• 대한예방한의학회지
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• 제12권3호
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• pp.115-128
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• 2008

Purpose : This study was performed to distinguish the muscle activation of vastus medialis and biceps femoris through open and closed kinetic chain exercise. Methods : 31 healthy male and female students in Daegu Health College were participated in this study. All subjects were conducted three types open and closed kinetic chain exercises to examine muscle activity during the last four seconds using the sEMG system. Collected EMG data were normalized using the maximal voluntary isometric contraction(MVIC). Results : MVIC of each muscle was showed significantly increased(p<0.5). In the case of open chain exercise, the type 3 exercise most increased than type 2 and 3 exercise in vastus medialis than biceps femoris muscle. The closed chain exercise presented type 6 exercise most increased than type 4 and 5 exercise in biceps femoris than vastus medialis. Conclusion : This study finally proved that muscle activity which maintains stability of knee differ from depending on the types of exercises. Therefore, the combination of the two chain exercises is believed to greatly contribute to increments in muscle activity.

• 대한물리의학회지
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• 제10권2호
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• pp.63-71
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• 2015

PURPOSE: The purpose of this study to investigate the effects of exercise on lumbar stabilization in muscle activity and isokinetic muscle strength of female with chronic low back pain. METHODS: The candidates was chose to twenty women in their 30s and 40s complaining back pain for over 12 weeks and consist of 10 people for lumbar stabilization and general physical therapy group(PL group), another 10 people for general physical therapy group(GP group). Lumbar stabilization exercise was conducted for 8 weeks and was comprised of 60 minutes for two times a week. In order to examine the effects of lumbar stabilization, results in the present study were analyzed maximal voluntary isometric contraction (MVIC) using electromyogram to measure muscle activity and isokinetic performance including peak torque and average power at the pre to post. RESULTS: The following are results in this study. The MVIC and isokinetic muscle strength were gradually increased in all group. As the result of the test of the MVIC and isokinetic muscle strength, the difference of lumbar stabilization and general physical therapy group is statistically more significant than that of general physical therapy group. CONCLUSION: In the present study, results indicate that lumbar stabilization helps to improve the muscle activity and isokinetic muscle strength.

• 한국전문물리치료학회지
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• 제20권2호
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• pp.1-10
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• 2013

The purpose of this study was to determine the effect of the changes that occur in the leg muscle activity of unstable surface with different levels of air pressures. Three groups of college students have been placed randomly on unstable surfaces with different air pressures at group 1.0 psi ($n_1$=36), group 1.4 psi ($n_2$=40), and group 1.8 psi ($n_3$=40). Using surface electromyography, the recruitment of the tibialis anterior, peroneus longus, and the gastrocnemius was measured. Maximal voluntary isometric contraction was measured at the different air pressures based on the manual muscle test, then normalizing the value to %maximal voluntary isometric contraction (%MVIC). The tibialis anterior muscle activity was significant change from the unstable surface with difference levels of air pressures between group 1.0 psi and 1.8 psi and between group 1.4 psi and 1.8 psi. peroneus longus muscle activity was significant changes in muscle activity occurred between 1.0 psi and 1.4 psi group and between 1.0 psi and 1.8 psi group. Gastrocnemius muscle activity was significant change in muscle activity occurred between 1.0 psi and 1.4 psi group and between 1.0 psi and 1.8 psi group. In conclusion it identify that 1.0 psi group is most effective on muscle activity than the other groups. These suggest that the rehabilitation or strengthening of patients with ankle injuries, balance exercise with low air pressure like 1.0 psi can be more effective.

• Physical Therapy Rehabilitation Science
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• 제9권4호
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• pp.287-294
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• 2020

