• 생명과학회지
• /
• 제14권3호
• /
• pp.484-489
• /
• 2004

인공관절은 21세기 정형외과 발전의 주요변화들 중의 하나이다. 1997년이래 전 세계적으로 무릎인공관절(Total Knee Arthroplasty: TKA)을 사용하는 사람들이 해마다 약 600,000명씩 증가하고 있는 추세이고 미국에서만 인공관절을 사용하고 있는 사람들이 210,000명에 달하고 있으며 그 시장은 대략 $5 billion을 넘고 있다(7). 무릎인공관절은 일상생활에서 의자에 앉았다 일어날 때 계단을 올라 갈 때 등, 무릎의 근 모멘트가 적당한 활동을 해서 무릎관절 근육에 지레와 같은 작용을 하게 하고, 완전한 무릎으로 정상인의 무릎과 같은 기능을 오랫동안 유지하게 한다. 이러한 목적을 달성하기 위해서는 무릎인공관절 디자인 시 정상적인 무릎 회전축(normal knee's axes of rotation)들의 정확한 위치를 파악하는 것은 중요하다. 인공관절 수술 후 무릎관절의 신전과 굴곡 운동을 하는 동안 하나의 회전축(single-axes)을 가진 하나의 회전 반경(single-radius)을 알아보는 것은 여러 축(multi-axes)으로 움직이게 된다는 다축 회전반경(multi-radius)을 분석하기에 앞서 중요한 연구이다. 따라서 본 연구에 서는 무릎이 신전운동과 굴곡 운동 시 신전과 굴곡 모멘트를 만들어내는 대퇴 사두근(quadriceps muscle)과 무릎 오금근 (hamstring)의 역할을 알아보았고, 또한 모멘트와 대퇴 사두근의 iEMG 형태를 파악하였다. 본 연구를 수행하기 위해 무릎인공관절 수술을 받고 1년과 3년이 지난 정상적인 생활을 하는 피검자(1년2명, 3년2명)를 대상으로 Isometric 테스트를 위한 KIN-COM III을 사용하여 60$^\circ$, 30$^\circ$의 무릎굴곡 측정을 하였고, Isokinetic concentric 테스트를 위해서 무릎굴곡각도의 $10^\circ$-80$^\circ$까지 움직임을 측정하였다 또한 15$^\circ$-75$^\circ$까지의 신전운동(sit-to-stand movement)과 굴곡운동(stand-to-sit movement)을 실시하여 시간의 차이, 내전과 외전의 차이 그리고 iEMG의 차이를 알아보았다. 본 연구의 데이터는 여러 번의 실험을 통하여 가장 일반적인 수치를 사용하였다. 이 때 16-channel BTS TELEMG를 사용하여 대퇴사두근과 무릎오금근의 근육활동모양을 알아보았다. 본 연구결과는 시술 후 3년이 지나면서 TKR (Total Knee Replacement)의 대퇴 사두근 토큐가 약해지는 것으로 나타났고, iEMG 실험에서는 N-TKR (Non-Total Knee Replacement)의 대퇴 사두근이 TKR의 대퇴 사두근 보다 근 수축력이 더 크게 발휘되는 것으로 밝혀졌다. 단축회전반경의 굴곡과 신전의 $10^\circ$-80$^\circ$까지의 각 속도는 굴곡동작이 1.19s, 신전 동작이 1.68s로 나타났다. 굴곡과 신전동작에서 다리의 외전(abduction)의 각도변화는 굴곡 시 5.5$^\circ$, 신전 시 5.2$^\circ$로 나타났고, 내전(adduction)의 각도변화는 굴곡 시 7.2$^\circ$, 신전 시 6.1$^\circ$로 나타났다. 대퇴 사두근의 iEMG변화에서는 15$^\circ$-60$^\circ$까지 vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF) 모두 굴곡동작에서 큰 값으로 나타났고, 61$^\circ$-75$^\circ$사이에서는 신전동작에서 iEMG가 큰 값으로 나타났다. 이와 같은 결과들은 인공관절 수술자들의 다축회전 반경을 분석하기에 앞서 중요한 선행연구가 될 것으로 생각된다.

