• The Korean Journal of Physiology and Pharmacology
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• v.27 no.5
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• pp.481-491
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• 2023

The β subunits of high voltage-gated calcium channels (HGCCs) are essential for optimal channel functions such as channel gating, activation-inactivation kinetics, and trafficking to the membrane. In this study, we report for the first time the potent blood pressure-reducing effects of peptide fragments derived from the β subunits in anesthetized and non-anesthetized rats. Intravenous administration of 16-mer peptide fragments derived from the interacting regions of the β1 [cacb1(344-359)], β2 [cacb2(392-407)], β3 [cacb3(292-307)], and β4 [cacb4(333-348)] subunits with the main α-subunit of HGCC decreased arterial blood pressure in a dose-dependent manner for 5-8 min in anesthetized rats. In contrast, the peptides had no effect on the peak amplitudes of voltage-activated Ca²⁺ current upon their intracellular application into the acutely isolated trigeminal ganglion neurons. Further, a single mutated peptide of cacb1(344-359)-cacb1(344-359)_K357R-showed consistent and potent effects and was crippled by a two-amino acid-truncation at the N-terminal or C-terminal end. By conjugating palmitic acid with the second amino acid (lysine) of cacb1(344-359)_K357R (named K2-palm), we extended the blood pressure reduction to several hours without losing potency. This prolonged effect on the arterial blood pressure was also observed in non-anesthetized rats. On the other hand, the intrathecal administration of acetylated and amidated cacb1(344-359)_K357R peptide did not change acute nociceptive responses induced by the intradermal formalin injection in the plantar surface of rat hindpaw. Overall, these findings will be useful for developing antihypertensives.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.1-7
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• 2005

Excessive pronation and impact force during running are related to various running injuries. To prevent these injuries, three type of running shoes are used, such as cushioning, stability, and motion control. Although there were may studies about the effect of midsole hardness on impact force, no study to investigate biomechanical effect of motion control running shoes. The purpose of this study was to determine biomechanical difference between cushioning and motion control shoes during treadmill running. Specifically, plantar and rearfoot motion, impact force and loading rate, and insole pressure distribution were quantified and compared. Twenty male healthy runners experienced at treadmill running participated in this study. When they ran on treadmill at 3.83 m/s. Kinematic data were collected using a Motion Analysis eight video camera system at 240 Hz. Impact force and pressure distribution data under the heel of right foot were collected with a Pedar pressure insole system with 26 sensors at 360 Hz. Mean value of ten consecutive steps was calculated for kinematics and kinetics. A dependent paired t-test was used to compare the running shoes effect (p=0.05). For most kinematics, motion control running shoes reduced the range of rearfoot motion compared to cushioning shoes. Runners wearing motion control shoe showed less eversion angle during standing less inversion angle at heel strike, and slower eversion velocity. For kinetics, cushioning shoes has the effect to reduce impact on foot obviously. Runners wearing cushioning shoes showed less impact force and loading rate, and less peak insole pressure. For both shoes, there was greater load on the medial part of heel compared to lateral part. For pressure distribution, runners with cushioning shoes showed lower, especially on the medial heel.

• PNF and Movement
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• v.19 no.2
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• pp.233-242
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• 2021

Purpose: The purpose of this study was to determine the changes in foot contact area and pressure when walking with a functional insole that emphasizes the Hallux point as compared to a general insole. Methods: In this study, an experiment was conducted to investigate changes in plantar pressure and contact area for a functional insole that emphasized the Hallux point as compared to a general insole. A lower extremity robot was used for walking reproduction. First, the gait sequence according to the two insoles was determined through a randomized controlled trial comparison. According to the sequence procedure, the insole was attached to the shoe and then worn on the right side of the lower extremity robot for gait reproduction at a normal gait speed of 20 steps per minute. After programming the robot to walk, the experiment was carried out. The result value was determined by averaging the pressure and area data of the fore and rear foot measures after walking at 20 steps per minute. Results: The functional insole that emphasized the hallux point significantly increased the forefoot and rearfoot contact area (p < 0.05) and significantly decreased the forefoot and rearfoot contact pressure (p < 0.05) compared to the general insole. Conclusion: A functional insole that emphasizes the hallux point does not collapse the medial longitudinal arch during gait, increasing foot stability and reducing fatigue. Thus, this functional insole needs to be widely used clinically.

