• 한국운동역학회지
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• 제16권1호
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• pp.31-41
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• 2006

The primary purpose of a TKA is to restore normal knee function Therefore, ideally, a TKA should: (a) maintain the natural leverage of the knee joint muscles to ensure generating adequate knee muscle moments to accomplish daily tasks such as rising from climbing stairs; (b) provide adequate knee joint stability. A 16-channel MyoResearch XP EMG system was used to collect the differential input surface electromyography signals VM, VL, RF, BF, ST during climbing/descending stair tests. A Peak Motion Measurement System was used to collect the kinematic and kinetic data. AKIN-COM Ill isokinetic dynamometer was used for EMG of VM, VL, RF, BF and ST during maximal voluntary contraction. I Quadriceps EMG results for the VM of the passed 1year group limb demonstrated significant less RMS EMG than that of the passed 3year group limb $60^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The VL of the passed 1year group limb also demonstrated significants less RMS EMG than that of the passed 3year group limb from $60^{\circ}-45^{\circ}$ of knee flexion(p<0.05). Similar to the VM and VL, the RF of the passed 1year group limb showed less RMS EMG than that of the passed 3year group limb from $60^{\circ}-30^{\circ}$ do knee flexion(p<0.05). Hamstring EMG results for the BF of the passed 1year group limb demonstrated less RMS EMG than that of the passed 3year group limb from $75^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The passed 1year group limb tended to have less ADD displacement(p<0.071) than that of the passed 3year group limb. There was no significant difference of the ABD displacement between the passed 1year group and the passed 3year group limbs(p<0.73). The passed 3year group used compensatory adaptation movement strategies to compensate for the strength deficit of passed 3year group limbs. The passed 3year group limb also increased the quadriceps muscle activation level to produce more knee extension moment to compensate for the short quadriceps moment arm. The passe 3year group limb might have an unstable knee joint in the medio-Iateral direction during the climbing/descending by showing a tendency of more ADD displacement and greater hamming co-activation EMG than the passed 1year group limbs. The TKA design was not able to help the knee joint to produce adequate knee extension moment with less quadriceps muscle effort. I think that old man needs continuous exercise for muscle strength.

• 재활복지공학회논문지
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• 제6권2호
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• pp.15-22
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• 2012

외골격 보행보조로봇은 로봇 시스템을 인체에 직접 착용하는 형태이므로 기구적인 측면에서는 인체 근골격 구조에 최적화된 메커니즘으로 구성되어야 하며, 제어적인 측면에서는 근골격계의 손상을 일으킬 수 있는 로봇의 부적합한 거동을 예방할 수 있는 안전장치를 갖추어야 한다. 외골격 보행보조로봇을 개발하기 위해서는 보행이나 근골격계의 거동특성에 대한 이해 및 분석이 필요하다. 본 연구에서는 최적화된 로봇시스템 설계를 위하여 구동장치의 관절력과 동력 용량을 예측하였으며 몇 가지 보행동작에 대한.관절거동특성을 파악할 수 있는 자료를 획득하였다. 평지보행을 제외한 나타나는 주요한 동작으로는 계단오르고 내리기, 안기, 서기, 경사면 걷기 등이 있다. 본 연구에서는 경사면 걷기를 제외한 모든 동작에 대한 동작 실험을 수행하고 분석하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.84-85
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• 1998

This study was conducted to characterize the gait of a person climbing or descending the stairs. Using our motion analysis system (Vicon 370), gait patterns of ten healthy females (18.8 - 19.6 yrs. old) were measured 1) when a subject tip-toed the stairs, 2) when a subject climbs the stairs with the whole foot, and 3) when a subject went down the stair, respectively. The results of each cases were compared with the data for the level walking collected from 21 healthy females in the previous studies. The stairway gait data can be used as a useful reference in the design of artificial limbs for the lower-limb amputee.

