• 대한물리치료과학회지
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• 제27권3호
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• pp.67-74
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• 2020

Background: The purpose of this study was to investigate the change of lower limb muscle activation according to the use of arm sling in normal subjects. Design: Cross-sectional Study Methods: Seven healthy subjects (6 males and 1 female, 25.42 years, 173.57 cm, 71.71 kg) were recruited on a voluntary basis. To measure the lower limb muscle activation during walking with and without arm sling, we used a wireless surface electromyography (sEMG) (FreeEMG1000, BTS Bioengineering, Milano, Italy). Six wireless sEMG electrodes were attached to the following three major muscle groups of the both side lower limb: rectus femoris, biceps femoris, medial gastrocnemius. All subjects wore arm sling on their right side during measurement. Results: In the stance phase, there was a significant increase in right side rectus femoris muscle activation in walking without arm sling compared to the walking with arm sling (p<.05). Additionally, In the stance phase, there was a significant increase in left side tibialis anterior muscle activation in walking without arm sling compared to the walking with arm sling (p<.05). Conclusion: The results of this study suggest that there is a significant association between the arm swing restriction and lower limb muscle activation. Therefore, it seems that it can be applied as basic data for gait training with an arm slings.

• The Journal of Korean Physical Therapy
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• 제10권1호
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• pp.127-138
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• 1998

This study was carried out tn invstigate and compare biomechanical characteristics during free speed gait in hemiplegic patients after stroke who took therapeutic exercise by analyzing kinematic and kinetic data in the sagital plane and electromyographic data. Six patients($41\~69$ years old) and age-matched six volunteers in good health(51-61 years old) wire studied. The patients were sorted into two groups, depending on their self-speed of walking : fast speed group(3 patients) and slow speed group(3 patients). The results were as fellows. : 1. In spatio-temparal parameters, affected and unaffected side of fast group showed symetry but blew group showed asymetry of single limb support, opposite foot contact and stance phase (p<0.05). Compared with normal group, patient group showed slower velocity, shoter stride length and longer double limb support (p<0.05). 2. In the pelvic anterior tilt, patient group showed lower valued than normal group. It. In the ground reaction force-vertical force, fast group showed similar double peak gragh compared with normal group, butvslow group showed lower values without double peak (p<0.05).

• The Journal of Korean Physical Therapy
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• 제22권3호
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• pp.49-53
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• 2010

Purpose: The purpose of this study was to investigate the plantar pressure distribution between the affected and unaffected side in adult hemiplegia during gait with the use of a quad-cane. Methods: Thirty-four stroke patients from 34 to 83 years of age were enrolled in this study, and in random order, all patients were asked to walk at their most comfortable speed three times along a walkway with the use of quad-cane over a period of three days. Plantar pressure distribution was measured with regard to foot contact pattern and center of pressure (CoP) trajectories during the stance phase, progressing from heel-strike to toe-off. The F-scan system was used to compare the foot pressure of the affected and unaffected sides. Results: A significant reduction in the total contact area, the width of fore foot (FF) and hind foot (HF), and anterior/posterior (AP) CoP trajectory of the affected side was found. However, contact pressure of the hind foot on the affected side during walking increased when compared to that on the unaffected side. Conclusion: We demonstrated that plantar pressure distribution on the affected side of adult hemiplegia patients was generally poorer than that on the unaffected side when these patients walked with cane assistance. However, the use of a quad-cane was shown to increase contact pressure of the hind foot on the affected side because weight can be borne on the affected side during heel-strike with use of the cane.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1993년도 춘계학술대회논문집
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• pp.1-9
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• 1993

A human gait study is required for the biomechanical design of running shoes. A tow-dimensional dynamic model was developed in order to analyze lower extremity kinematics and loadings at the right ankle, knee, and hip joints. The dynamic model consists of three segments, the upper leg, the lower leg, and the foot. Each segment was assumed to be a rigid body with one or two frictionless hinge joints. The lower extremity motion was assumed to be planar in the sagittal plane. A young male subject was involved in the gait test and his anthropometric data were measured for the calculation of segement mass and moment of inertia. The experimental data were obtained from three trials of walking at 1.2m/s. The foot-floor reaction data were measured from a Kistler force plate. The kinematic data were acquired using a three-dimensional motion measurement system (Expert Vision) with six markers, five of which were placed on the right lower extremity segments and the rest one was attached to the force plate. Based on the model and experimental data for the stance phase of the right foot, the calculated vertical forces reached up to 492, 540, and 561 N at the hip, knee, ankle joints, respectively. The flexion-extension moments reached up to 155, 119, and 33 Nm in magnitude at the corresponding joints.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 추계학술발표대회
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• pp.429-431
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• 2022

하지 웨어러블 로봇의 근력 보조 성능을 극대화하기 위해서는 착용자의 보행 상태를 인식하는 보행 위상 추정 기술이 필수적으로 요구된다. 본 논문에서는 착용자의 보행 속도 변화 및 착용자 간 보행 특성 차이에도 강인하게 보행 위상을 추정할 수 있는 LSTM 기반 보행 위상 강건 인식 기술을 개발하였다. 웨어러블 고관절 보조 로봇을 착용한 총 5명의 트레드밀 및 실외 overground의 보행 센서 정보를 바탕으로 학습을 수행하였다. 저속 및 고속 보행을 포함한 다양한 보행 속도에서 정밀한 보행 위상 추정이 가능한 웨어러블 센서 조합을 도출하였고, 보행 위상 인식 정밀성은 5-Fold Cross Validation 기준 RMSE 약 1.68% 수준의 결과를 얻을 수 있었다.