Objective: This study aimed to investigate the effects of an ultrasound-based bar graph proportional to the quadriceps muscle thickness as a real-time visual feedback training tool in the elderly. Design: Cross-sectional study. Methods: Twenty-four elderly persons participated in this study and were randomly divided into three groups: oral training group (n=8, group 1), ultrasound imaging group (n=8, group 2), and graph group (n=8, group 3). In the pre condition, all participants performed maximal voluntary isometric contraction (MVIC) of the quadriceps with knee extension three times with oral training. In the post condition, group 1 performed MVIC of the quadriceps with oral training, group 2 performed MVIC of the quadriceps with real-time visual feedback using ultrasound imaging, and group 3 performed MVIC of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness, three times for all groups. Muscle thickness, activity (mean, peak), tone, stiffness, logarithmic decrement, relaxation, and creep were measured in both conditions in all participants. Results: Visual feedback with a bar graph showed significant effects on muscle thickness, mean muscle activity, and peak muscle activity compared with oral training and visual feedback with ultrasound imaging (p<0.05). Conclusions: Isometric training of the quadriceps with real-time visual feedback using a bar graph proportional to the quadriceps muscle thickness may be more effective than other methods in improving muscle thickness and muscle activity. This study presented a tool that can help increase muscle thickness in the elderly.

• 대한임상전기생리학회지
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• 제3권1호
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• pp.49-59
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• 2005

This study assigns each 8 of 24 normal persons to control group(Group I), strength increase group(Group II) and endurance increase group(Group III) to analyze differences in changes of strength and endurance with surface electromyography and kinetics according to application modes of neuromuscular electrical stimulation(NMES). Group I had not any treatment, group II performed 15 repeated contraction with 60% intensity of maximal voluntary isometric contraction(MVIC) by setting 10-sec on time and 50-sec off time and group III conducted 30 repeated contraction with 30% intensity of MVIC by setting 10-sec on time and 20-sec off time. For neuromuscular electrical stimulation, 2,500 Hz of Russian current, 35 pps of pulse rate and 200 of pulse width. Neuromuscular electrical stimulation was conducted by five times for total 4 weeks. Before and after experimentmotor unit action potential of vastus medialis, rectus femoris and vastus lateralis were measured with sEMG, median frequency(MDF) was analyzed, and thus the following results were obtained. There was significant difference in the period of measuring vastus medialis and rectus femoris in change of MDF and interaction among groups with analysis of surface electromyography before and after neuromuscular electrical stimulation(p<.001) and in particular, there was a remarkable change among groups according to the period of measurement. In conclusion, NMES influenced changes of strength and endurance according to its application modes and in particular, it was found that strength increment application had a significant influence on strength increment in applying short-time NMES.

• 대한임상전기생리학회지
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• 제5권1호
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• pp.59-71
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• 2007

The purpose of this study was to study for the change of neural adaptation by muscle contraction force when neuromuscular electrical stimulation(NMES) was applied. Sixteen subjects(8 male, 8 female) without neuromuscular disease volunteered to participate in the study. All subjects were divided into two subgroups: control(no electrical stimulation) group, NMES(50% maximal voluntary isometric contraction) group. NMES training program was performed in the calf muscle over three times a week for 12 weeks. Before and after experiment MVIC of ankle plantar flexor was measured by use of dynamometer. H-reflex and V-wave in tibial nerve were measured. The following results were obtained; MVIC and V/Mmax ratio were significantly increased in the electrical stimulation groups. However, H/Mmax ratio was not changed. It was closely relationship between MVIC and V/Mmax ratio. In this study, the effect of neural adaptation of central neural adaptation was found in this study. Accordingly, NMES means not only a change of muscle fiber and skeletal muscle volume but also a effect of neural adaptation of central neural drive. Also, it was found that there was closely relationship between MVIC and neural adaptation of central neural drive by NMES.

• 한국전문물리치료학회지
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• 제31권1호
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• pp.18-28
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• 2024

