• Title/Summary/Keyword: finger-joint

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Development of Flexible and Lightweight Robotic Hand with Tensegrity-Based Joint Structure for Functional Prosthesis (기능형 의수를 위한 텐스그리티 관절 구조 기반의 유연하고 가벼운 로봇 핸드 개발)

  • Geon Lee;Youngjin Choi
    • The Journal of Korea Robotics Society
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    • v.19 no.1
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    • pp.1-7
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    • 2024
  • This paper presents an under-actuated robotic hand inspired by the ligamentous structure of the human hand for a prosthetic application. The joint mechanisms are based on the concept of a tensegrity structure formed by elastic strings. These rigid bodies and elastic strings in the mechanism emulate the phalanx bones and primary ligaments found in human finger joints. As a result, the proposed hand inherently possesses compliant characteristics, ensuring robust adaptability during grasping and when interacting with physical environments. For the practical implementation of the tensegrity-based joint mechanism, we detail the installation of the strings and the routing of the driving tendon, which are related to extension and flexion, respectively. Additionally, we have designed the palm structure of the proposed hand to facilitate opposition and tripod grips between the fingers and thumb, taking into account the transverse arch of the human palm. In conclusion, we tested a prototype of the proposed hand to evaluate its motion and grasping capabilities.

A STUDY ON THE LAXITY OF THE TEMPOROMANDIBULAR JOINTS (악관절(顎關節)의 이완성(弛緩性)(LAXITY)에 관(關)한 연구(硏究))

  • Yoon, Chang-Keun;Ma, Jang-Seon
    • The Journal of Korean Academy of Prosthodontics
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    • v.20 no.1
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    • pp.51-66
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    • 1982
  • The purpose of this study was primarily to determine the relationship between temporomandibular joint mobility and generalized benign joint hypermobility. The subjects were 85 men and 76 women, who were students of dental and dental hygiene schools, aged 18 to 30 years old. They had no disturbances or complaints of movement of temporomandibular joints and other joints in the body. The joint mobility was measured by a test which is a modification of a method developed originally by Carter and Wilkinson (1964). The mandibular mobility was measured during active and passive maximal opening, laterotrusion, protrusion, and retrusion by Ingervall's method (1970). The obtained results were as follows: 1. The distribution of joint hypermobility disclosed was 4.8% in men and 19.7% in women, and 11.8% of total subjects. 2. The joint mobility index was a mean of 0.37 for men and 0.51 for women in total subjects, and 0.80 for men and 0.73 for women in hypermobile subjects. 3. The angle of passive dorsiflexion of the little finger was greater in the left than in the right hand for both sexes and in hypermobile subjects than in total subjects. 4. There was a positive correlation between the joint mobility index and the angle of passive dorsiflexion of the little finger in total subjects. 5. The joint mobility was greater in women than in men, and in the left than in the right hand. 6. In the active maximal mandibular movements of total subjects, the mean values for the opening capacity was 56.01 mm and 52.04mm, the laterotrusion mean 8.07 and 8.08, the protrusion mean 8.72 and 8.24, and the retrusion mean 0.48 and 0.49 for men and women respectively. 7. In the passive maximal mandibular movements of total subjects, the mean values for the opening capacity was 59.07mm and 54.85mm, the laterotrusion mean 8.90 and 9.12, the protrusion mean 10.03 and 10.00, and the retrusion mean 0.69 and 0.72 in men and women respectively. The active and passive maximal opening capacity was larger in men than in women but in the other movements there were no significant differences between men and women. 8. The range of active and passive maximal mandibular movements of hypermobile subjects tended to be larger in men but no significant difference in women compared with that of total subjects. 9. The range of maximal mandibular movements was increased more in passive than in active.

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Evaluation on Flexural Performance of Steel Plate Reinforced GLT Beams (강판 보강 집성재 보의 휨성능 평가 연구)

  • Park, Keum-Sung;Lee, Sang-Sup;Kwak, Myong-Keun
    • Journal of Korean Association for Spatial Structures
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    • v.20 no.2
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    • pp.39-49
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    • 2020
  • In this study, we will develop a hybrid cross-sectional shape of steel inserted type glued-laminated timber that can improve the strength of structural glued-laminated timber and maximize the ductility by using steel plate with excellent tensile and deformation ability. A total of three specimens were fabricated and the flexural performance test was carried out to evaluate the structural performance of the steel inserted type glued-laminated timber. In order to compare the effect of steel inserted glued-laminated timber, one structural glued-laminated timber test specimen composed of pure wood was manufactured. In addition, in order to evaluate the adhesion performance of the steel inserted, one each of a screw joint test specimen and a polyurethane joint test specimen was prepared. As a result, all the specimens showed the initial crack in the finger joint near the force point. This has been shown to be a cause of crack diffusion and strength degradation. The use of finger joints in the maximum moment section is considered to affect the strength and ductility of the glued-laminated timber beam. Polyurethane-adhesive steel inserted glued-laminated timber showed fully-composite behavior with little horizontal separation between the steel plate and glued-laminated timber until the maximum load was reached. This method has been shown to exhibit sufficient retention bending performance.