• 동의생리병리학회지
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• 제25권4호
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• pp.715-720
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• 2011

We performed this study to assess pain in patients with knee osteoarthritis. Participants were 120 Patients(men 26 and women 94) with knee osteoarthritis. Pain evaluations were conducted using survey composed of 12 items by interview with oriental medicine doctor. Collected data were analyzed by IBM SPSS Statistics 19.0. Women were 3.8 times more than men(21.7% vs 78.3%). Approximately 80% of participants were overweight and obesity. Descending stair is most painful action for knee osteoarthritis patients. The average degree of knee pain was more than moderate. 5. People diagnosed as arthritis before had the much higher knee pain than never diagnosed before. This study showed female gender, overweight and obesity were associated with the risk of knee arthritis and participants complained knee pain more than moderate. It is hoped that our findings provide information that help the treatment of knee osteoarthritis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.654-670
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• 2020

Workers at construction sites are easily exposed to many dangers and accidents involving falls, tripping, and missteps on stairs. However, researches on construction site monitoring system to prevent work-related injuries are still insufficient. The purpose of this study was to develop a wearable textile pressure insole sensor and examine its effectiveness in managing the real-time safety of construction workers. The sensor was designed based on the principles of parallel capacitance measurement using conductive textile and the monitoring system was developed by C# language. Three separate experiments were carried out for performance evaluation of the proposed sensor: (1) varying the distance between two capacitance plates to examine changes in capacitance charges, (2) repeatedly applying 1 N of pressure for 5,000 times to evaluate consistency, and (3) gradually increasing force by 1 N (from 1 N to 46 N) to test the linearity of the sensor value. Five subjects participated in our pilot test, which examined whether ascending and descending the stairs can be distinguished by our sensor and by weka assessment tool using k-NN algorithm. The 10-fold cross-validation method was used for analysis and the results of accuracy in identifying stair ascending and descending were 87.2% and 90.9%, respectively. By applying our sensor, the type of activity, weight-shifting patterns for balance control, and plantar pressure distribution for postural changes of the construction workers can be detected. The results of this study can be the basis for future sensor-based monitoring device development studies and fall prediction researches for construction workers.

• 한국응급구조학회지
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• 제11권1호
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• pp.11-25
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• 2007

Objective: The purpose of this study was to investigate the effects of combined exercise on the change of postural control, functional status in patients with osteoarthritis of the knee. Methods : The subjects were consisted of 24 women patients fifties and sixties with knee osteoarthritis. Each group had a exercise for 30 minutes per day and three times a week during 8 weeks period. Was used to measure muscular function(60, $180^{\circ}/sec$), postural control. functional capacity(15 M walking test, Rising form a chair test, stair climbing and descending test) and the functional state of a joint(WOMAC). Results: This study results in following 1. In case of muscular function have significantly increased in both groups. 2. There was no significant difference in the postural control of the bilateral between two groups. However, the postural control of a isokinetic exercise program group showed a significant difference in the bilateral side(overall, $M{\cdot}L$ stability index). Especially, the change of postural control in the isokinetic plus postural control exercise program group decreased more significantly in the bilateral(overall, $A{\cdot}P$ stability index). 3 It was significantly decreased in climbing and descending the stairs, and rising from the chair, although functional capacity decreased in lam walking in both groups. 4. The functional state of a joint(WOMAC) showed a significant decrease in both groups. Conclusion : In order to improve the functional status and postural control of patients with osteoarthritis of the knee, performing exercise programming of isokinetic plus balance will be more effective than the exercise program composed of only the isokinetic exercise program.

• 한국정밀공학회지
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• 제23권4호
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• pp.75-82
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• 2006

In this paper, we propose an optimal trajectory for biped robots to move up-and-down stairs using a genetic algorithm and a computed-torque control for biped robots to be dynamically stable. First, a Real-Coded Genetic Algorithm (RCGA) which of operators are composed of reproduction, crossover and mutation is used to minimize the total energy. Constraints are divided into equalities and inequalities: Equality constraints consist of a position condition at the start and end of a step period and repeatability conditions related to each joint angle and angular velocity. Inequality constraints include collision avoidance conditions of a swing leg at the face and edge of a stair, knee joint conditions with respect to the avoidance of the kinematic singularity, and the zero moment point condition with respect to the stability into the going direction. In order to approximate a gait, each joint angle trajectory is defined as a 4-th order polynomial of which coefficients are chromosomes. The effectiveness of the proposed optimal trajectory is shown in computer simulations with a 6-dof biped robot that consists of seven links in the sagittal plane. The trajectory is more efficient than that generated by the modified GCIPM. And various trajectories generated by the proposed GA method are analyzed in a viewpoint of the consumption energy: walking on even ground, ascending stairs, and descending stairs.

