• 대한정형도수물리치료학회지
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• 제26권2호
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• pp.29-36
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• 2020

Background: The purpose of this study was to determine the effects of whole body vibration (WBV) exercise on lower extremity muscle activity and gait ability in stroke patients. Methods: For this study, 30 stroke patients participated in this study and they were divided into WBV exercise group and sham-WBV exercise group, each group in which consisted of 15 patients. WBV group and sham-WBV group was performed by the patients for five times a week, for six weeks. sEMG was used to measure lower extremity muscle activity. Changes in the activities of the muscles, such as the vatus lateralis (VL), vastus medialis (VM), bicep femoris (BF), gastrocnemius (GCM) muscle, were analysis. Motion analysis system was used to measure gait ability. Gait ability measured the stride length (SL) and walking velocity (WV). Results: According to the results of the comparisons between the groups, after intervention, lower extremity muscle activity of VL (p<.01), VM (p<.01), GCM (p<.01). SL, WV was significant between the group (p<.01). Conclusion: This study showed the WBV exercise is effective for improving increase of muscle activity and gait ability in stroke patients.

• Physical Therapy Rehabilitation Science
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• 제10권2호
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• pp.98-105
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• 2021

Objective: The purpose of this study was to examined the kinematic relationship and differences through the range of motion (ROM), muscle activity, and vertical ground reaction force (VGRF) during forward and backward lunge movements, which are effective in improving muscle strength and balance ability of the lower extremities, and to provide clinical information on more efficient lunge movements. Design: Cross-sectional study Methods: Fifteen adult males who met the selection criteria were tested for their dominant feet.Forward and backward lunges were then performed, and the ROM, muscle activity, and VGRF were measured for kinematic analysis during the lunge movement.The differences betweenthe forward lunge and backward lunge intervention were examined using a paired t-test. Results: A significant increase in the ROM of the knee and ankle was observed during the forward and backward lunges (p<0.05). In addition, in terms of the muscle activity, the peak values of the vastus medialis oblique (VMO) and VGRF also showed a significant increase in the forward lunge compared to the backward lunge (p<0.05). Conclusions: This study showed an increase in VGRF peak value, knee and ankle ROM, and VMO muscle activity during forward lunge. Based on these results, it is considered necessary to apply differently depending on the direction of progress in consideration of the musculoskeletal situation and physical ability during the lunge movement.

• 대한물리치료과학회지
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• 제18권2호
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• pp.51-62
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• 2011

Purpose: The purpose of this study was to investigate the effect of microcurrent on fatigue of muscles in people who were flat-footed during gait. Methods: 10 flat-footed university students volunteered to participate in this study. 10 flat-footed subjects were divided into 2 groups, one group was experimental group of 5subjects(This group put on microcurrent induction shoes but the subjects were not able to feel the current.) and the other group was the control group of 5subjects(This group put on the general shoes which were similar in shape but microcurrent was not induced.) to perform double blind test and random sampling. Their gait muscle fatigue of 6 regions (vastus medialis, gastrocnemius, tibialis anterior, biceps femoris, erector spinae, and rectus abdominis muscle.) was measured by EMG MP150, Delsys Inc Boston, USA during walking and then they carried out the Harvard step with a platform (It was a arbitrarily made wooden platform of 100cm long, 50cm wide, 60cm high. They carried out climbing it for one second and descending it for one second by using the Metronome program, total 5minutes) for 5minutes. Right after that, the subjects walked on a treadmill at a speed of 4km/h for 10minutes and then their gait muscle fatigue of 6regions was assessed while they were walking on the ground as equally as before exercise. Results: The experimental group has resulted in lower average differences in gait muscle fatigue before and after exercise than those of the control group average 12.24Hz(P=0.009) at vastus medialis, average 8.52Hz(P=0.016) at gastrocnemius, average 9.16Hz(P=0.009) at tibialis anterior, average 8.66Hz(P=0.047) at biceps femoris, average 7.53Hz(P=0.016) at erector spinae, and average 7.80Hz(P=0.047) at rectus abdominis. All of the assessments of muscles have shown significant difference statistically. Conclusions: This result has shown that the use of micro current could decrease gait muscle fatigue of flat-footed people. It is recommended to use a microcurrent to reduce their gait muscle fatigue.

