• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.442-447
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• 2017

The purpose of this study was to establish norm-referenced criteria for the isokinetic strength of the elbow joint in Korean high school baseball players. Two hundred and one high school baseball players participated in this study, none of whom had any medical problem with their upper limbs. The elbow flexion/extension test was conducted four times at a speed of $60^{\circ}/sec$. The HUMAC NORM (CSMI, USA) system was used to obtain the values of the peak torque and peak torque per body weight. The results were presented as norm-referenced criterion valuesusing the 5-point scale of Cajori which consists of five stages (6.06%, 24.17%, 38.30%, 24.17%, and 6.06%). In the results of this study, the peak torques of the elbow (flexor and extensor?) at an angular velocity of $60^{\circ}/sec$ were $37.88{\pm}8.14Nm$ and $44.59{\pm}11.79Nm$, and the peak torque per body weight of the elbow (flexor and extensor?) were $50.06{\pm}8.66Nm$ and $58.28{\pm}12.84Nm$, respectively. The reference values of the peak torque and peak torque per body weight of the elbow flexor and extensor were setat an angular velocity of $60^{\circ}/sec$. On the basis of the results analyzed in this study, the following conclusions were drawn. There is a lack of proper studies on the elbow joint strength, even though the most common injury in baseball players occurs in the elbow joint. Therefore, we need to establish a standard muscle strength in order to prevent elbow joint injuries and improve their performance. The criteria for the peak torque and peak torque per body weight established here in will provide useful information for high school baseball players, baseball coaches, athletic trainers and sports injury rehabilitation specialists in injury recovery and return to rehabilitation, which can beutilized as objective clinical assessment data.

• Physical Therapy Korea
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• v.13 no.3
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• pp.75-83
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• 2006

The purpose of this study was to examine the isokinetic moment of quadriceps and hamstring strength ratio among women of different ages. The study population consisted of 1,184 women referred to the Health Promotion Center at the S district. All subjects were aged 20 to 69 years old and divided into 5 groups; 20s (n=248), 30s (n=255), 40s (n=248), 50s (n=228), and 60s (n=205). The strength of the knee extensor and flexor, quadriceps, and hamstring of all the participants were assessed at 60 degrees/second with an isokinetic machine. We calculated the peak torque, peak torque %BW (%Body Weight), deficit of peak torque and hamstring/quadriceps ratio of the knee. The data were analyzed by one way ANOVA to investigate statistical differences in strength variation between different age groups and were computed by ${\Delta}%$ difference from women in their 20's. The results were obtained as follows: 1. Peak torque of the knee extensor, quadriceps, were significantly reduced in women older than 30, but peak torque of the knee flexor, hamstring, were significantly reduced in women older than 50 compared to women in their 20's. (p<.05). 2. Peak torque %BW of the knee extensor, quadriceps, were significantly reduced in women older than 20, but peak torque %BW of knee flexor, hamstring, were significantly reduced in women older than 40 compared to women in their 30's (p<.05). 3. Compared to the women in their 20's, there was no significant difference among any of the age groups in the deficit of peak torque of the knee extensor and flexor, but the deficit of peak torque of knee extensor among women between 30 and 50showed significant difference within the normal range of deficit. 4. Compared to the women in their 20's, there was no significant difference among any of the age groups in the hamstring/quadriceps ratio These results showed that peak torque, peak torque %BW, deficit of peak torque, and hamstring/quadriceps ratio of the knee were reduced in each age group, but especially among the women over 50. Further longitudinal study may be needed to see if volume of muscle mass and intervention of exercise affect knee strength in spite of aging.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.142-150
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• 2015

