• Title/Summary/Keyword: Brace

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Experimental and numerical study of a proposed steel brace with a localized fuse

  • Parsa, Elham;Ghazi, Mohammad;Farahbod, Farhang
    • Structural Engineering and Mechanics
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    • v.84 no.2
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    • pp.269-283
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    • 2022
  • In this paper, a particular type of all-steel HSS brace members with a locally reduced cross-sectional area was experimentally and numerically investigated. The brace member was strengthened against local buckling with inner and outer boxes in the reduced area. Four single-span braced frames were tested under cyclic lateral loadings. Specimens included a simple steel frame with a conventional box-shaped brace and three other all-steel reduced section buckling-restrained braces. After conducting the experimental program, numerical models of the proposed brace were developed and verified with experimental results. Then the length of the proposed fuse was increased and its effect on the cyclic behavior of the brace was investigated numerically. Eventually, the brace was detailed with a fuse-to-brace length of 30%, as well as the cross-sectional area of the fuse-to-brace of 30%, and the cyclic behavior of the system was studied numerically. The study showed that the proposed brace is stable up to a 2% drift ratio, and the plastic cumulative deformation requirement of AISC (2016) is easily achieved. The proposed brace has sufficient ductility and stability and is lighter, as well as easier to be fabricated, compared to the conventional mortar-filled BRB and all-steel BRB.

Review of Flexible brace(SpineCor Brace) in Pubmed, CNKI and Journal of Korean Oriental Medicine ; RCTs(Randomized controlled trials) Review (스파인코 보조기의 척추 측만증에 대한 효과 고찰)

  • Kim, Seong-Tae;Na, Eun-Ji;Gwon, Min-Goo;Hwang, Chun-Ho;Kim, Min-Seong;Park, Jin-Woo;Sung, In-Hyung k.;Jo, Hee-Geun;Sul, Jae-Uk
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.10 no.1
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    • pp.35-45
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    • 2015
  • Objectives : To evaluate the clinical effectiveness of Flexible brace(SpineCor Brace). Methods : CNKI, PubMed databases and Korean Journal of Oriental Medicine in 1999-2014 were searched for studies on SpineCor. This study researched 4 randomized controlled trial studies. Results : The results suggested that the SpineCor brace reduced the probability of the progression of early idiopathic scoliosis comparing with its natural history or rigid brace. But some studies showed that there is no significant difference between SpineCor and rigid brace. Conclusions : These results indicate that SpineCor have obvious effects on treatment of scoliosis and no adverse reactions, therefore we need to study more researches on SpineCor.

Mechanics of a variable damping self-centering brace: Seismic performance and failure modes

  • Xie, Xing-Si;Xu, Long-He;Li, Zhong-Xian
    • Steel and Composite Structures
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    • v.31 no.2
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    • pp.149-158
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    • 2019
  • The force-deformation behavior, strain distribution and failure modes of a variable damping self-centering brace (VD-SCB) are theoretically analyzed, experimentally studied, and numerically simulated to guide its design. The working principle of the brace is explained by describing the working stages and the key feature points of the hysteretic curve. A large-scale brace specimen was tested under different sinusoidal excitations to analyze the recentering capability and energy dissipation. Results demonstrate that the VD-SCB exhibits a full quasi-flag-shaped hysteretic response, high ultimate bearing capacity, low activation force and residual deformation, and excellent recentering and energy dissipation capabilities. Calculation equations of the strain distribution in different parts of the brace are proposed and are compared with the experimental data and simulated results. The developments of two failure modes are compared. Under normal circumstances, the brace fails due to the yielding of the spring blocking plates, which are easily replaced to restore the normal operating conditions of the brace. A brief description of the design procedure of the brace is proposed for application.

A Study on EMS Protective Gear Design and Its Effects for Elite Badminton Players with Knee Pain (무릎 통증이 있는 엘리트 배드민턴 선수를 위한 건식 E-textile 전극의 EMS(Electirc muscle stimulation) 보호대 설계 및 효과)

