• Title/Summary/Keyword: Elastic joint

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Immediate Effect of Anterior-to-posterior Talocrural Joint Mobilization with Elastic Taping on Balance Ability in Stroke Patients

  • Park, Shin-Jun;Kim, Soon-Hee
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.3
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    • pp.91-97
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    • 2018
  • PURPOSE: Stroke patients have reduced balance ability due to a lack of motion in the ankle joint. Elastic taping assists movement, and joint mobilization, a form of passive movement, enhances mobility. The purpose of this study was to determine the immediate effects on balance ability after anterior-to-posterior (A-P) talocrural joint mobilization combined with elastic taping in stroke patients. METHODS: Twenty stroke patients were divided into two groups: a joint mobilization with taping group (experimental group, n=10) and an elastic taping only group (control group, n=10). The experimental group underwent anteroposterior mobilization of the talus and elastic tape was applied to the calf and tibialis anterior muscles. The control group had elastic tape applied. Dynamic balanced abilities were assessed by using the BioRescue system. After 30 minutes of intervention, the forward, backward, left side, and right side sway areas ($mm^2$) were measured. RESULTS: Only the experimental group showed a significant increase in forward sway area after intervention. However, no significant differences were detected between the two groups. CONCLUSION: This study shows that A-P talocrural joint mobilization combined with elastic taping has a positive effect, producing an immediate increase in the forward balance ability of stroke patients. However, this study did not examine joint mobilization alone. In subsequent studies, it is necessary to examine the effect of joint mobilization only on balance in stroke patients.

Estimation of Elastic Modulus in Rock Mass for Assessing Displacment in Rock Tunnel (암반터널에서의 변위파악을 위한 암반 탄성계수 추정)

  • Son, Moorak;Li, Sudan;Lee, Wonki
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2C
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    • pp.83-92
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    • 2011
  • Elastic modulus in rockmass is an important factor to represent the characteristic of rock deformation and is used to estimate the displacement due to tunnel excavation. Nevertheless, the study to estimate the elastic modulus, which condisiders the rock type and joint characteristics (joint shear strength and joint inclination angle), has been done in less frequency. Accordingly, this study is aimed at providing the method to estimate the elastic modulus of rockmass in the various rock and joint conditons and the results grasped from the study. For this purpose, the 2D discrete numerical analysis will be carried out and the displacements due to tunnel excavation will be investigated with the consideration of rock and joint conditions. Then the displacement results will be used to estimate the elastic modulus of rockmass in which rock and joint conditions are considered with the utilization of the elastic theory of circular tunnel. The results of elastic modulus, which considers the conditions of various rock and joint, would be expected to have a great practical use in field.

An Elastic Joint Manipulator for a Human friendly robot

  • Takahashi, Takayuki;Murayama, Yasushi;Wang, Zhi-Dong;Nakano, Eiji
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.44.3-44
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    • 2001
  • This articles describes a novel design elastic joint manipulator for a mobile robot, which works in an office environment with humans. The primary goal of this manipulator design is safeness on collision and contact. To achieve this, each joint is made of an elastic element and this is driver with a high ratio gear tram. The performance was verified, however, it has a serious drawback. It produce vibration, due to the elastic joints and high ratio gear train. We found that a sliding mode controller has an excellent performance for reducing such vibration. Results of computer simulation and experiments are shown.

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Seismic detailing of reinforced concrete beam-column connections

  • Kim, Jang Hoon;Mander, John B.
    • Structural Engineering and Mechanics
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    • v.10 no.6
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    • pp.589-601
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    • 2000
  • A simplified analysis procedure utilizing the strut-tie modeling technique is developed to take a close look into the post-elastic deformation capacity of beam-column connections in ductile reinforced concrete frame structures. Particular emphasis is given to the effect of concrete strength decay and quantity and arrangement of joint shear steel. For this a fan-shaped crack pattern is postulated through the joints. A series of hypothetical rigid nodes are assumed through which struts, ties and boundaries are connected to each other. The equilibrium consideration enables all forces in struts, ties and boundaries to be related through the nodes. The boundary condition surrounding the joints is obtained by the mechanism analysis of the frame structures. In order to avoid a complexity from the indeterminacy of the truss model, it is assumed that all shear steel yielded. It is noted from the previous research that the capacity of struts is limited by the principal tensile strain of the joint panel for which the strain of the transverse diagonal is taken. The post-yield deformation of joint steel is taken to be the only source of the joint shear deformation beyond the elastic range. Both deformations are related by the energy consideration. The analysis is then performed by iteration for a given shear strain. The analysis results indicate that concentrating most of the joint steel near the center of the joint along with higher strength concrete may enhance the post-elastic joint performance.

