• Bulletin of the Korean Chemical Society
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• v.24 no.9
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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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• v.9 no.2
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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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• v.3 no.1
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• pp.75-90
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• 1991

This study is to characterize the effects of swimming exercise on the composition of muscle fibers in rats lower limb tissue. By comparing the exercised group (4, 8 weeks) with the control group, we analyzed the difference histologically, histochemically and morphometrically. The obtained results are as follows ; 1. In the histological view, the distance between the individual muscle fibers and the muscle bundles in exercised group was shorter than that of control group. The irregular shape of sarcolemma in exercised group was observed. 2, In the histochemical view(NADH-TR. and Myosin ATPase reaction analysis), the increased populations of red and intermediate fibers were observed, whereas the white fiber was decreased. 3. In the morphometrical view, the red and intermediate fibers of tibialis anterior and gastrocnemius in exercised group were quantitatively increased, compared with control group. However, the white fiber and connective tissue in exercised group were decreased.

• Particle and aerosol research
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• v.15 no.3
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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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• v.22 no.4
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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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• v.42 no.6
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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.

• Journal of Digital Convergence
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• v.17 no.3
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• pp.463-471
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• 2019

The purpose of this study was to investigate the effect of muscle imbalance on motion of back squat. The isokinetic muscle strength of the 8 subjects was recorded for the knee flexion/extension by the cybex 770 dynamometer. Each subject performed 3 back squats with the long barbell with an intensity of 25% body weight(BW), 50%BW, 100%BW, 125%BW. During the back squat through the recorded kinematic data the subjects' maximum flexion and extension knee angle, center of mass displacement and V-COP were calculated for evaluation of the stability of the movement. For the statistical analysis independent t-test was used. Knee flexion angle and COM displacement are dominated by the reciprocal muscle ratio. V-COP factor was dominated by bilateral extension deficit. Based on the results we can know that as the intensity of the squat increased to a level control was difficult because the muscles' imbalance influenced the movement.

• Physical Therapy Korea
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• v.28 no.4
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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.

• Journal of International Academy of Physical Therapy Research
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• v.12 no.1
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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.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.307-312
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• 2022

The purpose of this study was to investigate the effects of wearing functional clothing over calf muscles on the muscle function of the calf and to verify whether functional clothing can increase calf muscle function. The participants of the study were 21 male students from University B who had no lower extremity abnormality. The measurement method was measured at 30°/sec and 120°/sec angle speed before and after wearing functional clothing on the right and left calves using Humac Norm of CSMI, a constant speed muscle function measuring instrument. No significant difference was observed during dorsiflexion when wearing functional clothing, but in plantar flexion, muscle strength and muscle endurance were significantly increased. Therefore, wearing functional clothing over the calves showed a positive effect on improving exercise function, and future research suggests a study comparing the degree of muscle function improvement between those wearing functional clothing and those not wearing it for athletes training ahead of the competition.