  • JuIl Lee;Jinhee Park;Jooyong Kim
    • Journal of Fashion Business
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    • v.27 no.5
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    • pp.93-107
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    • 2023
  • This study aimed to design a knee brace with dry electrode EMS (Electrical Muscle Stimulation) for elite badminton players suffering from knee pain and assess its effectiveness in relieving pain and improving mobility. The assessment measured knee joint range of motion (ROM), Sargent jump height, and pain perception using a visual analog scale (VAS). Four experimental groups were established: stability, pain induction after 100 squats, muscle soreness induction with a regular knee brace, and muscle soreness induction with the EMS knee brace. The most suitable knee brace was selected from four samples to design the EMS knee brace. The conductive fabric was integrated into the inner surface of the knee brace to enhance EMS conductivity for the quadriceps muscles. Tensile strength tests showed that the dry electrode did not significantly affect the physical functionality of the knee brace.Regarding knee joint ROM and Sargent jump height, the EMS knee brace outperformed muscle soreness induction with a regular knee brace and wearing a standard knee brace. VAS measurements demonstrated that the EMS braces effectively alleviated pain perception in most cases. The results indicate the potential for developing EMS braces to alleviate pain and prevent injuries for athletes across various sports.

The Effects of Knee Brace on the Knee Muscular Neuro-Biomechanical Variables during the Rebound in Female Highschool Basketball Players (여자 고등학교 농구 선수들이 리바운드 점프 후 착지할 때 무릎보호대가 무릎의 근신경 생체역학적 변인에 미치는 효과)

  • Han, Ki-Hoon;Lim, Bee-Oh
    • Korean Journal of Applied Biomechanics
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    • v.17 no.4
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    • pp.107-113
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    • 2007
  • The purpose of this study were to investigate the effects of knee brace on the knee muscular neuro-biomechanical variables during the rebound in female highschool basketball players. Twelve high school female ($17.9{\pm}0.8years$) basketball players rebound jumped for maximal vertical height to sufficiently stress the anterior cruciate ligament with and without knee brace. Kinematic data were collected to estimate the knee flexion, abduction angles and jump height. The EMG data from the biceps femoris and rectus femoris was used to estimate the ratio of quadriceps muscle activity. Female athletes with knee brace showed more reduced the knee abduction angle and the ratio of quadriceps muscle activity at foot contact phase than without knee brace. In conclusion, Female athletes with brace reduced knee anterior cruciate ligament loads.

An Experimental Study on Fatigue Life of Brace Mounting Joint (브레이스 마운팅 결합부의 피로 수명에 관한 실험적 연구)

  • 김동우
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.3
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    • pp.104-109
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    • 1998
  • This document is a experimental study on fatigue life of brace mounting weld joint. A brace is used to put sub-frame together on the main frame with high strength bolts. It has low fatigue life so a patch is in need for improving a fatigue characteristics of welded joint in brace mounting This paper presents the most pertinent patch size for truck. For this, a critical stress is computed at the point of fatigue crack occurred on truck frame by finite Element Analysis. Using by this critical stress. Designers are able to determin whether fatigue crack is occurred and are able to select a pertinent patch type. And then, with a selected patch type, structural joint stiffness was estimated to compare to the conventional and other patch type or brace mounting Finally, fatigue test were performed to prove a suitability of selected prototype compare with the conventional and other patch type or brace mounting.

Effects of Knee Brace on the Anterior Cruciate Ligament Injury Risk Factors during Spike Take Off in Female Volleyball Players (여자 배구 선수들의 스파이크 도약 시 무릎보호대가 전방십자인대 부상위험 요인에 미치는 영향)

  • Yang, Chang-Soo;Lim, Bee-Oh
    • Korean Journal of Applied Biomechanics
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    • v.24 no.1
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    • pp.27-33
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    • 2014
  • In volleyball, the most common injuries are anterior cruciate ligament (ACL) tears. For this reason, volleyball players frequently use knee brace as prophylactic and rehabilitation measures. The purpose of the study was to investigate the effects of knee brace on anterior cruciate ligament injuries risk factors during spike take off in female volleyball players. Fifteen female volleyball players were recruited and performed randomly spike take off with and without knee brace. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. The ACL risk factors are knee maximum flexion angle, thigh maximum adduction angle, thigh maximum internal rotation angle, shank maximum abduction angle, shank maximum external rotation angle, knee maximum extension moment and knee maximum abduction moment. Data were analyzed with paired samples t-test with Bonfferoni collection. Female volleyball players with knee brace had no significant results in knee maximum flexion angle, thigh maximum adduction angle, thigh maximum internal rotation angle, shank maximum abduction angle and shank maximum external rotation angle compare to without knee brace. Female volleyball players, however, with knee brace showed more reduced knee maximum extension moment and knee maximal abduction moment than without knee brace. In conclusion, Female volleyball players with knee brace reduced anterior cruciate ligament stress.