Background: Lateral instability of the ankle is one of the most common causes of musculoskeletal ankle injuries. The peroneus longus (PL) and peroneus brevis (PB) contribute to ankle stability. In early rehabilitation, isometric exercises have been selected for improvement of ankle stability. To effectively train the peroneal muscles during eversion, it is important to consider ankle and body posture. Objects: This study aimed to compare activation of the PL, PB, and biceps femoris (BF) muscles during eversion in different ankle postures (neutral [N], plantarflexed [PF]) and body postures (sitting and side-lying). Methods: Thirty healthy individuals with no history of lateral ankle sprains within the last 6 months were included in the study. Maximal isometric strength of eversion and muscle activation were measured simultaneously. Muscle activation at submaximal eversion was divided by the highest value obtained from maximal isometric eversion among the four postures (percent maximal voluntary isometric contraction [%MVIC]). To examine the differences in muscle activation depending on posture, a 2 × 2 repeated measures analysis of variance (ANOVA) was conducted. Results: There were significant interaction effects of ankle and body postures on PL muscle activation and evertor strength (p < 0.05). The PL muscle activation showed a significantly greater difference in the side-lying and PF conditions than in the sitting and N conditions (p < 0.05). Evertor strength was greater in the N compared to the PF condition regardless of body posture (p < 0.05). In the case of PB and BF muscle activation, only the main effects of ankle and body posture were observed (p < 0.05). Conclusion: Among the four postures, the side-lying-PF posture produced the highest muscle activation. The side-lying-PF posture may be preferred for effective peroneal muscle exercises, even when considering the BF muscle.

• 대한물리치료과학회지
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• 제21권1호
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• pp.13-20
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• 2014

Purpose : The purpose of this study was to analyze and compare the surface electromyography(EMG) activity of trunk region muscle between normal subjects and chronic low back pain(CLBP) patients during one leg stance. Methods : The subjects were 27 people, were consisted of 12 subjects who don't have low back pain and 15 subjects who have low back pain from 19 to 28 year of age(mean age 22.22). We used surface EMG to evaluate the activity of the Rectus abdominis, External abdominal oblique, Quadratus lumborum, Gluteus medius muscle. We used independent two samples t-test for statistical data. Results : The result of this study showed that the maximal voluntary isometric contraction(%MVIC) ratio of the trunk muscles was higher in patients with CLBP than in normal subject. But there were no statistically significant differences. There were statistically significant differences of the activity of the Quadratus lumborum, Gluteus medius muscle(p<0.05).

• 한국전문물리치료학회지
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• 제16권2호
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• pp.59-66
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• 2009

This study investigated the irradiation pattern of muscles on the affected side in stroke patients after application of diagonal 2 extension (D2 ex) proprioceptive neuromuscular facilitation in the unaffected upper extremity. Seven stroke patients participated. Electromyographic activities were recorded in the iliopsoas, biceps brachii, and triceps brachii were recorded by surface electrodes at rest, D2 ex with knee extension, and D2 ex with knee 90 flexion, normalized by maximal voluntary isometric contraction (MVIC) values. The medial frequencies of biceps brachii in both sides were also measured to compare muscle type recruited. %MVIC of biceps brachii and triceps brachii were significantly higher in D2 ex than at rest (p<.05). There was no difference in median frequency of biceps brachii between the affected and unaffected side (p>.05). This suggests that proprioceptive neuromuscular facilitation using D2 ex may improve muscle activities of the paretic side and that the irritation pattern of the affected side may respond to maintain body equilibrium according to movement of the sound side.

• The Journal of Korean Physical Therapy
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• 제21권1호
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• pp.1-7
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• 2009

Purpose: The aim of this study was to determine the effect of proprioceptive neuromuscular facilitation (PNF) leg patterns on muscle activation of paretic and nonparetic arm in post-stroke hemiparetic subjects. Methods: Eighteen hemiparetic patients participated in this study. Each subject was asked to perform four PNF leg patterns against maximal manual resistance on nonparetic leg. EMG data were collected from biceps and triceps on the paretic and nonparetic side. The measured EMG data was digitized and processed to root mean square (RMS) and expressed as percentage maximal voluntary isometric contraction (％MVIC). The data were analyzed using paired t-test and one-way analysis of variance (ANOVA) with repeated measures to determine the statistical significance. Results: The results of this study were summarized as follows: Firstly, during four PNF patterns application, all of the ％MVIC values of biceps and triceps in paretic and nonparetic arms increased significantly compared with resting condition (p<0.05). Secondly, there was a significant difference in ％MVIC of paretic biceps between PNF leg pattern 1 and 4 (p<0.05). Conclusion: In conclusion, regardless of the kinematic components of PNF leg patterns, all of the muscle activation of biceps and triceps in paretic and nonparetic arm was significantly increased. The finding of this study indicates that irradiation effect caused by PNF leg patterns is beneficial for increased muscle activation of both paretic and nonparetic arms in post-stroke patients.