Effect of the Non-Elastic Taping Method of Controlling Internal Hip Joint Rotation on Hip Muscle Activity: A Preliminary Study (엉덩관절 안쪽돌림 조절을 위한 비탄력 테이핑 방법이 엉덩관절 근활성도에 미치는 영향 -예비연구-)

  • Song-Ui Bae;Ju-Hyeon Jung;Dong-Chul Moon
    • PNF and Movement
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    • v.21 no.3
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    • pp.281-289
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    • 2023
  • Purpose: This study investigated the effects of the non-elastic taping method for controlling internal hip joint rotation on internal and external hip rotator muscle activity in healthy people. Methods: In this study, 18 healthy volunteers were instructed to perform the small knee bending (SKB) test. All participants completed the test following two methods (using non-elastic taping and not using taping). Muscle activation during the two methods was measured using a surface electromyography (EMG) device. Surface EMG data were collected from the gluteus medius, gluteus maximus, and tensor fasciae femoris muscles while performing the SKB test with and without non-elastic taping. Results: Muscle activity in the gluteus maximus was significantly higher during the SKB test with non-elastic taping than during the conventional SKB test with taping (p < 0.05). Tensor fasciae latae muscle activity was lower during the SKB test with non-elastic taping than during the conventional SKB test (p < 0.05). Conclusion: The findings suggest that the non-elastic taping method for controlling internal hip joint rotation effectively activates the hip's external rotator muscles and minimizes unwanted internal rotator muscle use during the SKB test. Therefore, the non-elastic taping method for controlling internal hip joint rotation could be an effective intervention for those who cannot control the internal rotation of their hips.

Study on Numerical Analysis of Estimating Elastic Modulus in Rockmass with a Consideration of Rock and Joint Characteristcs (암석 및 절리특성을 고려한 암반의 탄성계수 추정에 관한 수치해석적 연구)

  • Son, Moorak;Lee, Wonki
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.1
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    • pp.229-239
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    • 2013
  • Elastic modulus in rockmass is an important factor to represent the characteristic of rock deformation and is frequently used to estimate the displacement induced due to tunnel excavation or other activities in rockmass. Nevertheless, the study to estimate the elastic modulus, which considers the rock type and joint characteristics (joint shear strength and joint inclination angle), has been done in less frequency. Accordingly, this study is aimed at estimating of elastic modulus in jointed rockmass. For this purpose, numerical parametric studies have been carried out with a consideration of rock and joint conditions. Tunnel displacement results have been used to estimate the elastic modulus of jointed rockmass using the elastic theory of circular tunnel. From this study, the results would be expected to have a great practical use for estimating the displacement induced due to tunnel excavation or other activities in jointed rockmass.

Comparison of the Effects of Non-elastic Taping on Patellar tendon Pain, Knee Muscle Strength and Gait in Patients with Patellofemoral Joint Pain Syndrome (비탄력 테이핑이 슬개대퇴관절 통증증후군 환자의 슬개건 통증과 슬관절부 근력, 보행에 미치는 영향 비교)

  • Jung, Sang-mo;Jung, Young-jun;Ahn, Seung-won
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.25 no.2
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    • pp.39-46
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    • 2019
  • Background: Ground repulsion or impact on the ground during daily activities, sports, or occupational activities may cause injury to the knee when walking. Non-elastic taping is effective in treating these problems in previous studies. Non-elastic taping strengthens the structure of the soft tissues of the injured knee joint to maintain constant tension, improves muscle rearrangement and function, and improves proprioception. Based on previous studies, we intended to see the therapeutic changes of non-elastic taping in patients with patellofemoral joint pain syndrome. Methods: The non-elastic taping application method was applied to the patient three times for five hours for one week. Non-elastic taping was applied to the patellar tendon with little space above the skin segment of the patellar femur, with both sides fixed by taping. Muscle strength and gait change were evaluated with non-elastc taping. Results: The knee flexion, extension strength and gait evaluation of the knee joint with inelastic taping showed significant differences after treatment. There was a significant difference in the comparison between the two groups after the treatment method was applied (p<.05). Conclusion: As a result, this study confirms that the non-elastic taping method applied for the treatment of patellar femoral joint pain syndrome is effective in the treatment.

