• 대한물리치료과학회지
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• 제24권3호
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• pp.1-11
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• 2017

Purpose: The purpose of this study was to investigate the effects of virtual reality based treadmill training on muscle architecture of gastrocnemius in chronic stroke patients. Methods: Thirty chronic stroke patients were randomly assigned to either the virtual reality based treadmill training (VRTT) group (n=15) or treadmill training (TT) group (n=15). Both groups participated in a standard rehabilitation program; in addition, the VRTT group participated in virtual reality based treadmill training for 30 minutes per day, three times per week, for 6 weeks, and TT group participated in treadmill walking training for 30 minutes per day, three times per week, for 6 weeks. Ultrasound image was used for measurement of pennation angle and muscle thickness of the medial gastrocnemius muscle at rest and during maximum voluntary contraction. Results: In the paretic side medial gastrocnemius muscle, greater improvement on the pennation angle and muscle thickness while resting and maximal voluntary contraction were observed in the VRTT group compared with the TT group. Conclusion: Findings of this study demonstrated that the virtual reality based treadmill training has an effect on muscle architecture of medial gastrocnemius in chronic stroke patients.

• 한국전문물리치료학회지
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• 제14권2호
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• pp.29-36
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• 2007

Muscle tone (stiffness/hardness) or muscle compliance changes during muscle contraction. The purposes of this study were to assess the intrarater and interrater reliabilities of the Myotonometer$^{(R)}$, electronic device that quantifies muscle tone. Two raters used the Myotonometer to assess the right bicep brachia and quadriceps muscles of 30 voluntary persons without any orthopedic or neurological problems (age range, 18~21 yrs). Muscles were measured in a relaxed state and during brief sustained voluntary maximal isometric contraction. Intrarater correlation coefficients were calculated for each muscle and for each condition (relaxed and contracted). Intrarater reliabilities (intraclass correlation coefficients, ICCs) ranged from .778 to .954, relaxed, biceps brachia), .926 to .963 (contracted, biceps brachia), .935 to .990 (relaxed, quadriceps) and .679 to .952(contracted, quadriceps). Interrater reliabilities ranged from .652 to .790 (relaxed, biceps brachii), .813 to .907 (contracted, biceps brachii), .831 to .950 (relaxed, quadriceps) and .849 to .937 (contracted, quadriceps). Myotonometer measurements had high to very high intrarater and interrater reliability for measurements of the biceps brachia and quadriceps muscles.

• 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.

• 한국전자통신학회논문지
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• 제8권8호
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• pp.1271-1276
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• 2013

본 연구는 넙다리곧은근에 적용한 정적 및 탄성적 스트레칭의 유지기간을 알아보기 위하여 남성 22명을 대상으로 정적 스트레칭 군 11명과 탄성적 스트레칭 군 11명을 스트레칭 적용 전, 적용 후 30초, 1분 후, 3분 후, 5분 후, 10분 후에 중앙주파수 및 최대 수의적 등척성 수축력의 변화를 분석하였다. 중앙주파수는 시간에 따른 변화와 군 간에서 유의한 차이를 보였다. 정적 스트레칭군과 탄성적 스트레칭군 모두에서 3분후까지 감소되었다가 증가되었다. 최대 수의적 등척성 수축력은 시간에 따른 변화와 군 간에서도 유의한 차이를 보였다. 정적 스트레칭군은 3분후까지 감소되었다가 그 이후부터 증가되었으며, 탄성적 스트레칭군은 5분후까지 감소되었다가 증가되었다. 결론적으로 스트레칭 적용 후 시간에 따라 변화를 보였으며, 정적 스트레칭보다 탄성적 스트레칭의 효과가 조금 더 길게 유지되는 것을 알 수 있었다.

