• 대한통합의학회지
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• 제2권1호
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• pp.15-21
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• 2014

Purpose : The aim of this study was to find out differences between muscle activity of quadriceps according to hip angle. Method : 40 healthy adults produced maximum isometric muscle contraction of quadriceps femoris and each part of the quadriceps femoris were measured with a surface EMG in hip joint angle of $90^{\circ}$, $135^{\circ}$, $180^{\circ}$. Result : There was no significant difference between muscle activity of vastus medialis and lateralis according to hip angle. But there was significant difference in muscle activity of rectus femoris and the muscle activity was maximum at 135 degrees of hip angle. Conclusion : In conclusion, maximum muscle activation of rectus femoris is affected by hip angle, and the findings from this study may be helpful for physical therapists in selecting hip position when instructing patients to do Q-setting exercise. So, we suggest that patients perform Q-setting exercise at 135 degrees of hip angle for the best result.

• 대한정형도수물리치료학회지
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• 제15권2호
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• pp.50-62
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• 2009

Purpose: to analyze and compare mucsle activity of Quadriceps femoris depending on the existence of taping while normal people walk forward and backward on treadmill when the slope and speed changes on treadmill. Method: Among 40 people who participated in this study, 20 experimenter who apply a taping walk forward and backward to 0%, 5%, 10% gradient per 2km/h and 4km/h using treadmill to give arbitrary walking behavior, 20 experimenter who doesn't apply a taping also walk forward and backward to 0%, 5%, 10% gradient per 2km/h and 4km/h using treadmill. To analyze muscle activity, We use an electromyography and Kinesio tape of good elasticity for obtained suffient effects in the experiment. Result: During backward walking in 2km/h, Vastus medialis and Vastus lateralis showed significant differences(p<0.05) when apply a taping. During backward walking in 2km/h, Vastus medialis and Rectus femoris, and Vastus lateralis all showed significant differences(p<0.05). During backward walking in 2km/h, Vastus medialis and Vastus lateralis showed significant differences in 10% gradient(p<0.05). During backward walking in 4km/h, Vastus medialis and Rectus femoris, and Vastus lateralis all showed significant differences(p<0.05). During backward walking in 4km/h, By the difference in slope, Vastus medialis and Vastus lateralis showed significant differences between 0% and 10% gradient(p<0.05). Conclusion: In comparison to muscle activity of Quadriceps femoris when apply a taping according to slope and speed during forward and backward walking on treadmill, when apply a taping and walk backward and 10% gradient on treadmill in 4km/h, maximum of muscle activity is shown.

• 대한인간공학회지
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• 제14권2호
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• pp.1-14
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• 1995

Neuromuscular difference between normal subjects and low-back pain patients has been identified in terms of neural excitation signal measured by Electromyography (EMG) under the dynamic flexion/extension trunk motion. Ten healthy subjects and ten low-back pain patients were recruited for this study. New parameters and normalization technique were introduced to quantify the muscle excitation pattern among the flexor-extensor pairs of muscles : rectus abdominis (RA)-erector spinae (ES at L1 and L5 level), external oblique (EO)-internal oblique (IO), rectus femoris (quadricep : QUD)-biceps femoris( hamstring : HAM), and tibialis anterior (TA)-gastrocnemius (GAS). Results indicated that the temporal EMG pattern such as peak timing difference between the hip flexor (QUD) and extensor (HAM) and the duration of coexcitation between ES at L5 and RA muscle pairs showed a statistically significant difference between normal subjects and low-back pain patients. Improtantly, this study presented a new technique to identify the dynamic muscle excitation pattern that canb be least affected by EMG-length-velocity relationship. Further study can performed to validate this method for clinical application to quantitatively identify the low-back pain patients in the future.