• 대한디지털의료영상학회논문지
• /
• 제12권1호
• /
• pp.43-50
• /
• 2010

The representative study of Patellofemoral Joint Merchant method can show the view for inspection of the sulcus angle, congruence angle and diagnose whether there are the vertical fractures and recognize the degree of dislocation and patella subluxation. However, anatomical correlation about the degree of knee joint curvature changes during position adjustment and distortion of the image reduces reproducibility. In order to resolve these problems, Merchant method needs to use assisting device which reduces the occurrence of repeat projection and effectively to increase unification of examination and the consistency of the image. However, there are disadvantages for patients who take other examinations. For example, they have to change the position for every examination and it might cause the patient's discomfort and increase of examination time. In this study, we newly devised commercial assisting device which improves the reproducibility of the images and reduces inconvenience of patients movement. Further research should be taken to obtain a image without patient's movement and to reduce the time of the examination than existing method.

• 한국정밀공학회지
• /
• 제21권11호
• /
• pp.209-218
• /
• 2004

The purpose of this paper is to suggest a practical and simple method for the identification of the joint mechanical properties and to apply it to human knee joints. The passive moment at a joint was modeled by three mechanical parts, that is, a gravity term, a linear damper term and a nonlinear spring term. Passive pendulum tests were performed in 5 fat and 5 thin men. The data of pendulum test were used to identify the mechanical properties of joints through sequential quadratic programming (SQP) with random initial values. The identification was successful where the normalized root-mean-squared (RMS) errors between the simulated and experimental joint angle trajectories were less than 10％. The parameter values of mechanical properties obtained in this study agreed with literature. The inertia, gravity and the damping constant were greater at fat men, which indicates more resistance to body movement and more energy consumption fer fat men. The suggested method is noninvasive and requires simple setup and short measurement time. It is expected to be useful in the evaluation of joint pathologies.

• Safety and Health at Work
• /
• 제13권3호
• /
• pp.315-325
• /
• 2022

Background: Firefighters are required to carry self-contained breathing apparatus (SCBA), which increases the risk of musculoskeletal disorders. This study assessed the newly recruited firefighters' internal forces and potential musculoskeletal disorders when carrying SCBA. The effects of SCBA strap lengths were also evaluated. Methods: Kinematic parameters of twelve male subjects running in a control condition with no SCBA equipped and three varying-strapped SCBAs were measured using 3D inertial motion capture. Subsequently, motion data and predicted ground reaction force were inputted for subject-specific musculoskeletal modeling to estimate joint and muscle forces. Results: The knee was exposed to the highest internal force when carrying SCBA, followed by the rectus femoris and hip, while the shoulder had the lowest force compared to the no-SCBA condition. Our model also revealed that adjusting SCBA straps length was an efficient strategy to influence the force that occurred at the lumbar spine, hip, and knee regions. Grey relation analysis indicated that the deviation of the center of mass, step length, and knee flexion-extension angle could be used as the predictor of musculoskeletal disorders. Conclusion: The finding suggested that the training of the newly recruits focuses on the coordinated movement of muscle and joints in the lower limb. The strap lengths around 98-105 cm were also recommended. The findings are expected to provide injury interventions to enhance the occupational health and safety of the newly recruited firefighters.

• 대한정형도수물리치료학회지
• /
• 제24권1호
• /
• pp.39-46
• /
• 2018

Background: In most human lives, 80 percent have problems with the ankle and can be solved with a treatment that is objective in proper assessment. Discrepacts in the ankle are also associated with walking patterns and affect hip and knee joints. An evaluation of hip flexion and extensor muscles was performed to check the strength of hip joints after ankle sprain patients application of arthesis. Methods: In the hospital in Bucheon, 20 outpatients who visited the hospital for treatment with ankle sprain were tested with 10 male and 10 female patients. The criteria for selection of the study subjects were randomly divided into those with joint movement techniques applied to the ankle joints and those with conservative physical therapy. Results: In applying arthrography and preservation physical therapy to patients with ankle sprain, a difference in muscle strength between hip flexion and extensor was noted in post-evaluation comparisons. There were significant differences in the assessment of walking speed and walking time between the two counties in the gait analysis assessment (p<.05). Conclusion: Studies have shown that applying arthrography to people with ankle sprain has a greater therapeutic effect than using conservative physical therapy.

