• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.593-601
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• 2009

The goal of this study was to investigate the lower extremity's coordination determined by temporal relations with increasing high-heel (3, 7, 9cm) while walking on a treadmill. Twelve healthy women who walked on a treadmill under three conditionswearing 3cm high-heel shoes, 7cm, and 9cm-while kinematic data were collected using a six-cameras (240Hz) Qualisys ProReflex System. From these data, knee flexion, tibia internal rotation, and foot eversion were calculated in Euler technique and found the time for occurring the maximum angle of these movements. The maximum angle of these movements occurred almost simultaneously in 3cm high-heel walking, but not in 7cm and 9cm. The ratio of time for maximum angle of the foot eversion to tibia internal rotation converged to 1 in 3cm high-heel walking, but were less than 1 in 7cm and 9cm. In conclusion, it was indicated that 3cm high-heel walking had better the lower extremity's coordination compared with 7, 9cm high-heel walking.

• Physical Therapy Rehabilitation Science
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• v.9 no.1
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• pp.10-17
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• 2020

Objective: Hallux valgus (HV) is a common musculoskeletal deformity that is accompanied with pain and continues to decrease one's quality of life and ability to perform daily life activities by affecting gait and static stability. Therefore, this study aimed to investigate the effect of the angle of HV (HVA) and to compare the one-legged stance and gait parameters in young adults with less HV and severe HV. Design: Cross-sectional study. Methods: Forty young adults were divided into two groups, where HVA ≥15° (n=20) was defined as HV, and HVA <15° (n=20) was defined as normal. For balance ability, the center of pressure (COP) path, velocity, length of axis of the COP path, deviation of the x-axis and y-axis, and percentage of foot pressure were measured, and gait, the foot rotation angle, step length, percentage of each phase of the gait cycle, time change from the heel to forefoot, and maximum pressure of the forefoot and midfoot were measured. Results: Significant differences were found in sway length and time change from heel to forefoot during walking between the normal and HV groups (p<0.05). Most parameters were not associated with the HVA, but parameters such as length of axis and time to change from heel to forefoot were significantly associated with the HVA (p<0.05). Conclusions: These results suggest that most one-legged stance and gait parameters were not significantly affected by the HVA in young adults; therefore, future studies are needed in order to address other dynamic parameters and other methods of gait analysis for detecting clinically meaningful conditions.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.117-123
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• 2013

The purpose of this study was to provide data to increase the success rate of penalty kicks through quantifying the shape of skilled kicks by performing a kinematic analysis on the change of movement during the kicking phase which the goalkeeper uses as a vital clue. Three high definition video cameras(GR-HD1KR, JVC, Japan) were used for the study and 18 reflective markers were attached to the body joints. Corners of the goal, difficult for goalkeepers to block, were set as aims and 1 m by 1.2 m targets were installed. Each subject had five sets of kicks at random, and the analysis was done on the movements that hit the target. Time, speed of the right lower limb's center of mass, joint angle, and angular velocity were chosen as factors and the results of the analysis showed statistical significance. The player taking a penalty kick should train to avoid leaning one's body towards the kicking direction and change the angle of the right foot right before the impact to decide the direction of the ball. The goalkeeper can increase the save success rate by studying the angle of the kicker's body and the right foot as well as the timing of the kick.

• Physical Therapy Korea
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• v.28 no.2
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• pp.108-116
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• 2021

Background: Whole-body vibration (WBV) has been used to alleviate proprioceptive damage by musculoskeletal and neurological conditions. However, no study has determined whether wearing shoes while applying WBV can affect proprioception precision of the knee joint. Objects: This study aimed to determine the differences in the proprioceptive precision of the knee joint before and after WBV and to compare the proprioceptive precision of the knee joint between barefoot and shoe-wearing conditions. Methods: This study recruited 33 healthy participants. A passive-to-active angle reproduction test was used to measure the proprioception precision of the knee joint using an electrogoniometer, and the target angle was set to a knee flexion of 30°. Proprioception precision was calculated using the error angle (angular difference from 30°). Proprioceptive precision was measured in weight-bearing and non-weight-bearing positions before and after applying WBV for 20 minutes at 12 Hz in barefoot and shoe-wearing conditions. Mixed repeated analysis of variance was used to determine the differences in changes in the proprioceptive precision of the knee joint according to foot conditions. Results: There were significant improvements in the weight-bearing (p = 0.002) and non-weight-bearing (p < 0.001) proprioceptive precision of the knee joint after applying WBV. However, there was no significant difference in the change in proprioceptive precision of the knee joint after applying WBV between the barefoot and shoe-wearing conditions. Conclusion: WBV stimulation had an immediate effect on improving the proprioceptive precision of the knee joint. However, foot conditions (barefoot or shoe-wearing) during WBV application did not influence the proprioceptive precision of the knee joint.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.100-105
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• 1994

In this paper, we discuss a method for design of an ambulance stretcher which call decrease blood pressure fluctuation caused by ambulance acceleration. Recently, a lot of stretchers which can isolate the vertical vibration to reduce body resonances (4-10 Hz) have been used during ambulance transport. However, we have found that blood pressure of a patient laying in the stretcher fluctuates when the ambulance accelerates or decelerates. Since the enforced change of the blood pressure may deteriorate the patent's condition, a stretcher to cancel head-to-foot acceleration and to decrease the blood pressure variation (BPV) is expected for safe transport. We propose a method to design a stretcher which is tilted according to an adequate angle to cancel head-to-foot acceleration by gravity when the ambulance accelerates or decelerates. A control method of the stretcher is constructed by means of simulation analysis using acceleration data measured during ambulance transport. It is confirmed that the active controlled stretcher proposed has good performance for the BPV reduction.