The Development of a Wrist Brace using 3D Scanner and 3D Printer (3D 스캐너와 3D 프린터를 활용한 손목보호대 개발)

  • Koo, Da Som;Lee, Jeong Ran
    • Fashion & Textile Research Journal
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    • v.19 no.3
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    • pp.312-319
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    • 2017
  • The purpose of this study was to develop a customized wrist brace using 3D scanner and 3D printer. This study included in-depth interviews with people who had wrist pain and ever used wrist braces. The wrist brace has been designed and modeled by the CAD program after 3D scanning the wrist of subjects. Based on the results of the in-depth interviews on wrist brace users and design investigation in the market, a prototype of the wrist brace has been created. The wrist brace does not compress the hand and is easy to put on. In addition, it is adjustable to the wrist of users, allowing them to move his or her wrist without any restrictions. A computer-modeling program produced solid files for the design of the wrist brace after 3D scanning ten subjects' hands. It features a lattice-patterned surface, a velcro adjustment and trimming to smoothen the surface. PLA filaments were used to 3D print the wrist brace. As for the assessment, the wrist brace has been evaluated to be easy to put on and adjust to user's wrist. However, when it comes to appearance and comfortability, it was rated 3.0 or slightly above. This is because 3D printing materials are firm and not flexible compared to other materials such as neoprene or stretchable bands.

Changes in the Cervical and Lumber Flexion-Relaxation Ratio, Range of Motion, Pressure Pain Threshold, and Perceived Comfort Following the Wearing of a Trunk Brace during Smartphone Watching (스마트폰 시청 시 몸통 교정기 착용에 따른 목, 허리 굽힘-이완 비율, 관절가동범위, 압통, 착용감 변화)

  • Park, Jin-Seong;Park, Du-Jin
    • PNF and Movement
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    • v.19 no.3
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    • pp.413-422
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    • 2021
  • Purpose: This study was conducted to investigate changes in the cervical and lumbar flexion-relaxation ratio, range of motion, pressure pain threshold, and perceived comfort following the wearing of a trunk brace during smartphone watching. Methods: To calculate the number of subjects for this study, an analysis with G*Power was performed at a statistical power of 0.8, an effect size of 0.5, and a significance level of 0.05, based on the results of a preliminary experiment on five subjects. In total, 27 adult men and women were recruited who had been informed of the study's purpose and process and had agreed to participate. All subjects watched content on a smartphone for 20 minutes in the same posture and conditions while wearing and not wearing a trunk brace, and then their cervical and lumbar flexion-relaxation ratio, range of motion, pressure pain threshold, and perceived comfort were measured. Results: Compared to the non-wearing of a trunk brace, the wearing of a trunk brace resulted in a statistically significant smaller decline in cervical extension and right-side cervical rotation (p<0.05). When the subjects wore a trunk brace, their right- and left-side cervical and right-side lumbar pressure pain statistically significantly improved when compared to not wearing a trunk brace (p<0.05). They also perceived a significantly lowered level of comfort 20 minutes after wearing a trunk brace compared to immediately after wearing it (p<0.05). Conclusion: The trunk brace was effective in reducing declines in right-side cervical rotation and the occurrence of left- and right-side cervical and right-side lumbar pressure pain. The findings indicate the need to improve the perceived comfort of trunk braces.

Stiffened Effect of Knee Brace of Cross-Beam in Steel Box-girder Bridges (강박스거더교 가로보 니브레이스(Knee Brace)의 보강효과)

  • Gil, Heung Bae;Jang, Gab Chul;Kang, Sang Gyu;Lee, Il Keun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3A
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    • pp.227-234
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    • 2009
  • Recently, a knee brace is usually installed in connection between cross-beam and main-girder of steel box-girder bridges. The knee brace is installed as a structural stiffener and mainly aims to relieve stress at joints and to prevent main-girder from lateral deformation. However, research on the knee brace is insufficient to obviously evaluate the necessity. The stiffened effect of knee brace is determined by using finite element analyses. Stress distribution, stress level of members and deflection of the cross-beam are evaluated by parametric FE analysis for the installation of knee brace and the depth ratio of cross-beam/steel box girder. It is seen from comparison of numerical analysis results that the knee brace installed in cross-beam of steel boxgirders bridges is not efficient as a structural stiffener with respect to stress relief and stiffened effect.