• Physical Therapy Korea
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• v.30 no.2
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• pp.110-119
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• 2023

Background: Osteoarthritis is a common condition with an increasing prevalence and is a common cause of disability. Osteoarthritic pain decreases the quality of life, and simple gait training is used to alleviate it. Knee osteoarthritis limits joint motion in the sagittal and lateral directions. Although many recent studies have activated orthotic research to increase knee joint stabilization, no study has used patellar tendon straps to treat knee osteoarthritis. Objects: This study aimed to determine the effects of patellar tendon straps on kinematic, mechanical, and electromyographic activation in patients with knee osteoarthritis. Methods: Patients with knee osteoarthritis were selected. After creating the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), leg length difference, Q-angle, and thumb side flexion angle of the foot were measured. Kinematic, kinetic, and muscle activation data during walking before and after wearing the orthosis were viewed. Results: After wearing the patellar tendon straps, hip adduction from the terminal stance phase, knee flexion from the terminal swing phase, and ankle plantar flexion angle increased during the pre-swing and initial swing phases. The cadence of spatiotemporal parameters and velocity increased, and step time, stride time, and foot force duration decreased. Conclusion: Based on the results of this study, the increase in plantar flexion after strap wearing is inferred by an increase due to neurological mechanisms, and adduction at the hip joint is inferred by an increase in adduction due to increased velocity. The increase in cadence and velocity and the decrease in gait speed and foot pressure duration may be due to joint stabilization. It can be inferred that joint stabilization is increased by wearing knee straps. Thus, wearing a patellar tendon strap during gait in patients with knee osteoarthritis influences kinematic changes in the sagittal plane of the joint.

• The Journal of Korean Physical Therapy
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• v.23 no.5
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• pp.1-5
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• 2011

Purpose: This study was designed to investigate the changes of postural sway and muscle activation while standing upright and performing a dual task. Methods: Nine healthy adults were recruited and provided their written informed consent. They performed a balance task with and without a cognitive task on a force flatform (Good balance, Metitur Ltd., Filand). Postural sway was measured as medio-lateral and anterior-posterior distance and the velocity of the center of pressure and muscle activations of the ankle dorsi- and plantar-muscle was measured. The recruits completed three trials and the data was analyzed by a paired t-test. Results: There were significant differences in the medio-lateral and anterior-posterior distance and the velocity of the center of pressure, and significant increases in the muscle activities of the tibialis anterior. Conclusion: These findings revealed that performing a dual task increases postural sway and muscle activation of the ankle when simultaneously maintaining balance and performing another cognitive task. Future studies should focus on balance training with a dual task for patients.

• Korean Journal of Applied Biomechanics
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• v.23 no.3
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• pp.235-243
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• 2013

The purpose of this study was to analyse scientific according to period of rehabilitation training of ACL patients. ACL patients seven subjects participated in this study. Gait (1.58 m/sec) analysis was performed by using a 3-D Cinematography, a Zebris system and a electromyograph system. The data were analyzed by paired t-test. The joint angles were recorded from the ankle, knee, hip joints. Peak max dorsi-flexion and peak max plantar-flexion identified significant differences (p<0.05). Another angles were no significant difference. Vertical force (Fz) and max pressure variables improved 6 month RTP better than 3 month RTP. EMG were collected from 4 muscles (rectus femoris, biceps femoris, gastrocnemius, tibialis anterior) with surface electrides in gait system. EMG signals were rectified and smoothed data. EMG signas were no significant difference but they also improved 6 month RTP better than 3 month RTP. More research is necessary to determine exactly what constitutes optimal rehabilitation training period for ACL patients.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.3
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• pp.21-27
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• 2021

