• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.75-83
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• 2006

The purpose of this study was to investigate steady-state force depression following active muscle shortening in human tibialis anterior muscle during voluntary contractions. Subjects (n = 7; age $24{\sim}39$ years; 7 males) performed isometric reference contractions and isometric-shortening-isometric contractions, using maximal voluntary effort. Force depression was assessed by comparing the steady-state isometric torque produced following active muscle shortening with the purely isometric reference torque obtained at the corresponding joint angle. In order to test for effects of the shortening conditions on the steady-state force depression, the speed of shortening were changed systematically in a random order but balanced design. Ankle dorsiflexion torque and joint angle were continuously measured using a dynamometer. During voluntary contractions, muscle activation of the tibialis anterior and the medical gastrocnemius was recorded using surface electromyography. Force depression during voluntary contractions, with a constant level of muscle activation, was 12 %, on average over all subjects. Force depression was independent of the speeds of shortening ($13.8{\pm}2.9%$, $10.3{\pm}2.6%$ for 15 and 45 deg/sec over 15 deg of shortening, respectively). The results of this study suggest that steady-state force depression is a basic property of voluntarily-contracting human skeletal muscle and has functional implication to human movements.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.9 no.1
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• pp.35-39
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• 2011

Purpose : The purpose of this study was to determine changes in muscle activity due to elastic taping at the rectus femoris, biceps femoris and tibialis anterior muscles using surface electromyography analysis. Methods : In this study 10 healthy university students in the Department of Taekwondo Studies were screened and individuals with a history of previous injury or surgery to their nerve, muscle, and skeletal systems, such as paresthesia and motor disorder, were excluded. Subjects were taped over the rectus femoris, biceps femoris, and tibialis anterior and their muscle activities were analyzed using the surface electromyography method during maximal voluntary isometric contraction. Results : The results of this study were as follows: muscle activities indicated a significant increase after elastic taping than before at the rectus femoris, biceps femoris, and tibialis anterior muscle. These results lead us to the conclusion that muscle activity were influenced by elastic taping at the rectus femoris, biceps femoris, and tibialis anterior muscles. Conclusion : The results of this study show that muscle activity can be improved by elastic taping at the lower limbs. These results suggest that elastic taping of muscles in the lower extremities has the capability to increase muscle activity in the body.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.9 no.2
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• pp.25-30
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• 2011

Purpose : This study aims to examine the changes of muscle activity of the tibialis anterior muscle and the gastrocnemius muscle on the ground and unstable ground for functional reach test. Methods : This study chose 24 elderly men and 24 elderly women who could walk independently, reach their arm over 25 cm, show shoulder joint $90^{\circ}$ flexion, had no operations on lower limb joints, and don't take medication affecting the ability to keep balance. Muscular activity of the tibialis anterior muscle and the gastrocnemius muscle was measured using functional reach test and electromyogram. Functional reach test was conducted at a total of four sections, 0cm, 15cm, 20cm, and 25cm. Results : It was known that the gastrocnemius muscle was used more than the tibialis anterior muscle to keep balance and the elderly with good balance ability showed no great change of muscular activity on both the stable and unstable ground. Conclusion : It was found that the subjects used their gastrocnemius muscle more and lower limbs of frequently used parts to keep their balance. As the elderly have good balance ability, they showed no great change of muscular activity on both the stable and unstable ground.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.11 no.1
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• pp.21-29
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• 2013

Purpose : The purpose of this study was to determine the changes in ultrasound imaging of the lower limbs in patients with degenerative osteoarthritis who received a total knee replacement (TKR). Methods : The participants for the study were ten patients who were to receive a total knee replacement. Measurements were taken a total of three times: before receiving a total knee replacement, and one week and two weeks after receiving a total knee replacement. The vastus medialis, rectus femoris muscle, tibialis anterior and gastrocnemius muscle were measured using ultrasound imaging. Results : Muscle thickness of the vastus medialis, rectus femoris muscle, tibialis anterior and gastrocnemius muscle had no significant interaction over time whether surgery was performed or not. White area index (WAI) and density of vastus medialis, rectus femoris muscle, tibialis anterior and gastrocnemius muscle had no significant interaction over time whether surgery was performed or not. Conclusion : In conclusion, lower quality muscles were due to a decrease in muscle fiber and an increase in fat fiber. Therefore, initial physical therapy after total knee replacement should consider this point and be designed appropriately as a therapeutic approach for total knee replacement patients.

• PNF and Movement
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• v.12 no.3
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• pp.173-179
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• 2014

Purpose: The purpose of this study is to analyze the effect of arm leg flexion patterns of proprioceptive neuromuscular facilitation on the muscle activation of the contralateral lower extremity. Methods: In this study, Electromyogram MP150(Biopac system, USA) was applied to 20 healthy male subjects. Unilateral arm flexion- abduction- external rotation pattern and Unilateral leg flexion- adduction- external rotation with knee flexion pattern were applied within mid range of the supine position for measurement. The muscle activation of vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius(medialis) muscle of the contralateral lower extremity were compared and analyzed during the applications. Results: The results of this study were summarized as follows: There was a statistically significant difference in the muscle activation of vastus lateralis and biceps femoris between the arm and leg patterns(P<0.05). There was a statistically significant difference in the muscle activation of gastrocnemius and tibialis anterior between the arm and leg patterns(P<0.05). Conclusion: contralateral vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior muscles show the higher muscle activation in the leg pattern than one in the arm pattern.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.277-286
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• 2011