Purpose: Restoration of ankle stability through the strengthening exercise of peroneus muscles is considered an important factor for achievement of successful outcomes, in the rehabilitation program following ankle ligament injuries. However, there were few definitive data on normal muscle strength, including eversion power by peroneus muscles. This study was conducted to evaluate the muscle strength of ankle joint measured using an isokinetic dynamometer in normal Koreans. Materials and Methods: Sixty adults (120 ankles) were recruited and divided into three groups (20 in their twenties, 20 in thirties, and 20 in forties). Each group consisted of 10 males and 10 females. The selection criteria were no history of ankle injury and no evidence of instability. The peak torque, total work, and deficit ratio were measured using the Biodex$^{TM}$ (Biodex Medical Systems). Differences in muscle strength by age, gender and dominant versus non-dominant side were analyzed. Results: The peak torque of dorsiflexion was average 31.5 Nm at $30^{\circ}/s$ of angular velocity and 18.8 Nm at $90^{\circ}/s$; average 69.3 Nm ($30^{\circ}/s$) and 42.4 Nm ($90^{\circ}/s$) on plantarflexion; average 19.6 Nm ($30^{\circ}/s$) and 10.8 Nm ($90^{\circ}/s$) on inversion; average 12.9 Nm ($30^{\circ}/s$) and 8.0 Nm ($90^{\circ}/s$) on eversion. The deficit ratio of strength in women was average 61.1% of men on dorsiflexion; average 66.2% on plantarflexion; average 48.5% on inversion; average 55.4% on eversion. The deficit ratio in non-dominant foot was average 88.6% of dominant foot on dorsiflexion; average 90.1% on plantarflexion; average 85.1% on inversion; average 85.6% on eversion. Conclusion: The muscle strength of the ankle joint showed a tendency to weaken with age. There were significant differences in muscle strength by gender and dominancy. Further studies for comparison of patients with ankle instability, a comparison between before and after surgery for instability, the correlation between clinical outcomes and the recovery in muscle strength will be needed.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.1
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• pp.27-37
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• 2008

Purpose : Today, it enjoys a sports and a leisure where the anterior cruciate ligament(ACL) injury patient increase. The knee joint is important means of human body movement and to do an important duty when it encounters ACL injuries of the knee joint and the many restriction follows in the life which is ordinary. When it is damaged ACL, it comes to determinate that ACL reconstruction and preservation treatment that the according to condition of ligament and knee joint. After ACL reconstruction, that is the fact which already becomes known the exercise treatment advances a recovery and to reduce a sequela. Methods : we researched the method of exercise treatment after anterior cruciate ligament reconstruction operation by journal of science direct and KISS in daecu university. Results : The representative exercise treatment is isometric exercise, isokinetic exercise isotonic exercise and complex exercise but what kind of exercise treatment most is effective, it revealed and support it was not. The method of exercise treatment is very various, so It causes a confusion made to the therapist and patients. So it executes once again it sought the kinetic therapeutic method which is efficient from this research and it tried to observe preceding research after ACL reconstruction. To operation a various the exercise treatments, operation only the treatment which is general compared to it was effective in muscular power and muscle functional improvement. But this like improve despite with the exercise treatment consequence which is continuous from research of most the pain leg compares to the health leg, it appeared the discrepancy which is a muscular power, a muscular endurance and a hypertrophy muscle etc, to the health leg or before operating 100% of muscular power to having gets the many therapy time was the recovery rate. Conclusion : Therefore after ACL reconstruction, it will become the many research continuously which is improve the muscle functional and ROM of the exercise treatment method and From therapeutic site of the patients it does to memorizes knowledge in advance about ACL injuries and the application the isokinetic treatment or exercise program are the set of necessary, frequency and amusement that considers complex what kind of therapeutic exercise becomes accomplished with the patient take care of attention.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.538-546
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• 2017

The purpose of this study was to investigate the effect of neuromuscular electrical stimulation (NMES) and transcutaneous electrical nerve stimulation (TENS) on muscular strength, pain, range of motion and fear-avoidance in anterior cruciate ligament reconstruction (ACLR) patients. The subjects of this study who received ACLR after arthroscopic injury were divided into two groups: NMES (n=14) and TENS (n=14). Each group received intervention after routine physical therapy. Each electrotherapy intervention was applied regularly for a total of 12 times, 3 times a day (30 minutes) for 4 weeks. The evaluation by intervention method included isokinetic muscle strength in flexion and extension of the knee joint, pain, range of motion of the knee joint, and fear-avoidance beliefs. The results showed significant improvement in pain, range of motion, and fear-avoidance beliefs in both groups (p<0.05). However, there was a significant improvement in isokinetic knee flexion and extension strength only in the NMES group (p<0.05). There was no significant difference between the two electrotherapy methods in muscle strength, pain, range of motion, and fear-avoidance beliefs. These study results suggest that NMES and TENS can be effective intervention methods for pain, range of motion, and fear-avoidance response in patients with ACLR, but to improve muscle strength NMES may be more effective.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.217-226
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• 2010