• The Journal of Korean Physical Therapy
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• 제21권1호
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• pp.35-40
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• 2009

Purpose: The purpose of this study was to investigate change of muscle activities during level walking, stairs and ramp climbing in old adults. Methods: Twelve old adults were recruited and agreed this study. Muscle activity was measured by MP150 system (BIOPAC System Inc., Santa Barbara, USA). Statistical analysis was used one-way ANOVA to know the difference according to gait conditions (level walking, stairs and ramp ascending) Results: In stance phase, muscle activities of low extremities with old adults were generally significant difference in ramp ascending. In swing phase, rectus femoris and biceps femoris activity in old adults generally more increased during stairs ascending and tibialis anterior and gastrocnemius activity in old adults generally increased during ramp ascending. Conclusion: These results indicate that stair and ramp climbing is different muscle recruit pattern to level walking.

• 로봇학회논문지
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• 제13권2호
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• pp.97-102
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• 2018

A small and lightweight crawling robots have been actively studied thanks to their outstanding mobility and maneuverability. Those robots can navigate into more confined spaces that larger robots are unable to reach or enter such as debris and caves. In this paper, we propose a milli-scale hexapedal robot based on planar linkage design. To make this possible, two necessary conditions for successful crawling are satisfied: thrust force from the ground and aerial phase while running. These conditions are achieved through a newly developed leg design. The robot has a pair of legs and each leg has three feet. Those feet alternatively moves based on 1DOF planar linkage. This linkage is installed at each side of the robot and finally the robot shows the alternating gait and aerial phase during running. As a result, the robot runs with the crawling speed of 0.9 m/s.

• 대한의용생체공학회:의공학회지
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• 제22권1호
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• pp.29-34
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• 2001

본 연구의 목적은 대퇴부가 절단된 다리의 생체 역학적 기능을 복구할 수 있게 하는 의지의 개발을 위하여 5축 링크, 슬관절 완충장치를 사용하여 보행시 입각기를 제어할 수 있는 대퇴 의지 시스템 개발에 있다. 이를 위하여 입각기시 대퇴의지와 지면간 접촉 중 충격 에너지 흡수를 하는 슬관절 완충장치의 기계적 특성 및 거동을 분석하였다. 임상시험을 통하여 개발된 대퇴의지의 성능을 검증한 결과 대퇴 절단 피검자들의 보행특성은 정상인의 보행에 근접한 경향을 보였다. 결론적으로 본 연구에서 개발된 입각기 대퇴의지는 입각기시 현저한 보행 안전성을 보였다.

• 한국운동역학회지
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• 제33권3호
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• pp.94-100
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• 2023

Objective: Few studies have investigated alterations of ground reaction force (GRF) in individuals with chronic ankle instability (CAI) compared with lateral ankle sprain (LAS) copers and healthy controls during walking. This study aimed to investigate differences in GRF variables among the CAI, LAS coper, and control groups. Method: Eighteen individuals with CAI, 18 LAS copers, and 18 healthy controls were recruited for this study. All participants walked on 8-m walkway with a force plate three times. GRF data during stance phase were extracted and analyzed. The analysis of variance and ensemble curve analysis were used for statistical analyses of discrete points and time-series data respectively. Results: The CAI group showed a greater loading rate (LR) and a shorter time to impact peak force than the other groups, as well as decreased vGRF from 56% to 65% in the stance phase than the control group. No significant differences were noted in the other variables. Conclusion: Based on these findings, individuals with CAI should enhance their ability to create propulsion during the push-off phase and spend more time absorbing GRF to decrease the LR, which is considered one of risk factors for overuse injury and ankle osteoarthritis.

• Journal of Trauma and Injury
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• 제36권3호
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• pp.298-303
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• 2023

Unstable pelvic ring injuries are potentially life-threatening and associated with high mortality and complication rates in polytrauma patients. The most common cause of death in patients with pelvic ring injuries is massive bleeding. With resuscitation, external fixation can be performed as a temporary stabilization procedure for hemostasis in unstable pelvic fractures. Internal fixation following temporary external fixation of the pelvic ring yields superior and more reliable stabilization. However, a time-consuming extended approach to open reduction and internal fixation of the pelvic ring is frequently precluded by an unacceptable physiologic condition and/or concomitant injuries in patients with multiple injuries. Conservative treatment may lead to pelvic ring deformity, which is associated with various functional disabilities such as limb length discrepancy, gait disturbance, and sitting intolerance. Therefore, if the patient is not expected to be suitable for additional surgery due to a poor expected physiologic condition, definitive external fixation in combination with various percutaneous screw fixations to restore the pelvic ring should be considered in the acute phase. Herein, we report a case of unstable pelvic ring injury successfully treated with definitive external fixation and percutaneous screw fixation in the acute phase in a severely injured polytrauma patient.