Effects of Transducer Position in Ultrasonics Nondestructive Tests of Finger-Jointed Lumber (손가락결합부재에 대한 초음파 비파괴시험에서 센서 위치의 영향)

  • Jang, Sang-Sik
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.1
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    • pp.1-6
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    • 1998
  • 손가락결합부재에 대한 정적휨시험 및 초음파 비파괴시험을 실시하였다. 발신 및 수신 변환기의 상대 위치와 두 변환기 사이의 거리에 따른 음전달속도의 변화를 분석하였으며 정적 휨시험으로 부터 구한 MOE 및 MOR과 비교하였다. MOR과 음전달속도는 손가락의 경사가 증가할수록 감소하였다. MOR은 음전달속도와 매우 밀접한 상관관계를 보였으나 MOE는 손가락의 경사도나 음전달속도에 큰 영향을 받지 않는 것으로 나타났다. 음전달속도는 섬유방향이 방사방향이나 접선방향에 비하여 더 높은 값을 나타내었다. 발신 및 수선 변환기를 동일면에 부착한 경우에 직각면 또는 반대면에 부착한 경우보다 더 높은 음전달속도를 나타내었다. 변환기 사이의 거리가 증가할수록 음전달속도는 양끝면에 변환기를 부착한 경우의 속도에 수렴하는 경향을 나타내었다.

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Damping Capacity of Finger-Jointed Lumber (손가락 결합부재의 감쇠거동)

  • Jang, Sang-Sik;Kang, Ho-Yang;Lee, Hwa-Hyoung
    • Journal of the Korean Wood Science and Technology
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    • v.22 no.4
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    • pp.43-50
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    • 1994
  • 본 연구는 침엽수재를 사용한 손가락결합부재의 강도 및 감쇠특성을 측정함으로서 문창틀재로의 사용가능성을 시험하기 위하여 수행하였다. 손가락결합부 시험편의 형태는 손가락부분의 길이와 경사도에 따라서 다섯가지로 제작하였다. 하중은 4개의 하중단계를 갖는 양방향휨으로 가하였으며 각각의 하중단계는 3개의 하중주기로 구성되었다. 손가락결합부의 파괴특성을 분석하기 위하여 감쇠시험 과정에 AE신호를 측정하였다. MOE는 시험편의 형태와 뚜렷한 관련을 갖고 있지 않으나, MOR은 손가락부분의 경사도가 증가될수록 감소되는 뚜렷한 관계를 나타내었다. 감쇠비는 하중단계가 증가될수록 감소되었으나 파괴직전의 단계에서는 증가되는 경향을 나타내었다. 하중방향에 대하여 수직한 방향의 손가락결합부재가 수평방향부재보다 더 높은 강도를 나타내었다. 60dB 이상의 AE신호는 목재 또는 접착층의 파괴에 의하여 발생되는 것으로 분석되었다. 완전한 파괴가 발생하는 경우에는 100dB 이상의 AE신호가 발생하였다.

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Cubital tunnel syndrome associated with previous ganglion cyst excision in the elbow: a case report

  • Woojin Shin;Taebyeong Kang;Jeongwoon Han
    • Clinics in Shoulder and Elbow
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    • v.27 no.1
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    • pp.131-135
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    • 2024
  • Cubital tunnel syndrome refers to compression neuropathy caused by pressure on the ulnar nerve pathway around the elbow. A 63-year-old male patient visited the clinic complaining of decreased sensation and weakness in his left ring finger and little finger, stating that the symptoms first began 6 months prior. He had undergone surgery to remove a ganglion cyst from his left elbow joint about 5 years prior in Mongolia. Magnetic resonance imaging revealed a cystic mass located at the previous surgical site, which was compressing the ulnar nerve within the cubital tunnel. Ulnar nerve decompression and anterior transposition were performed, and the cystic mass was excised. Upon pathological examination, the mass was diagnosed as a ganglion cyst. The patient's symptoms including sensory dysfunction and weakness improved over the 1-year follow-up period. This report describes a rare case of ganglion cyst recurrence compressing the ulnar nerve in the cubital tunnel after previous ganglion cyst excision.

The Bending Strength Properties and Acoustic Emissions to Sloped Finger-Jointed Pinus densiflora S. et Z. (소나무 경사핑거접합재의 휨강도성능과 AE 특성)

  • Byeon, Hee-Seop;Ahn, Sam-Keun;Kim, Jong-Man
    • Journal of the Korean Wood Science and Technology
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    • v.27 no.1
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    • pp.30-36
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    • 1999
  • This paper describes the relationship between the bending strength properties of sloped finger-jointed woods and the acoustic emissions (AEs) generated during the test. Pinus densiflora pieces were cut in sloped-finger types and glued with four kinds of adhesives (polyvinyl acetate, polyvinyl-aeryl, oilic urethane and resorcinol-phenol resin). The results were as follows: The lower the bending strength(load) was, the earlier the generation time of AE event count got and the higher the increasing rate of AE event count became in the sloped finger-jointed specimens bonded with polyvinyl acetate and oilic urethane resin adhesives. Therefore, the slope from load-AE cumulative event count curve was very steep. The AE event count for resorcinol-phenol resin adhesive obtained even from low load level was abundant. The AE event count continuously increased as load increased and the event count was much more than one in the other conditions. The slope from load-AE cumulative event count curve was very gentle compared with other conditions. The patterns of AE event count and count were very similar. The relationship between the MOR and the AE parameter from load and AE cumulative event count in the early stage of the sloped finger-jointed specimens bonded with polyvinyl acetate, oilic urethane and resorcinol-phenol resin adhesives was much greater than that between the MOE and the MOR. Therefore, the AE signals obtained during bending test are useful for estimating the strength of sloped finger-jointed specimens.