• 한국응용과학기술학회지
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• 제37권4호
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• pp.755-761
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• 2020

본 연구의 목적은 정적 스쿼트 동작 시 발란스 보드와 전신 진동자극기 적용이 신체 근육의 근활성도 변화에 어떠한 영향을 미치는지 검증하는 것이었다. 본 연구의 대상자는 20대 남성 20명을 대상으로 실시하였고(연령, 21.90±0.36 세; 신장, 174.30±1.09 cm; 체중, 66.50±1.00 kg; 신체질량지수, 21.90±0.31 kg/㎡), 3가지의 기본 정적 스쿼트 동작, 발란스 보드를 적용한 정적 스쿼트 동작 및 전신 진동자극기를 적용한 정적 스쿼트 동작을 수행하였으며, 표면전극을 부착한 부위는 신체 근육의 우측 복직근, 내복사근, 외복사근, 대퇴직근, 외측광근 및 내측광근으로 설정하였다. 실험을 통해 획득된 본 연구의 결과는 다음과 같다. 복직근, 내복사근 및 외복사근의 근활성도는 발란스 보드와 전신 진동자극기를 적용한 정적 스쿼트 동작 시 통계적으로 높게 나타났고(p=.001, p=.004, p=.000), 대퇴직근, 외측광근 및 내측광근의 근활성도는 전신 진동자극기를 적용한 정적 스쿼트 동작에서 통계적으로 가장 높게 나타났다(p=.000). 본 연구의 결과는 향후 정적 스쿼트 훈련 적용 시 효과적인 신체 근육을 강화시키기 위한 프로그램의 기초 자료가 될 것으로 기대된다.

• 원예과학기술지
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• 제32권5호
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• pp.710-720
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• 2014

Movements of the upper and lower limb muscles during five common gardening tasks were analyzed by using electromyography (EMG). Twenty adults aged in their twenties (mean age, $24.8{\pm}2.4$ years) were recruited. On two separate occasions, subjects visited a garden plot to perform digging, raking, troweling, weeding, and hoeing; all tasks were performed three times with 20 s intervals for each trial. To measure muscle activation during the five gardening tasks, surface EMG was used. Bipolar surface EMG electrodes were attached to eight upper limb muscles (bilateral anterior deltoid, biceps brachialis, brachioradialis, and flexor carpi ulnaris) or eight lower limb muscles (bilateral vastus lateralis, vastus medialis, biceps femoris, and gastrocnemius) on both sides of the body, for a total of 16 muscles. During the five tasks, photographs were taken of movement phases using a digital video camera. The right flexor carpi ulnaris and brachioradialis showed higher activation than the other upper and lower limb muscles measured during the tasks. All 16 upper and lower limb muscles were actively used only during digging. According to movement analysis of each activity, digging was classified into four movement phases, whereas raking, troweling, weeding, and hoeing each were divided into three movement phases. In each activity, there were high-impact phases in terms of muscle activation; the flexor carpi ulnaris and brachioradialis were identified as major muscles in each impact phase. This analysis may be used to generate biomechanical profiles of gardening tasks for practitioners when designing efficient gardening interventions for physical health or rehabilitation.

• 대한인간공학회지
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• 제25권4호
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• pp.93-101
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• 2006

This study examined whether there is a transfer effect to other joint angles and the angular specificity of muscle fatigue after 6 weeks of isometric training of the vastus medialis. Twenty subjects were randomly assigned to 30° and 90° knee flexion groups and were trained at 80% maximal voluntary isometric contraction(MVIC) three times a week for 6 weeks. The pre-and post-training values of the 80% holding time(endurance time) of MVIC, the Fatigue Index(FI), and the MVIC at 30°, 60°, and 90° were compared. After isometric training for 6 weeks, in the 30° knee flexion group, FI decreased significantly(p<0.05) only at 30°, which was the training angle; there was no change at other angles. By contrast, in the 90° knee flexion group, FI decreased significantly(p<0.05) at both the trained angle and at the other angles, indicating a transfer effect of training. MVIC did not increase significantly(p<0.05) at any trained angle in either the 30° or 90° knee flexion groups after 6 weeks of isometric training, neither did the 80% holding time of MVIC differ significantly compared with pre-training in either group. These findings suggest that training at 90° of knee flexion is more effective than training at 30° of knee flexion for obtaining a training transfer effect on muscle fatigue in the vastus medialis.