• Journal of Korean Foot and Ankle Society
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• v.17 no.2
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• pp.79-83
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• 2013

Calcaneus is largest tarsal bone and the fracture of calcaneus is most common tarsal fractures. Calcaneal fractures are divided into extra-articular and intra-articular fractures. Intra-articular calcaneal fractures could be classified as tongue type and joint depression type using simple lateral radiograph (Essex-Lopresti classification), but Sanders suggested new classification according to involving the posterior facet of calcaneus using computed tomography. The involvement of posterior facet was revealed as more complicated than Essex-Lopresti classification. The principle purpose of treatment of calcaneal fractures are restoration of calcaneal height (B$\ddot{o}$hler angle), width, axis, anatomical reduction of joint and restoration of function through the stable fixation. Good visualization of joint and anatomical reduction could be achieved by extended lateral approach. But, skin problem could be occurred after of extended lateral approach.

• Journal of Korean Foot and Ankle Society
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• v.4 no.1
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• pp.23-29
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• 2000

Acquired Hallux varus is defined radiographically by a negative metatarsophalangeal angle and clinically by adduction of the hallux on the first metatarsal and most commonly occurs after hallux valgus surgery. It's the prevalence has ranged from 2% to 17%. We report a case of hallux varus resulted from weakening of support of lateral soft tissue and resection of an excessive amount of the metatarsal head during a bunionectomy after initial correction of hallux valgus. We corrected the hallux varus deformity using transfer of extensor hallucis brevis tendon with reconstruction os lateral capsule.

• Journal of Korean Foot and Ankle Society
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• v.4 no.1
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• pp.48-54
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• 2000

Haglund's syndrome produces retrocalcaneal bursitis or achilles tendinitis due to impingement of posterior superior bursal projection of calcaneus on insertional fibers of achilles tendon. Haglund's syndrome has been mainly associated with wearing rigid counter shoes and with athletes. We experienced three case of late sequelae of secondary Haglund's syndrome after malunion of tongue type calcaneus fracture. It is to be the first description of secondary Haglund's syndrome after calcaneus malunion and also the first report as the late complication of calcaneus fractures. Three cases were all tongue type intraarticular fractures and were treated with $45^{\circ}$ superior angle resection of superior calcaneal tuberosity. Clinical results by modified Rowe score were excellent with complete pain relief for all three cases.

• Journal of Korean Foot and Ankle Society
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• v.21 no.2
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• pp.50-54
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• 2017

The goal of surgical correction for hallux valgus is to achieve a painless, shoe-wearable, and relatively straight toe with a balanced joint motion that results in aesthetically and functionally satisfactory toe. To date, there has not been a consensus on the ultimate surgical procedure for hallux valgus correction. Unfortunately, such a consensus may be difficult since it is not uncommon to encounter complications after hallux valgus correction. Postoperative soft tissue complications include difficult wound healing, infection, hypertrophy, or pain of the scar, joint stiffness, and tendon or sensory nerve damage. Postoperative bony complications include malunion, nonunion, failure of fixation, failure of angle correction, recurred deformity, osteomyelitis, and failure of balance between the metatarsal heads. Herein, we review common complications after surgical correction of hallux valgus, such as stiff joint, bony complications, recurrence of the deformity, and hallux varus.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.203-209
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• 2009

The purpose of this study is to develop a minimally constraint joint angle measurement system for the feedback control of FES (functional electrical stimulation) locomotion. Feedback control is desirable for the efficient FES locomotion, however, the simple on-off control schemes are mainly used in clinic because the currently available angle measurement systems are heavily constraint or cosmetically poor. We designed a new angle measurement system consisting of a magnet and magnetic sensors located below and above the ankle joint, respectively, in the rear side of ipsilateral leg. Two magnetic sensors are arranged so that the sensing axes are perpendicular each other. Multiple positions of sensors attachment on the shank part of the ankle joint model and also human ankle joint were selected and the accuracy of the measured angle at each position was investigated. The reference ankle joint angle was measured by potentiometer and motion capture system. The ankle joint angle was determined from the fitting curve of the reference angle and magnetic flux density relationship. The errors of the measured angle were calculated at each sensor position for the ankle range of motion (ROM) $-20{\sim}15$ degrees (dorsiflexion as positive) which covers the ankle ROM of both stroke patients and normal subjects during locomotion. The error was the smallest with the sensor at the position 1 which was the nearest position to the ankle joint. In case of human experiment, the RMS (root mean square) errors were $0.51{\pm}1.78(0.31{\sim}0.64)$ degrees and the maximum errors were $1.19{\pm}0.46(0.68{\sim}1.58)$ degrees. The proposed system is less constraint and cosmetically better than the existing angle measurement system because the wires are not needed.