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The Effects of Joint Mobilization and Therapeutic Exercise on Difference for Length of Lower Limbs (운동치료와 관절가동술이 하지길이 차이에 미치는 영향)

  • Jung, Yeon-Woo;Gong, Won-Tae;Kim, Byoung-Gon
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.13 no.2
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    • pp.55-68
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    • 2007
  • Object: to evaluate the effects of two different treatments-joint mobilization and therapeutic exercise on difference for length of lower limbs. Method: The subjects were participated twenty six who has difference for length of lower limbs more 10mm. All subjects randomly assigned to Joint mobilization group(n=13) and therapeutic exercise group. Joint mobilization group received joint mobilization for 2 minutes, Therapeutic exercise group received for 15 minutes per day and 3 times a week during 4 week period. Tape measure method was used to measure the difference for length of lower limbs. Biodex was used to measure the muscle power of lower limbs(Knee flexion, extension). Finger to floor test was used to measure the mobility of spinal column. All measurement of each subjects were measured at pre-experiment, after 2weeks and post-experiment. Result: The result of this study were summarized as follows : 1. Both treatment decreased difference for length of lower limbs while joint mobilization more decreased difference for length of lower limbs than therapeutic exercise. 2. Both treatment increased mobility of spinal column while joint mobilization more increased mobility of spinal column than therapeutic exercise. 3. Joint mobilization increased muscle power while therapeutic exercise decreased muscle power. Conclusion: in a group-wise comparison joint mobilization is more effective than therapeutic exercise.

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Reliability Study of Three-Dimensional Motion Analysis Program for Wrist and Finger Joint Range of Motion Measurement (손목 · 손가락 관절가동범위 측정에 관한 3차원 동작분석 프로그램의 신뢰도 연구)

  • Park, Sun Ha;Park, Ji-Hyuk;Kim, Jong Bae;Jung, Young Jin;Lee, Joo Hyun;Park, Hae Yean
    • Therapeutic Science for Rehabilitation
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    • v.12 no.1
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    • pp.79-92
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    • 2023
  • Objective : This study aimed to assess the reliability of a three-dimensional (3D) motion analysis program for measuring the range of motion (ROM) of wrist and finger joints. Methods : The study recruited 50 people who had no restrictions on wrist and finger movements, understood the purpose of this study, and agreed to participate. Using a goniometer and a 3D motion analysis program, a total of 11 wrist and finger ROM were measured once each. To measure the reliability of the 3D motion analysis program, the degree of agreement and inconsistency of the measured values were compared. Results : Analysis of the degree of agreement of the measured values revealed that 38 out of 44 items showed a very high degree of agreement. Regarding analysis of inconsistency in the measured values, inconsistencies were found in three items. Conclusion : The results of this study confirmed that the ROM of the joint could be measured using the 3D motion analysis program applied in this study. In addition, it might be expected that the 3D motion analysis program would be used in various clinical fields owing to the advantages of measurement convenience and accuracy.

Study of the correlation between postpartum joint symptoms and maternity season within 15 days after giving birth (출산 후 15일 이내에 나타난 관절증상과 출산계절의 상관성 연구)

  • Koo, Jin Suk;Kim, Yun Young;Seo, Bu Il
    • The Journal of Korean Medicine
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    • v.38 no.1
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    • pp.125-133
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    • 2017
  • Objectives: The purpose of this study is to investigate the correlation between postpartium joint diseases and maternal season. So it can prevent postpartum joint diseases and provide fundamental data about postpartum health care. Methods: The subject of the present study was 219 women (142 women who completed vaginal delivery and 77 women who delivered by cesarean section) who completed labor between November 1, 2013 and November 31, 2016, at the clinic of OB&GYN. They have been taking good care of their health at postpartum clinic in Andong Woori Women Hospital. We investigated the various symptoms and situation which occurred from the moment of hospital to postnatal admission health care period and oriental doctor examined the patients. We classified the symptoms by the age of patients, the method of delivery, the term of pregnancy, the body weight of infant, the weight change of mother and the way of feeding. Through data analysis, we investigated the correlation between maternal season and postpartum joint diseases. Results: Postpartum joint diseases were the most common among all symptoms after childbirth. Postpartum joint diseases were classified into shoulder area pain and low back pain. In low back pain, there was no significant difference between maternal season and postpartum joint diseases. In shoulder, wrist and finger pain, pain was the most severe at winter delivery. It was the most painful in winter, followed by autumn, spring and summer. Conclusion: There was a close correlation between postpartum joint disease manifestations and maternal season.