 있음을 확인하였으므로, 차후 임상에서는 근력 불균형에 대한 검사법과 함께 교정 및 재활 운동 방법 또한 발전시켜 나갈 필요가 있다.

• 한국전문물리치료학회지
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• 제28권4호
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• pp.256-265
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• 2021

Background: Individuals with scapular winging may have proprioceptive dysfunction which is important for motor control and causes shoulder instability. Reduced serratus anterior (SA) and lower trapezius (LT) muscle activity accompanied by over-active upper trapezius (UT), and pectoralis major (PM) may be contributing factors. Flexi-bar (FB) exercise may be used to increase joint position sense (JPS) and alter the target muscle activities. Objects: This study aimed to investigate the immediate effects of flexi-bar exercise prior to knee push-up plus (FPK) versus knee push-up plus (KPP) on JPS and muscle activity of SA, LT, UT, and PM in subjects with scapular winging. Methods: Eighteen subjects with scapular winging were recruited. JPS was investigated at baseline, after KPP and after FPK. Passive and active JPS errors were calculated by isokinetic equipment. Surface electromyography was used to record muscle activities during KPP and FPK. One-way repeated-measures analysis of variance and post hoc analyses were used to analyze the JPS error measured at baseline, after KPP and after FPK. Paired t-tests were used to compare muscle activities between KPP and FPK. Results: Passive JPS error was significantly decreased after KPP (p = 0.005) and after FPK (p = 0.003) compared to the baseline. Active JPS error was also significantly decreased after KPP (p = 0.016) and after FPK (p = 0.012) compared to the baseline. There was no significant difference in the passive and active JPS errors between KPP and FPK. SA activity during FPK was significantly increased (p = 0.024), and LT activity during FPK was significantly increased (p = 0.006). There were no significant differences in the UT and PM activity. Conclusion: FB might be recommended to immediately improve passive and active JPS and to selectively increase SA and LT muscle activities during KPP in individuals with scapular winging.

• 국제물리치료학회지
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• 제12권1호
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• pp.2279-2285
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• 2021

Background: The spinal nerves, which start at the lumbar level, are connected to the nerve innervation in the knees. Currently, there is a lack of research on the treatment of knee pain through lumbar mobilization. Objectives: To investigate the effects of lumbar joint mobilization (LJM) and transcutaneous electronic nerve stimulation (TENS) on proprioception and muscular strength in volleyball players with chronic knee pain. Design: Two group pre-posttest. Methods: A total of 26 professional volleyball players with chronic knee pain were allocated to the LJM (n=13) and TENS (n=13) groups. In the LJM group, grade III - IV amplitude was applied 3 times for 1 minute (80 times per minute) at the affected lumbar (L2-3) facet joint in the prone position. In the TENS group, the TENS treatment device was used to directly apply or 15 minutes to the area of chronic knee pain (100 Hz, 150 ㎲). Proprioception was measured by knee flexion and extension angles, and muscle strength was evaluated using an isokinetic test. Measurements were taken before and after interventions. Results: In the eye opened conditiond, proprioception significantly increased during both knee extension and flexion after LJM, while only knee extension was significantly increased in the TENS group. There was also a significant difference in knee extension between the two groups. In the eye close conditiond, proprioception was significantly improved only during knee extension in the LJM group, and the difference in knee extension between the groups was also significant (P<.05). The maximum torque of the affected knee joint was significantly improved at 60°/sec in both groups (P<.05); however, there was no difference between the two groups. There was no significant difference in the maximum flexion torque within or between the groups. Conclusion: This study suggests that LJM improved proprioception and muscular strength in volleyball players with chronic knee pain.

• 한국융합학회논문지
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• 제13권5호
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• pp.307-312
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• 2022

본 연구에서는 종아리 근육에 기능성 의류를 착용한 것이 종아리의 근기능에 어떤 영향을 미치는지 규명하고 기능성 의류가 종아리 근기능 증가에 활용가치가 있는지 검증하고자 하는데 그 목적이 있다. 연구의 대상은 하지에 이상이 없는 B 대학교의 남학생 21명을 대상으로 측정 하였다. 측정방법은 등속성근기능측정기인 CSMI사의 Humac Norm을 이용하여 오른쪽, 왼쪽 종아리에 기능성 의류 착용 전, 후 각속도 30°/sec, 120°/sec로 측정하였다. 피실험자들이 기능성 의류를 착용했을 때와 착용하지 않았을 때를 측정 해본 결과 발목 배측굴곡(Dorsi flexion)에서는 기능성 의류를 착용했을 때와 착용하지 않았을 때 유의한 차이가 나타나지 않았으나, 발목 저측굴곡(Plantar flexion)에서는 기능성 의류를 착용하였을 때 근력, 근파워, 근지구력이 유의하게 증가하는 것으로 나타났다. 따라서 종아리의 기능성 의류 착용이 운동기능 향상에 긍정적 효과가 있으며, 향후 연구에서는 대회를 앞두고 훈련을 하는 선수에게 기능성 의류를 착용한 인원과 착용하지 않은 인원의 근기능 향상정도를 비교해보는 연구를 제시하는 바이다.