• 한국운동역학회지
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• 제23권3호
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• pp.245-252
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• 2013

The purpose of this study was to analyze the effect that various loads have on the lower limb biomechanics. The following variables were measured and analyzed; performance time for each phase, lower limb moments and joint angles, and ground reaction forces. The kinematic and kinetic data was recorded by 2 force platforms and a motion capture system while 12 healthy adults in their twenties stepped down three steps under loads of 0%, 10%, 20% BW. Results are as follows. First, the different loading conditions did not seem to significantly affect the performance times and the joint angles. Second, the largest ground reaction forces were observed at the 1 step at the 10% BW condition. Finally, at the 0% BW loading condition the right hip extension moment was the smallest and the left hip flexion moment was the largest. The results show that there are not any significant changes in the biomechanics of the lower limbs under loading conditions up to 20% BW. Further investigations including more loading conditions with more weights and more additional steps analyzed are needed.

• 한국컴퓨터정보학회논문지
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• 제24권10호
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• pp.33-39
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• 2019

본 논문에서는 인체의 활동량을 측정하기 위해 가속도 센서로 부터 얻은 운동신호를 파라미터로 모델링 하는 방법을 제안한다. 상체와 하체의 움직임이 동시에 일어나지 않는 경우, 현재의 단체널 방식의 운동량 분석방법은 많은 오차를 수반하게 된다. 본 연구에서는 3축 가속도 센서를 팔과 다리에 부착하고 인체의 활동을 측정한 후, 각 채널 별로 팔과 다리의 운동량을 계산하고, 채널별로 선형예측계수를 얻는다. 또한, 상체와 하체운동간의 교차상관도를 측정함으로써 상체와 하체의 주기성을 판단하게 된다. 선형예측계수와 주기 값은 운동의 종류와 이에 따른 운동량을 측정하는 자료로 이용하게 된다. 결과에서 제안한 방법의 유효성을 확인하기 위해 계단내려가기, 계단오르기, 언덕오르기, 언덕내려가기 등의 4가지 운동을 측정하여, 제시한 파라미터 모델의 유용성을 확인한다.

• Physical Therapy Rehabilitation Science
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• 제7권2호
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• pp.61-66
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• 2018

Objective: Patellofemoral pain syndrome (PFPS) is a condition that is characterized by patellar discomfort or pain that is aggravated during certain activities such as ascending/descending stairs. The Patellofemoral Disability Index (PDI) was developed to assess the effect of pain on functional activities in individuals with PFPS. The objectives of the current study were to determine the internal consistency, test-retest reliability, and validity of this index. Design: Cross-sectional study. Methods: Forty-one subjects who had PFPS with a mean age of $28.8{\pm}5.0years$ and a mean body mass index of $25.6{\pm}4.7kg/m^2$ participated in the study. All subjects were concurrently enrolled in a clinical trial for which they were instructed to complete hamstring-resistance exercises for 4 weeks. Over the course of the intervention, they completed both the PDI and the Oswestry Disability Index (ODI) at baseline after two weeks, and after four weeks. Pearson correlation coefficient was used to assess the criterion validity. Cronbach's ${\alpha}$ was used to examine the internal consistency. Intraclass correlation coefficients with 95% confidence interval were computed to examine test-retest reliability. Results: Subjects' responses within both the PDI and the ODI yielded Pearson correlation coefficient values that were positive and highly significant (range, 0.73-0.97; p<0.001). There was a high level of internal consistency (Cronbach's ${\alpha}{\geq}0.8$), with the exception of stair climbing (Cronbach's ${\alpha}=0.65$). Intraclass correlation ranged from 0.87 to 0.92, indicating high levels of test-retest reliability. Conclusions: The PDI is a valid, reliable, and feasible method of assessing pain and functional ability in patients with PFPS.