• PNF and Movement
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• 제17권2호
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• pp.207-214
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• 2019

Purpose: Although multi-directional reaching exercises are commonly used clinically, the effects of specific movement directions on the muscle systems of the lower extremities have not been explored. We therefore investigated lower extremity muscle activity during reaching exercises with different sagittal and horizontal plane movements. Methods: The surface electromyography responses of the bilateral rectus femoris, tibialis anterior, peroneus longus, and gastrocnemius muscles were measured during reaching exercises in three directions in the horizontal plane (neutral, $45^{\circ}$ horizontal shoulder adduction, and $45^{\circ}$ abduction) and three directions in the sagittal plane (neutral, $120^{\circ}$ flexion, and $60^{\circ}$ flexion). A total of 20 healthy, physically active participants completed six sets of reaching exercises. Two-way repeated ANOVA was performed: body side (ipsilateral and contralateral) was set as the intra-subject factor and direction of reach as the inter-subject factor. Results: Reaching at $45^{\circ}$ horizontal shoulder adduction significantly increased the activity of the contralateral rectus femoris and gastrocnemius muscles, while $45^{\circ}$ horizontal shoulder abduction activated the ipsilateral rectus femoris and gastrocnemius muscles. The rectus femoris activity was significantly higher with reaching at a $120^{\circ}$ shoulder flexion compared to the other conditions. The gastrocnemius activity decreased significantly as the shoulder elevation angle increased from $60^{\circ}$ to $120^{\circ}$. Conclusion: Our results suggest that multi-directional reaching stimulates the lower extremity muscles depending on the movement direction. The muscles acting on two different joints responded to the changes in reaching direction, whereas the muscles acting on one joint were not activated with changes in reaching direction.

• 한국전문물리치료학회지
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• 제13권3호
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• pp.1-9
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• 2006

The purpose of this study was to assess the influence of spine orthosis and sit-to-stand motor strategies on ground reaction force (GRF) and lower extremity muscle activity. Twenty healthy adult men participated, and subjects randomly performed sit-to-stand motions in three different conditions: Momentum-transfer strategy (MTS); MTS with spine orthosis; and zero-momentum strategy (ZMS) with spine orthosis. GRF data, onset time, and muscle activity were determined and compared using force plate and electromyography. Data were statistically analyzed by the SPSS version 13.0. One-way repeated analysis of variance (ANOVA) was used to determine the statistical significance, and least significant difference was used as a post hoc test. The level of significance was .05. The results of this study were as follows: 1. Peak GRF and relative time to peak GRF were not significantly different in the three different conditions (p>.05). 2. Onset time of four muscles, tibialis anterior, gastrocnemius, biceps femoris and rectus femoris, in the three different conditions were significantly different (p<.05). 3. The tibialis anterior and rectus femoris muscle activity before hip-off and tibialis anterior, gastrocnemius, and rectus fermoris muscle activity after hip-off were significantly different in the three different conditions (p<.05).

• 대한물리의학회지
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• 제9권4호
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• pp.347-354
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• 2014

PURPOSE: This study was to examine changes in muscle activity of lower extremity shoes sole form (high heels, shoes with curved out sole, house shoes). METHODS: The subjects of this study were 12 women in their twenties. They put three kinds of shoes (high heels, shoes with curved out sole, house shoes) and walked 5m. The muscles activities of lower extremity muscles (rectus femoris, vastus medialis, tibialis anterior, gastrocnemius medial part) were measured using a wireless electromyogram (EMG). Rectus femoris was attached to 1/2 position at the distance between ASIS and knee bone and vastus medials was attached to 2cm from upper inside of knee bone. Tibialis anterior was attached to 75% position above line connecting knee joint and ankle joint and gastrocnemius medial part was attached to 3 5% position above knee joint and ankle. RESULTS: It was found that there were significant differences in changes of muscles activities of lower extremity muscles (rectus femoris, vastus medialis, tibialis anterior, gastrocnemius medial part) on shoes sole forms (p<.05). All lower extremity muscles were showed high muscles activities, when high heels wear (p<.05). Wearing shoes with curved out sole was showed high muscle activity of tibialis anterior and lower muscle activity of gastrocnemius medial part compared with wearing house shoes (p<.05). CONCLUSION: Shoes sole form should be considered when patients with knee and ankle joint problems choose shoes because muscles were showed different activities according to shoes sole forms.