Purpose : This study was to investigate the prevention of spasticity with modified Ashworth scale(MAS) and range of motion(ROM) increase with goniometer in ankle joint by functional electrical stimulation(FES) and exercise for 4 weeks in chronic stroke patients. Methods : 60 chronic stroke patients participated in this study. The subjects were divided into 3 groups, FES group(n=20), FES+exercise group(n=20) and control croup(n=20). After FES application on tibialis anterior muscle by 35Hz for 4 weeks, the change of ankle joint movement was measured by goniometer. Results : The spasticity in ankle joint was decreased greatly in FES and FES+excercise groups(p<.05), and the ROM of ankle joint was increased greatly in FES and FES +exercise groups(p<.05) than control group(p>.05). Conclusion : It shows that FES made the angle of dorsiflexion in spastic ankle joint increase with functional improvement of tibialis anterior muscle in chronic stroke patients. This show that the FES is avaliable for facilitation of ROM and decrease of spasticity as a therapeutic tool.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.31-46
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• 2002

The purpose of this research is to provide scientific training guides and the basis for preventing injuries in performing tango backward walk by comparing the effects the height and shape of a heel will have on leg muscles and determining the difference between skilled and unskilled dancers through EMG analysis according to different types of shoes Total eight female athletes were selected for this research. Four with six years of professional dancing experience and another four with one year of dance sports experience. Utilizing the EMG system, rectus femoris, biceps femoris, anterior tibialis, gastrocnemius were measured under different heights (0cm, 5cm, 7cm, 9cm) and shapes (flat, fine, wide) of a heel. Experiments were conducted calculating EMG peak value and muscle load ration under different types of shoes in order to analyze the EMG of leg muscles and Erector Spinae when performing tango backward walk. The result was as follows: 1. The EMG peak value of leg muscles showed significant difference under different heights of a heel in anterior tibialis(p<.001) and gastrocnemius(p.<01) in case of skilled dancers, and in biceps femoris(p.<01) in case of unskilled dancers. 2. The EMG peak value of leg muscles showed significant difference under different shapes of a heel in anterior tibialis(p<.001) and gastrocnemius(p<.001) in case of skilled dancers, and showed no significant difference in case of unskilled dancers. 3. The muscle load ration of leg muscles showed different degrees of muscle contribution between skilled and unskilled dancers. The muscle load ration was in the order of anterior tibialis, rectus femoris, biceps femoris, and gastrocnemius in case of skilled dancers and anterior tibialis, gastrocnemius, biceps femoris, and rectus femoris in case of unskilled dancers.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.1
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• pp.103-108
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• 2011

Purpose : The purposes of this study were to compare the muscle activity ratio of tibialis anterior (TA) / extensor digitorum longus (EDL) during the active ankle dorsiflexion in subjects with the normal toe (NT) and the hammer toe (HT). Methods : Nineteen subjects with the NT group and nineteen subjects with the HT group were recruited for this study. The muscle activities of TA and EDL were measured by using surface electromyography (EMG) and the angles of ankle dorsiflexion and eversion of the subtalar joint were measured by using 3-dementional motion analysis during the active ankle dorsiflexion in prone position. Results : The muscle activity ratio of TA / EDL was significantly lower in the HT group compared to the NT group (p<.05). The angle of ankle dorsiflexion was significantly lower in the HT group compared to the NT group (p<.05). Conclusions : These results suggest that muscle imbalance between TA and EDL muscle and decreased ankle dorsiflexion range of motion may contribute to hammer toe deformity. Further studies are needed to confirm that the correcting of this imbalance and the increasing ankle dorsiflexion could improve toe alignment in the subjects with HT.

• PNF and Movement
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• v.13 no.2
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• pp.95-102
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• 2015

Purpose: The purpose of this study was to analyze the effect of arm flexion patterns of proprioceptive neuromuscular facilitation on muscle activation in the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used. Methods: This study used an electromyogram (MP150, Biopac Systems, USA) to measure muscle activation in 20 healthy male students. Comparative analysis was completed on muscle activation of the vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius of the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used with a unilateral arm flexion-abduction-external rotation pattern. Paired t-tests using the SPSS 12.0 for Windows analyzed the data produced by the electromyogram. Results: There was a statistically significant difference in muscle activation in the biceps femoris, gastrocnemius, and tibialis anterior when the open kinematic chain and closed kinematic chain positions were compared (p < 0.05). Conclusion: The biceps femoris, gastrocnemius, and tibialis anterior muscles showed greater muscle activation in the closed kinematic chain position when compared to the open kinematic chain position.

• PNF and Movement
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• v.9 no.1
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• pp.47-54
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• 2011

Purpose : The purpose of this study was to investigate muscle activity of affected lower extremity by unaffected lower extremity exercise and tried to examine muscle activity of affected lower extremity of hemiplegic patients were caused by stroke according to wearing single strap hemisling or non-wearing. Methods : We measured muscle activity of affected lower extremity when wearing single strap hemisling to affected lower extremity or non-wearing according to unaffected lower extremity used MP 150 Eletromyogram. Results : 1) Muscle activity of gluteus medius muscle was the highest D1 before wearing single strap hemisling. 2) Muscle activity of hamstring muscle was the highest D3 after wearing single strap hemisling. 3) Muscle activity of quadriceps muscle was the highest D5 after wearing single strap hemisling. 4) Muscle activity of tibialis anterior muscle was the highest D1 after wearing single strap hemisling. 5) Muscle activity of soleus muscle was the highest D2 before wearing single strap hemisling. Conclusion : Wearing single strap hemisling of hemiplegic patients had effect on muscle activity of gluteus medius but didn't effect gluteus medius, hamstring, quadriceps, tibialis anterior muscle and soleus muscle.