• 한국전문물리치료학회지
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• 제8권2호
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• pp.1-16
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• 2001

This study was designed to identify the effects of foot position on electromyographic (EMG) activity of the quadriceps femoris during maximum voluntary contraction (MVC) in standing. Twenty young adults who had not experienced any knee injuries were recruited. Their Q-angles were within a normal range. They were asked to stand in five different foot positions ($40^{\circ}$ externally rotated, $30^{\circ}$ internally rotated, neutral, $20^{\circ}$ plantarflexed, and $10^{\circ}$ dorsiflexed foot position). The EMG activities of the vastus lateralis (VL), rectus femoris (RF), and vastus medialis oblique (VMO) were recorded in standing by surface electrodes and normalized by MVC EMG values derived from manual muscle test. The normalized EMG activity levels (%MVC EMG) of muscles in the five foot positions were compared using repeated measures ANOVA. The EMG activity levels of the VL, RF, and VMO were the highest when foot was externally rotated. The EMG activity levels of the VL and RF were significantly different among the foot positions (p<.05). However, EMG activity levels of the VL, RF, VMO, and VMO/VL ratio did not show significant differences in each foot position (p> .05). The results suggest that the quadriceps femoris may be effectively activated by performing MVC at an externally rotated foot position. Therefore, the externally rotated foot position can be considered as an effective foot position for quadriceps femoris strengthening exercise. Further studies are needed to identify whether there are differences in the effects of foot position on muscle strength after MVC exercise of quadriceps femoris in standing.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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• pp.336-345
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• 2023

The present study was designed to evaluate changes in neuromuscular properties and the structural and qualitative characteristics of muscles during submaximal isometric contractions at low-to-relatively vigorous target forces and to determine their influence on force steadiness (FS). Thirteen young adult males performed submaximal isometric knee extensions at 10, 20, 50, and 70% of their maximal voluntary isometric contraction using their non-dominant legs. During submaximal contractions, we recorded force, EMG signals from vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF), and ultrasound images from the distal RF (dRF). Force and EMG standard deviation (SD) and coefficient of variation (CV) values were used to measure FS and EMG steadiness, respectively. Muscle thickness (MT), pennation angle (PA), echo intensity (EI), and texture features were calculated from ultrasound images to assess the structural and qualitative characteristics of the muscle. FS, neuromuscular properties, and texture features showed significant differences across different force levels. Additionally, there were significant differences in EMG_CV among the quadriceps at the 50% and 70% force levels. The results of correlation analysis revealed that FS had a significant relationship with EMG_CV in VM, VL, and RF, as well as with the texture features of dRF. This study's findings demonstrate that EMG steadiness and texture features are influenced by the magnitude of the target force and are closely related to FS, indicating their potential contribution to force output control.

• 대한의용생체공학회:의공학회지
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• 제31권3호
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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.

• 대한물리의학회지
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• 제15권1호
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• pp.113-121
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• 2020

PURPOSE: The study examined the effects of non-elastic taping on the knee and ankle joints of stroke patients to increase muscle activity, balance and gait ability. METHODS: In this study, 10 stroke patients were assigned to experimental group (knee and ankle joint non-elastic taping and PNF technique) and control group (PNF technique). The experimental group applied the PNF technique for 30 minutes after attaching the inelastic tape, and the control group performed the PNF technique for 30 minutes. five times a week for a total of four weeks (20 times). RESULTS: The muscle activity of Vastus Medialis and Tiblialis Anterior showed significant differences between the experimental and control groups. BBS and 10MWT also showed significant differences between the experimental and control groups. CONCLUSION: In this study, the muscle activity, balance and walking on the paraplegic side of stroke patients using inelastic taping, and applied inelastic taping on two joints in a different way from the previous study, Therefore, it will have the advantage of increasing paralysis side muscle activity and improving balance and walking ability.