• 대한의용생체공학회:의공학회지
• /
• 제28권2호
• /
• pp.218-228
• /
• 2007

Modem concepts of gait rehabilitation after stroke favor a task-specific repetitive approach. In practice, the required physical effort of the therapists limits the realization of this approach. Therefore, a mechanized gait trainer enabling nonambulatory patients to have the repetitive practice of a gait-like movement without overstraining therapists was constructed. In this study, we developed an active gait training system for patients with gait disorder. This system provides joint movements to patients who cannot carry out an independent gait. It provides a normal stance-swing ratio of 60:40 using an eccentric configuration of two gears. Joint motions of the knee and the ankle were evaluated with using the 3D motion analysis system and compared with the results from the multi-body dynamics simulation. In addition, clinical investigations were also performed for low stroke patients during the 6-week gait training. Results from the dynamics simulation showed that joint movements of the knee and the ankle were affected by the gear size, the step length and the length of the foot plate, except the radius of curvature of the foot guide plate. Also, the 6-week gait training revealed relevant improvements of the gait ability in all low subjects. Functional ambulation category levels of subjects after training were 2 in three patients and 1 in a patient. The developed active gait trainer seems feasible as an adjunctive tool in gait rehabilitation after stroke.

• PNF and Movement
• /
• 제15권1호
• /
• pp.1-11
• /
• 2017

Purpose: The purpose of this study was to use an ICF tool in an intervention for anterior cruciate ligament reconstruction (ACLR) patients to examine and evaluate the patients' functional problems, measure the results of the intervention, and present the process of preparing proprioceptive neuromuscular facilitation (PNF) intervention strategies, thereby contributing to changes in and development of relevant future clinical practices. Methods: A PNF rehabilitation exercise program using an ICF tool was applied to ACLR patients five times per week for four weeks. To measure the resulting changes, the ICF evaluation display, the visual analog scale (VAS), the manual muscle test (MMT), the range of motion (ROM) test, the Lysholm knee score (LKS), and the muscle endurance test (MET) were used. Results: After the intervention was applied to the ACLR patients, improvements were achieved in all the tests: ICF evaluation display, VAS, MMT, ROM, LKS, and MET. Conclusion: Utilizing the ICF tool, this study identified functional problems of ACLR patients. When the intervention was applied, physical functions improved, and structural damage was reduced, leading to enhanced levels of functional activities such as postural changes, posture maintenance, gait, movements, and movements between different places. The patients were able to complete the teacher training, which was their goal.

• 한국의상디자인학회지
• /
• 제23권2호
• /
• pp.79-91
• /
• 2021

This study aims to rectify the disfigurement of bowlegged, (which means they have a gap between knees due to knee joint problems) females in their twenties through the development of pants patterns. The contents of the study are as follows: First, two types of basic pattern-making methods were selected. Two mock-ups, which were made by using these pre-selected basic patterns, were worn by three bowlegged participants and evaluated with a fit test. A basic pattern, which had good body fit was selected, which had a bubble or a wedge at in crotch area and roomy or snug upper thigh. Second, the mock-up, which was made by using the selected basic pattern, led to the outward movement of crease lines. Two types of patterns that were adjusted were evaluated through a fit test. As a result, an effective adjustment for moving the crease line to the outside or to the center was to cut along the slash line of a horizontal balance line to, but not through the crotch seam to spread the pattern at the hip. Third, three patterns were readjusted using the chosen alteration pattern, and the crotch seam and spread patterns of 1 cm, 2 cm, and 3 cm at the hip were applied. As a result of the evaluation of the fit test, three participants-the majority-showed a better fit when the spread amount in the pattern was 2 cm, although every participant did have a different gap between the knees. This study has significance in which rectifies the disfigurement of bowlegged individuals through the development of patterns for females in their twenties who are bowlegged.