• The Journal of Korean Physical Therapy
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• 제20권2호
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• pp.1-10
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• 2008

Purpose: This study examines the effects of elastic band of resistance exercise for balance control of the elderly. Methods: Thirty of eighty participants in experiment subjects who demonstrated balance-impairment through the use of primary screening tests including the one leg standing test (OLST), functional reach test (FRT) and timed up and go (TUG) were selected as subjects. Fifteen subjects that underwent muscle-strengthening exercise using an elastic band were selected as the exercise group and fifteen subjects were selected as a control group. Subjects undertook a home-based exercise program three times per week for 9 weeks. Muscle strength, functional assessment and a balance test were quantitatively measured before and after the exercise regimen. Results: After muscle strengthening exercises, changes in maximal voluntary isometric contraction (MVIC) showed a significant increase in all of the lower extremity muscles of the exercise group subjects. There were statistically significant differences between the exercise and control groups for changes in the OLST, FRT and TUG, which are functional assessments of balance ability, and changes of the unit path length and circumference area, measurement items of quantitative analysis. In addition, from examining correlations between MVIC, balance ability, it was found that an increase of muscle strength in the hip joint group of muscles among the lower extremity muscles had greater improvement in correlation with balance ability in this elderly population. Conclusion: Resistance exercise using elastic bands had significant effects on muscle strengthening in elderly subjects, with a resultant increase of lower extremity muscle strength with significant improvement of balance ability.

• Journal of Oral Medicine and Pain
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• 제9권1호
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• pp.139-145
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• 1984

A Kinematical study of bite force during voluntary isometric contraction was investigated in 20 Korean women with TMJ dysfunction and 50 Korean women a normal subject, ranging from 19 to 29 years old. The author observed maximal bite force, slope of bite force graph, curve index and duration of maximal bite force by way of the foil strain guage(MPM-3000) and Dymograph(Beckman). The obtained results were as follows : 1. Maximal bite forces were 26.48kg and 21.38kg for left and right side of normal subject and 12.85kg and 20.70kg for affected and mon-affected side of TMJ dysfunction patients. 2. The slope of bite force graph were 64.69。and 63.83。 for left and right side of normal subject and 53.14。and 69.57。for affected and non-affected side. 3. The curve indexes were 0.54 and 0.80 for left and right side of normal subject and 2.30 and 0.60 for affected and non-affected side. 4. The duration of maximal bite force were 383.12 msec and 393.60 msec for left and right side of normal subject and 345.30 msec and 312.25 msec for affected and non-affected side.

• 전기학회논문지
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• 제65권4호
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• pp.678-683
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• 2016

The study aim was to investigate a comparison of muscle activity fatigue between maximal and submaximal strength gains during the bench press in men. It was hypothesized that maximal voluntary contraction (%MVC) would similar gains between maximal and submaximal strength gains during the bench press, but median frequency (MDF) would increase in maximal compared with submaximal exercise. Employing a randomized, counterbalanced crossover design, 12 men were asked to perform maximal repetitions and submaximal repetitions (concentric: 1-s, eccentric: 1-s, 2-s/repetition) to failure with a load of 85% of 1RM for the bench press, with a 3-minute recovery between the sets. Each subject was tested for the number of repetitions and sets, total work in bench press. Surface electromyography (EMG) was recorded from the pectoralis major, deltoid anterior, and triceps brachii for %MVC and MDF. Total work was significantly higher in the submaximal repetition exercise than that the maximal repetition exercise (p<.05). Muscle fatigue of pectoralis major, deltoid anterior and triceps brachii were significantly smaller in the submaximnal repetition exercise than that the maximal repetition exercise (p<.05, respectively). However, muscle activity of pectoralis major, deltoid anterior, and triceps brachii were not significantly different between exercises. Our study showed that a smaller muscle fatigue in submaximal repetitions, despite higher in total work and a similar in muscle activity were observed. These results suggest that submaximal repetitions during the bench press would be enhanced intensity and/or volume compared with maximal repetitions exercise.