• Physical Therapy Rehabilitation Science
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• 제4권1호
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• pp.22-27
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• 2015

Objective: Jump training helps increase the muscle power by improving the muscle strength and reaction time of the muscle in operation. The purpose of this study was to identify the effects of strengthening, stretching exercise and meditation on electromyographic (EMG) onset timing of rectus femoris and gastrocnemius muscle during vertical jump performance. Design: Cross-sectional study. Methods: Ten healthy adults (5 male and 5 female) who were familiar with the vertical jumping task and had no lower extremity injuries or any bone or joint disorders, were recruited for this study. Muscle onset timing was measured by surface EMG. After EMG onset timing were measured during performing three baseline vertical jump trials, strengthening and stretching exercises of the rectus femoris and gastrocnemius, and meditation were performed in random order. EMG onset timing was measured during vertical jump after intervention, respectively. EMG value was averaged for the three trials and analyzed using one-way repeated ANOVA. Results: During vertical jump, EMG onset timing of gastrocnemius was a significant difference after intervention (p<0.05), and then there was significantly faster in strengthening exercise than meditation (p<0.05). Conclusions: These results indicate the potential positive effect of performing strengthening exercise of the gastrocnemius before a jumping event. Future research is required to identify the effects of intervention over a long period.

• 제어로봇시스템학회논문지
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• 제15권3호
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• pp.286-292
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• 2009

This paper proposes a knee-wearable robot system for assisting the muscle power of human knee by processing EMG (Electromyogram) signals. Although there are many muscles affecting the knee joint motion, the rectus femoris and biceps femoris among them play a core role in the extension and flexion motion, respectively, of the knee joint. The proposed knee-wearable robot system consists of three parts; the sensor for measuring and processing EMG signals, controller for estimating and applying the required knee torque, and actuator for driving the knee-wearable mechanism. Ultimately, we suggest the motion control method for knee-wearable robot system by processing the EMG signals of corresponding two muscles in this paper. Also, we show the effectiveness of the proposed knee-wearable robot system through the experimental results.

• 대한인간공학회지
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• 제30권5호
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• pp.613-619
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• 2011

Objective: The purpose of this study is to compare the muscle activities of lumbar and lower extremity muscles between left and right sides using EMG(Electromyogram) when patients are transferred by physical therapists. Background: Asymmetrical lift was recognized as a major cause of musculoskeletal disorder. Several studies show that physical therapists' transferring patients needs caution as it could cause a lumbar pain to patients but there is not sufficient data to support. Method: Forty healthy rehabilitation hospital physical therapists joined for this study. The subjects were transferred from wheelchair to treatment mat(from left to right) by connecting the EMG device to the patients' body both on erector spine and rectus fermoris. At the moment when subjects were being transferred, the EMG device collected data from both erector spine and rectus femoris and it was normalized as %MVC. Then the EMG data was statistically analyzed using paired t-tests. Results: The EMG data show that the left erector spinae and rectus femoris are more activated than right erector spinae and rectus femoris in all position(p<.05) in a significant degree. Conclusion: The result implies that physical therapists' asymmetrical lifting when patients are transferred by them has a potential cause of musculoskeletal disorder of patients. Further studies will be conducted to find out a same tendency in other muscles of a body and to see if there are other factors to affect to patients during asymmetrical lifting. Application: These results can be used to provide baseline information for more understanding to asymmetrical lift loading.

• 대한정형도수물리치료학회지
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• 제17권1호
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• pp.29-34
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• 2011

Background: The purpose of this study was to investigate the effect of a Kinesio taping on muscle power and fatigue index in quadriceps femoris (vastus medialis, vastus lateralis, rectus femoris.). Methods: 15 male (heathy collegiate students) was enrolled from Kyungwoon university, Gumi. Kinesio tape was applied on quadriceps femoris muscle of subjects. Muscle power and fatigue index was measured by Wingate ergometer (warm-up was 30sec in 60W, maximum power test was 30sec in 100W, recovery was 30sec in 60W) in pre- and post applied taping. Results: As a results, there showed statistically significant improvement in mean power, peak power, mean power/kg, peak power/kg, fatigue index (p<.05). Conclusions: The study of Wingate test by applying Kinesio taping was significantly effected in mean power, peak power, mean power/kg, peak power/kg.