• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.6
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• pp.738-743
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• 2007

In this paper, a muscle motion sensing system and an artificial arm control system are studied. The artificial arm is for the people who lost one's forearm. The muscle motion sensing system detect the intention of motion from the upper arm's muscle. In sensing system we use flex sensors which is electrical resistance type sensor. The sensor is attached on the biceps brachii muscle and coracobrachialis muscle of the upper arm. We propose an algorithm to classify the one's intention of motions from the sensor signal. Using this algorithm, we extract the 4 motions which are flexion and extension of the forearm, pronation and supination of the arm. To verify the validity of the proposed algorithms we made experiments with two d.o.f. artificial arm. To reduce the control errors of the artificial arm we also proposed a fuzzy PID control algorithm which based on the errors and error rate.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.265-266
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• 2011

본 연구에서는 유한요소 해석 방법을 이용하여 척추 퇴행성 질환을 가진 환자의 관절 불안정 모델을 개발 및 검증하였다. 관절 불안정 모델은 정상요추 유한요소 모델의 인대 및 협부를 결손시켜 개발하였으며, 요추 유한요소 모델의 제 5 요추체를 완전히 고정시키고 추적 경로 방향의 400 N의 압축력을 가한 상태에서 10 Nm의 굴곡과 신전 모멘트를 가하였다. 굽힘 및 신전 시 관절 불안정 모델들의 회전량이 정상의 요추 모델의 회전량에 비하여 크게 나타났다. 또한 굽힘 시 관절 불안정 모델들의 전위거리가 정상에 비하여 크게 나타났다. 본 연구의 결과는 척추 불안정성의 원인 및 기전의 이해뿐만 아니라 다양한 인체정보 콘텐츠 분야에 널리 활용될 수 있을 것으로 생각된다.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.151-159
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• 2008

In this research, kinematic comparative analysis was performed on strokes of abscission and spinal cord injured athletes who participated in 2008 Beijing Paralympics wheelchair table tennis games. Strokes of all situations were collected under real match-like conditions. Among those, three major forehand stroke motions and backhand stroke motions were drawn Data collected by 9 infrared cameras were expressed in angular motions using graphic program LabVIEW7.0. As a result, forehand stroke of spin handicap athlete from analyzed images, the rotations of the trunk happened with the rotations of shoulder and the flexion extensions of elbow nearly at the same time. According to these results, insufficient turning force or speed of rackets is recompensed using flexion. backhand stroke of spin handicap athlete from analyzed images, the rotations of the trunk, the flexion extensions of the elbow and the flexion extensions of the shoulder were lined up on the prolongations of ping-pong balls. Forehand stroke of abscission athletes was done by outward rotation of the arm using backswing and inner rotation. As for backhand stroke, backswing was made by inner rotation in the spin of shoulder and waist. And after the backswing, impact was formed in wide outer rotation towards the ball.

• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.479-486
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• 2015

This study was conducted to investigate the effects of upper thoracic joint mobilization technique using Kaltenborn-Evjenth concept on the range of cervical and thoracic motion and pain in patients with chronic neck pain. The subjects were divided into a thoracic joint mobilization group(n=7) and a conservative physical therapy group(n=7). Each of the groups received thoracic joint mobilization or conservative physical therapy three times a week lasted for four weeks. The measurements were performed for the range of thoracic segmental motion(SpinalMouse), the pain(visual analogue scale) and the range of cervical joint motion(Inclinometer, Dualer IQ). They were made four times: before experiment, at 2weeks, 4weeks, and 4weeks after experiment.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.99-105
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• 2007

Purpose: The morphological study and dynamic stability of the ulnar nerve around the elbow joint was investigated in asymptomatic normal population using ultrasonography. The purpose of this study is to provide fundamental data for ultrasonographic diagnosis of ulnar neuropathy in cubital tunnel syndrome. Materials and Methods: Fifty cases of 25 healthy male volunteers, aged between 20 to 30 years, included in this study. High resolution 7.5 MHz linear probe was used to examine the ulnar nerve in axial and longitudinal views. In a longitudinal view, the course, position and the thickness of nerve were monitored, the diameter of ulnar nerve and dynamic stability at elbow flexion and extension were measured in an axial view at four different points; 1cm proximal to medial epicondyle, behind the medial epicondyle, entrance to Osborne ligament, and 1cm distal to Osborne ligament. Results: The short diameters of ulnar nerve at elbow extension at four anatomic points were 2.66 mm, 2.97 mm, 2.64 mm, and 2.69 mm and the long diameters were 4.61 mm, 4.56 mm, 4.36 mm, and 4.37 mm, which showed no significant change at each point. However, at elbow flexion, the short diameters were changed to 2.72 mm, 2.34 mm, 2.65 mm, and 2.41 mm and the long diameters into 4.49 mm, 5.40 mm, 4.16 mm, and 4.66 mm. At elbow flexion, significant morphologic change was observed in the medial epicondyle area, and the diameter of the ulnar nerve was shortest at the entrance of Osborne ligament both at flexion and extension. In terms of dynamic stability, nine subluxations and seven dislocations were observed. Conclusion: This study shows dynamic instability and a morphological change of long and short diameters of ulnar nerve at flexion and extension in a normal person, which should be considered in the ultrasonographic diagnosis of ulnar neuropathy.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.267-268
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• 2011