• The Journal of Korean Physical Therapy
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• 제19권3호
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• pp.11-17
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• 2007

Purpose: The purpose of this study were to analyze fatigue patterns of the rectus femoris muscle by isometric contraction. Methods: Twenty healthy subjects(10 male, 10 female) participated in this study. Maximal voluntary isometric contraction(MVIC) was measured by the dynamometer. Muscle activity was recorded from the rectus femoris muscle. During the experiment, the subject was seated in the chair. The measured items, median frequency(MDF) and root mean square (RMS), were collected from the surface EMG. All data were analyzed using repeated measures ANOVA. Results: There was significant difference of MVIC between male and female. Endurance time was significant difference by the level of MVIC but no significant in the main effect(sex) and interaction effect. The MDF and fatigue index were significant differences in the interaction effect. The RMS was not significant difference in both of main and interaction effect. The muscle fatigue patterns of female was greater than male after 60% MVIC. Conclusion: This study showed that sex differences of muscle fatigue were started from 60% MVIC.

• 한국전문물리치료학회지
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• 제9권2호
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• pp.43-50
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• 2002

This study was designed to identify the effects of walking conditions (normal walking vs. toe-walking) on electromyographic (EMG) activity of gastrocnemius, tibialis anterior, and soleus muscle. Seven healthy adult males participated in this study. The exclusion criteria were orthopedic or neurologic disease, congenital anomaly or acquired deformity, or pain in low back or lower extremities. The maximal voluntary isometric contraction for each muscle was used for the reference contraction, and EMG activity of each muscle during normal walking and toe-walking was expressed as a percentage of reference contraction. The gait cycle was determined with two foot switches, and gait was normalized as 100% gait cycle for each condition. The maximal values of EMG activity in terminal stance (30~50% of gait cycle) of each condition were compared for data analysis. No significant differences were found in EMG activity of the tibialis anterior and soleus (p>.05), whereas significant decrement was found in EMG activity of gastrocnemius during toe-walking compared to normal walking (p<.05). There is a limitation to generalize the results of this study, because small number of subjects participated for this study and only EMG was used for data collection. The treatment methods should be developed to improve gait efficiency by substituting the weakened muscles secondary to upper motor neuron, or by strengthening the distal muscles in lower extremity.

• 한국전문물리치료학회지
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• 제23권2호
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• pp.75-83
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• 2016

Background: Several studies have discussed diverse exercise methods considered to be useful for the selective contraction of the vastus medialis oblique (VMO) muscle for the treatment of patellofemoral pain syndrome. Some studies have reported that exercise methods, including hip adduction, in closed kinetic chain exercises are more effective in terms of the muscle activation of the VMO and the timing of the muscle's initial contraction. We focused on isometric contraction during a closed kinetic chain exercise with hip adduction. Objects: The purpose of this study was to examine muscle activation in the VMO and the vastus lateralis (VL) and the onset time difference between their initial contractions via closed kinetic chain isometric quadriceps femoris exercises including hip adduction. Methods: In total, 36 healthy subjects adopted two hip positions during isometric contraction of the quadriceps femoris in a closed kinetic chain exercise (hip neutral and hip adduction position). Statistical analyses were conducted using a paired t-test (${\alpha}=.05$). Results: Isometric contraction of the quadriceps femoris in a closed kinetic chain exercise caused a greater increase in VMO muscle activity in the hip adduction position [$52.68{\pm}22.21$ percentage of maximal voluntary isometric contraction (%MVIC)]than the hip neutral position ($43.43{\pm}19.85%MVIC$). The onset time difference (VL-VMO) decreased more in the hip adduction position ($-82.14{\pm}34.2ms$) than the hip neutral position ($73.94{\pm}2.94ms$). Conclusion: We recommend this exercise as a clinically useful therapeutic method for patients with patellofemoral pain syndrome due to weakening of the VMO muscle and lateral inclination of the patella.