The lower limb orthosis with a pneumatic rubber actuator, which is intended for the assistance and the enhancement of muscular activities of lower limbs was developed in this study. Compared to other knee extension assistive devices being developed by other researchers, our device is designed especially for the elderly people and intended only for slight assistance so that the subjects can keep their muscular strength. For the effectiveness of system, muscular activities of major muscles in lower limbs during sit-to-stand (STS) and squat motion were measured and analyzed. Subjects were performed the STS and squat motion with and without lower limb orthosis. We made comparison muscular activities between with and without lower limb orthosis. Lower limb orthosis was controlled using muscular stiffness force feedback that is controlled by muscular activities of the measured muscle from force sensor. For analysis of muscular activities, electromyography of the subjects was measured during STS and squat motion, and these were measured using MP 150(BIOPAC Systems, Inc.). Muscles of interest were rectus femoris(RF), vastus lateralis(VL), vastus medialis(VM) and vastus intermedius(VI) muscles in lower limbs of the right side. A biodex dynamometer was used to measure the maximal concentric isokinetic strength of the knee extensors of wearing and not wearing orthosis on right side. The test were performed using the concentric isokinetic mode of test with the velocity set at 60°/s for muscles around the knee joints. The experimental result showed that muscular activities in lower limbs wearing orthosis using muscular stiffness force of a vastus medialis muscle was reduced and knee extension torque of an knee joint wearing lower limb orthosis was increased. With this, we confirmed the effectiveness of the developed lower limb orthosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.691-700
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• 2016

This study was performed to provide data for developing a more effective and practical pilates exercise program for young women. To meet this purpose, 20 young women were assigned to both groups. The experiment was conducted according to the experimental procedure. Ten subjects in the pilates exercise group performed exercise for 60 minutes everyday at a frequency of 3 days per week for 8 weeks. The subjects in both groups were measured for their physical composition, isokinetic muscular strength in legs, and body balance before and after the experiment. After 8 weeks, the pilates exercise group's body composition showed significantly increased muscular amount (p <.01). There was a statistical increase in knee joint muscle function. For the right knee joint and left knee joint, right knee joint extensor muscle's maximum muscular strength and total work significantly increased under conditions of $60^{\circ}/sec$ (p<.05). Under conditions of $180^{\circ}/sec$, there were statistically significant increases in left knee joint flexor muscle's maximum muscular strength (p<.05). For balance, balance of both legs and right leg showed statistically increases (p<.05).

• Journal of Life Science
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• v.19 no.12
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• pp.1821-1828
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• 2009

The purpose of this research was to investigate how the plyometric training and weight training program, applied in the field for exercise performance of throwing players, influenced improvement of athletic abilities, including agility, maximum muscular power, and strength. After implementing plyometric training and weight training to 21 high school throwing players for 10 weeks, we designed the next step. The 21 subjects were divided into two groups - women's group and men's group. All subjects were tested to determine agility using sidestep, burpee test, reaction time, lower body power and strength using standing long jump, standing jump, 30 m running, squats and leg presses. Additionally, isokinetic strength was measured using Cybex isokinetic dynamometer. The results showed that both groups demonstrated improvement in the standing long jump, standing jump and 30 m running after training. Particularly, the women's group indicated better improvement. Second, women's groups showed higher improvement in the sidestep and burpee test. However, in the reaction time test, the men's group indicated better improvement. Third, both groups showed better improvement in squats and leg presses after training. Particularly, the women's group indicated better improvement. Fourth, in the left and right side extension torque and flexion torque at a velocity of $60^{\circ}$/sec, both groups showed better improvement after training. In the left side extension peak torque, the men's group showed higher improvement, but the women's group showed higher improvement in the left side flexion and extension peak torque. Fifth, both groups showed better improvement in bench pressing and back strength after training. Particularly, the women's group indicated higher improvement.

• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.429-440
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• 2005

The purpose of this study was to compare the effects of knee joint position sense following local and general load protocols in 25 healthy male subjects. Proprioception of the knee joint was evaluated by measuring absolute angular errors at matching angles before, after and between 2 different types of load protocols. Proprioception tests(on the dominant knee) were performed in which proprioception of the passivepassive reproduced and active-active reproduced knee position was measured. Local load was provided with maximum isokinetic knee extension-flexion on the isokinetic dynamometer(Cybex), and general load was 10 minutes running on a treadmill. Peak torque(knee extension and flexion) and heart rate(beats per minute) was evaluated as an indicator of local and general fatigue during load protocols. The results were as follows: 1. For pasive-pasive reproduced knee position test, significant difference in absolute angular errors after general load protocol was detected compared with that before general load protocol(P<.05), significant difference in absolute angular errors after local load protocol was detected compared with that before local load protocol(P<.05). However, no significant difference in absolute angular errors of general load protocol was detected compared with that of local load protocol (P>.05), no significant difference in absolute angular errors of local load protocol was detected compared with that of general load protocol(P>.05). 2. For active-active reproduced knee position test, significant difference in absolute angular errors after general load protocol was detected compared with that before general load protocol(P<.05), significant difference in absolute angular errors after local load protocol was detected compared with that before local load protocol (P<.05). Also, significant difference in absolute angular errors of general load protocol was detected compared with that of local load protocol(P<.05), significant difference in absolute angular errors of local load protocol was detected compared with that of general load protocol(P<.05). 3. A significant decrease of peak torque of knee extensors and flexors was seen after local load, although heart rate was significantly increased(P<.05). No significant change of peak torque of knee extensors and flexors was seen after general load(P>.05), although heart rate was also significantly increased(P<.05). The previous study revealed that knee proprioception is significantly altered when the muscle mechanoreceptors are dysfunctional due to muscle fatigue, although the joint mechanoreceptors have no significantly effect on knee proprioception when the presence of knee muscle fatigue. However, the results of this study are different from those of the previous study in that muscle weakness of the knee could not be seen after general load. This study shows that general load may diminish motor control by the central nervous system. Proprioceptional decline without muscle weakness of knee after general load suggests a change in the proprioceptional pathway without influence from muscle mechanoreceptors.

• Journal of the Korean Chemical Society
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• v.25 no.6
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• pp.376-382
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• 1981

The rates and the activation parameters for the reaction of phenacyl bromide with substituted anilines in methanol and dimethylformamide were measured. The effects of substituted anilines were discussed. The rate of the reaction was increased with the electron donating power of substituent and showed larger value in DMF than in MeOH. The isokinetic relationship was shown between ${\delta}H^{\neq}$ and ${\delta}S^{\neq}$, isokinetic temperature was 539 and $400^{\circ}C$ in MeOH and DMF respectively, but p-nitro aniline was deviated from linearity in both solvents caused by solvent effects. The excellent linear relationship between log k and p$K_a$ of substituted anilines was observed by following equation. log k = 0.57p$K_a$-1.28 (r = 0.996) in MeOH at $45^{\circ}C$, log k = 0.65p$K_a$-0.88 (r = 0.970) in DMF at $45^{\circ}C$. From the Hammett plot, this reaction was a nucleophilic displacement of aniline to phenacyl bromide and the following equation was obtained at $45^{\circ}C$. log k/$k_0$ = -2.00${\sigma}$ + 0.06 (r = 0.985) in MeOH; log k/$k_0$ = -2.22${\sigma}$ + 0.08 (r = 0.995) in DMF. Large deviation of p-nitro aniline in DMF is resulted from solvent effects too. From above results, the substituent effect of this reaction can be described as $S_N2$ mechanism and bond formation more proceeds in DMF relative to MeOH.