본 연구에서는 유한요소 해석 방법을 이용하여 경추 유한요소 모델을 개발하고, 척추 인공디스크 수술 후 경추 분절의 생체역학적 특성을 평가하였다. 반구속 및 비구속 개념의 인공디스크가 삽입된 경추 유한요소 모델의 제 7 경추체를 완전히 고정시키고 추적 경로 방향의 50 N의 압축력을 가한 상태에서 1 Nm의 굴곡과 신전, 측면 굴곡, 비틀림 모멘트를 가하였다. 모든 방향의 하중 조건에서 인공디스크가 삽입된 경추 모델들의 회전량이 정상 경추 모델의 회전량에 비하여 크게 나타났다. 또한 인공디스크를 삽입한 운동 분절에서 정상에 비하여 후관절의 접촉력과 여섯 가지 주요 인대에 걸리는 응력이 높게 나타났다. 본 연구의 결과는 척추 인공디스크 수술 시 수술 방법의 선택뿐만 아니라 새로운 경추 수술용 임플란트 개발을 위한 인체정보 콘텐츠를 구축하는데 유용하게 활용될 수 있을 것으로 기대된다.

• Korean Journal of Applied Biomechanics
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• v.12 no.2
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• pp.131-142
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• 2002

The purpose of this study was to analyze kinematic variables of a Mae-ukemi (forward breakfall :MU) in Judo through 3-D image analysis with five Judoka with over 2 years' career (2nd dan, 3rd dan). The kinematic variables include posture, and distance variables; the mean values and the standard deviations for each variable were obtained to analyze kinematic variables of a MU in Judo. From the data analysis and discussion, the following conclusions were drawn : 1) Posture variables : The angles of wrists during right before Mae-ukemi (RBU) were extended from the just MU position(MUP) and flexed from in the right after MU(RAU), and there was a difference in the displacement between the angles of the right and left wrists. The angles of elbows were flexed in the ready position from in the RAU. The angles of ankles were flexed from the ready position to that down position, extended from the down position to that transition, and flexed from the transition positiont to that RAU. 2) Distance variables : The distance height between the mat and shoulders in the RBU(32.2cm) to in the MUP(18.3cm) and in the RAU(20.5cm). during that height between the mat and hips in the RBU(48.0cm) to in the MUP(23.4cm), and in the RAU(30.6cm).

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.467-479
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• 2009

The purpose of this study was to present the quantitative data which riders can utilize teaching field by comparison analysis of kinematics according to skill level of rider during 2 strides rising trot with the JeJu's-Horse. Participated subjects was consisted of total 10 riders(unskilled: n=5, skilled: n=5). The method of experiment & analysis was based on 3D cinematography. Variables were consisted of temporal, linear & angular kinematics by each event & phase. The skilled assigned more ratio of elapsed time in air than support phase, had the less range of motion in up-down direction and more consistent velocity in lateral & forward direction and performed periodic up-down movement with alignment in vertical direction according to elapsing of phases. The skilled more flexed at elbow and extended backwardly according to elapsing of phases, while more flexed forwardly at hip & knee and plantarflexion at ankle. The skilled postured backward extension but the unskilled do forward flexion. That is, It was considered that the unskilled continued more unstable posture than the skilled during 2 strides in rising trot.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5766-5772
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• 2011

This study was to investigate the change of gait temporal parameter and ankle joint moment between patients with achilles tendinitis and healthy people. Thus, the purpose of this study is to clarify biomechanical change of gait in patients with achilles tendinitis and to find risk factor for prevention of achilles tendinitis. We recruited 20 patients with an achilles tendinitis and 20 healthy people. While subjects shuttled 5 times on 13 m distance with comfortable pace, we examined gait function marker with three-dimensional gait analysis system. All subject outstepped center of forceplate during gait and calculated ankle joint moment using software. Obtained data was analyzed using SPSS 12.0 software. In results, we confirmed that patients with achilles tendinitis showed reduction of extension moment in early initial phase and reduction of flexion moment in mid-stance on hip joint. and reduction of flexion moment in early initial phase and reduction of extension moment in late phase on knee joint. And we identified that patients with achilles tendinitis showed reduction of dorsiflexion moment in early stance phase, maximal plantarflexion moment in mid stance phase, and dorsiflexion moment in late stance phase. Thus, there are biomechanical changes on gait in patients with achilles tendinitis compared to healthy people. And, in clinical settings, they should focus on changes of gait in patients with achilles tendinitis. Further study will be undertaken for the biomechanical changes of patietns with achilles tendinitis.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.407-415
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• 2014

The purpose of this study is to identify the relation between isokinetic strength of knee extensors and angular velocity of knee joint during fente motion in elite fencers by three disciplines and gender, and to provide the preliminary data for developing the training program and rehabilitation program to enhance sports-performance by three disciplines and gender. Total 31 elite fencers who trained at the national training center of the Korean Olympic Committee (KOC) participated in this study.; 10 fleuret (4 males), 10 epee (6 males) and 11 sabre (5 males). Subjects were measured eccentric and concentric isokinetic strength (PT/BW, WK/BW) of the knee extensors at angular velocity of $60^{\circ}/s$, $180^{\circ}/s$ and $300^{\circ}/s$, and flexion (P1) and extension (P2) angular velocity of knee joint during fente motion. To examine the relationship between isokinetic strength of knee extensor and angular velocity of knee motion, Pearson's correlation coefficient (r). ${\alpha}=.05$ was considered significant. In conclusion, the relationship of isokinetic strength of knee extensors and angular velocity of knee was different depending on three disciplines and gender.