PURPOSE: This study examined the relationship between the severity of a hallux valgus (HV) deformity and the kinetic three-dimensional ground reaction force (GRF) through a motion analysis system with force platforms in individuals with a HV deformity during normal speed walking. METHODS: The participants were 36 adults with a HV deformity. The participants were asked to walk on a 6 m walkway with 40 infrared reflective markers attached to their pelvic and lower extremities. A camera capture system and two force platforms were used to collect kinetic data during gait. A Vicon Nexus and Visual3D motion analysis software were used to calculate the kinetic GRF data. RESULTS: This research showed that the anterior maximal force that occurred in the terminal stance phase during gait had a negative correlation with the HV angle (r = -.762, p < .01). In addition, the HV angle showed a low negative correlation with the second vertical maximal force (r = .346, p < .05) and a moderate positive correlation with the late medial maximal force (r = .641, p < .01). CONCLUSION: A more severe HV deformity results in greater abnormal translation of the plantar pressure and a significantly reduced pressure force under the first metatarsophalangeal joint.

• Annual Conference of KIPS
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• 2017.04a
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• pp.1064-1065
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• 2017

트레드밀 인터페이스는 사용자의 보행 모션을 인식하여 가상세계를 네비게이션 할 수 있는 보행 플랫폼이다. 특히 작은 보행 영역을 가지는 트레드밀의 경우, 보행자 속도 예측 방법에 의해 더욱 효과적인 지면 모션의 생성이 가능하다. 본 연구에서는 착용형 압력 센서로 부터 측정되는 족부 압력 데이터를 기반으로 하는 보행속도 예측 방법과 트레드밀 제어 방법을 제시하고자 한다. 속도 예측은 지면 반발력 데이터 중 압력중심의 변화 속도를 통해 도출되며, 예측된 속도를 트레드밀 속도 제어에 안정적으로 적용하기 위한 피드포워드 제어 방법을 제시한다. 또한 족부 압력 데이터 측정이 가능한 자율 제어 트레드밀 시스템 구현과 보행 실험 과정을 소개한다.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.11 no.1
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• pp.33-40
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• 2016

Objectives : To evaluate the foot indices using dynamic and static checking on healthy adult people. Methods : Foot indices analysis was performed for 46 students. Static checking practiced for Foot Pressure(FP) and Toe Pressure Difference(TPD) and dynamic checking was used for Vertical Axis Angle(VAA). Results : On gender, there was generally no statical significant difference, except RFP(Right Foot Pressure). The RFP of male was bigger than that of female. On age, in addition, there was similar tendency, only RFP had a positive correlation (r=0.35, p<0.05). Comparing foot indices on right and left, we found TPD and VAA had a tendency of pronation on left, but FP had a opposite tendency. On consistency of each foot index, discrepancy between TPD and VAA (39.47%) was lesser than combination of the others. Conclusions : According to foot indices among 46 healthy student, we found out that there is partially correlation between dynamic and static checking. We hope that the data we found will contribute to standardization of podiatry indices which provide medical guidance for cure of foot disease, supporting further podiatry research.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.2
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• pp.654-670
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• 2020

Workers at construction sites are easily exposed to many dangers and accidents involving falls, tripping, and missteps on stairs. However, researches on construction site monitoring system to prevent work-related injuries are still insufficient. The purpose of this study was to develop a wearable textile pressure insole sensor and examine its effectiveness in managing the real-time safety of construction workers. The sensor was designed based on the principles of parallel capacitance measurement using conductive textile and the monitoring system was developed by C# language. Three separate experiments were carried out for performance evaluation of the proposed sensor: (1) varying the distance between two capacitance plates to examine changes in capacitance charges, (2) repeatedly applying 1 N of pressure for 5,000 times to evaluate consistency, and (3) gradually increasing force by 1 N (from 1 N to 46 N) to test the linearity of the sensor value. Five subjects participated in our pilot test, which examined whether ascending and descending the stairs can be distinguished by our sensor and by weka assessment tool using k-NN algorithm. The 10-fold cross-validation method was used for analysis and the results of accuracy in identifying stair ascending and descending were 87.2% and 90.9%, respectively. By applying our sensor, the type of activity, weight-shifting patterns for balance control, and plantar pressure distribution for postural changes of the construction workers can be detected. The results of this study can be the basis for future sensor-based monitoring device development studies and fall prediction researches for construction workers.