Estimation of Elastic Modulus of Jointed Rock Mass under Tunnel Excavation Loading (터널 굴착하중 조건에서의 절리암반의 탄성계수 예측)

  • Son, Moorak;Lee, Won-Ki;Hwang, Young-Cheol
    • Journal of the Korean Geotechnical Society
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    • v.30 no.7
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    • pp.17-26
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    • 2014
  • Tunneling-induced displacement in a jointed rock mass is an important factor to control tunnel stability and to secure a demanded space and construction quality. The magnitude of the inducible displacements is significantly affected by an elastic modulus and therefore, in a rock mass where a joint controls tunnel behavior, it is very important to estimate an elastic modulus of jointed rock mass reliably. Elastic modulus of jointed rock mass is affected by many factors such as rock type, joint condition, and loading condition. Nevertheless, most existing studies were focused on rough empirical relationships based on compressive loading conditions, which are different from tunnel excavation loading conditions, without a systematic approach of rock, joint, and loading conditions together. Therefore, this study considered rock and joint conditions systematically to estimate an elastic modulus of jointed rock mass under tunnel excavation loading. The controlled factors considered in this study are rock types and joint conditions (joint shear strength, joint inclination angle, number of joint sets, and joint spacing). Numerical parametric studies have been carried out with a consideration of different rock and joint conditions; the results have been compared with existing empirical relationships; and charts of elastic modulus change of different rock and joint conditions have been provided. The results are expected to have a great practical use for estimating the convergence induced by tunnel excavation in jointed rockmass.

Preliminary numerical study on long-wavelength wave propagation in a jointed rock mass

  • Chong, Song-Hun;Kim, Ji-Won;Cho, Gye-Chun;Song, Ki-Il
    • Geomechanics and Engineering
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    • v.21 no.3
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    • pp.227-236
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    • 2020
  • Non-destructive exploration using elastic waves has been widely used to characterize rock mass properties. Wave propagation in jointed rock masses is significantly governed by the characteristics and orientation of discontinuities. The relationship between spatial heterogeneity (i.e., joint spacing) and wavelength for elastic waves propagating through jointed rock masses have been investigated previously. Discontinuous rock masses can be considered as an equivalent continuum material when the wavelength of the propagating elastic wave exceeds the spatial heterogeneity. However, it is unclear how stress-dependent long-wavelength elastic waves propagate through a repetitive rock-joint system with multiple joints. A preliminary numerical simulation was performed in in this study to investigate long-wavelength elastic wave propagation in regularly jointed rock masses using the three-dimensional distinct element code program. First, experimental studies using the quasi-static resonant column (QSRC) testing device are performed on regularly jointed disc column specimens for three different materials (acetal, aluminum, and gneiss). The P- and S-wave velocities of the specimens are obtained under various normal stress levels. The normal and shear joint stiffness are calculated from the experimental results using an equivalent continuum model and used as input parameters for numerical analysis. The spatial and temporal sizes are carefully selected to guarantee a stable numerical simulation. Based on the calibrated jointed rock model, the numerical and experimental results are compared.

Residual Stress Analysis in Bi-material Metal Joint under Bending Moment by Finite Element Method (이종재료 금속조인트의 굽힘에 의한 잔류응력 해석)

  • Baek Tae-Hyun;Jung Girl;Park Tae-Geun
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.448-451
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    • 2005
  • It was observed that after unloading or removal of the load from the specimen subjected to bending stress, partial or full elastic spring back occurred and considerable stresses have resulted while plastic deformation was considered. ABAQUS is a suite of powerful engineering simulation programs, based on the finite element method. In this paper, it was used as the main tool to analyze elastic and plastic deformations of hi-material metal joint. In the case of elastic deformations, the results were comparable to the theoretical data. Plastic deformations and residual stresses of hi-material metal joint under bending moment were obtained by ABAQUS; where the theory needs to be studied and improved further to verify the results.

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