• 한국전문물리치료학회지
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• 제22권3호
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• pp.33-40
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• 2015

The purpose of this study was to investigate the effect of multi joint-joint position sense (MJ-JPS) training on joint position sense, balance, and gait ability in stroke patients. A total of 18 stroke patients participated in the study. The subjects were allocated randomly into two groups: an experimental group and a control group. Participants in the experimental group received MJ-JPS training (10 min) and conventional treatment (20 min), but participants in the control group only received conventional treatment (30 min). Both groups received training for five times per week for six weeks. MJ-JPS is a training method used to increase proprioception in the lower extremities; as such, it is used, to position the lower extremities in a given space. MJ-JPS measurement was captured via video using a Image J program to calculate the error distance. Balance ability was measured using Timed Up and Go (TUG) and the Berg Balance Scale (BBS). Gait ability was measured with a 10 m walking test (10MWT) and by climbing four flights of stairs. The Shapiro-Wilk test was used to assess normalization. Within-group differences were analyzed using the paired t-test. Between-group differences were analyzed using the independent t-test. The experimental group showed a significant decrease in error distance (MJ-JPS) compared to the control group (p<.05). Both groups showed a significant difference in their BBS and 10MWT results (p<.05). The experimental group showed a significant decrease in their TUG and climbing results (p<.05), but the control group results for those two tasks were not found to be significant (p>.05). There was significant difference in MJ-JPS and by climbing four flights of stairs on variation of pre and post test in between groups (p<.05), but TUG and BBS and 10MWT was no significantly (p>.05). We suggest that the MJ-JPS training proposed in this study be used as an intervention to help improve the functional activity of the lower extremities in stroke patients.

• 한국전자통신학회논문지
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• 제8권9호
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• pp.1383-1389
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• 2013

본 연구는 불안정지지면 훈련을 통한 발목관절위치감각의 변화와 동요면적 변화간의 상관관계를 알아보고자 실시하였다. 건강한 성인 남녀 48명을 대상으로 무작위로 불안정지지면군(n=24)과 안정지지면군(n=24)으로 나누어 동일한 운동 프로그램을 적용하여 주 3회씩 6주 동안 실시하였다. 불안정지지면군은 균형운동 패드에서, 안정지지면군은 단단한 지면에서 운동을 실시하였다. 운동 전 후에 발목관절위치감각의 변화와 동요면적의 변화를 알아보았다. 그 결과, 불안정지지면군에서 발목관절위치감각 오차와 동요면적은 유의하게 감소하였다(p<.05). 그리고 불안정지지면군에서만 발목관절위치감각 오차의 변화량과 동요면적 변화량간의 유의한 상관관계를 보였다. 따라서 본 연구는 불안정지지면에서의 고유수용성감각 운동을 통해 발목관절위치감각 변화와 동요면적 변화간의 유의한 상관관계가 있음을 알 수 있었다.

• 대한물리의학회지
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• 제8권4호
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• pp.619-625
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• 2013

PURPOSE: The purpose of this study was to determine the effects of muscle fatigue on knee joint position sense in the young, elderly adults, and stroke patients. METHODS: The subjects were recruited into three groups; young group(YG)(N=15), elderly group(EG)(N=15), and stroke group(SG)(N=15). Exercise-induced fatigue was achieved by repeated active exercise 60 times on an angle at 10 to 100 degrees of the knee joint with an angle speed of $120^{\circ}/s$, with three sets for 15 minutes. Evaluation was performed for determination of repositioning error using passive angle repositioning (PAR) and active angle repositioning (AAR). RESULT: Regarding the error score for the knee joint position sense in both the baseline and muscle fatigue, significant increases were observed between the YG and EG (p<.05), and between the EG and SG (p<.01), and between YG and SG (p<.05) in the PAR, YG and SG (p<.05) in the AAR. CONCLUSION: In particular, the results of this study indicate that management and intervention for elderly adults and stroke patients can result in improvement of proprioception.

• 전기학회논문지
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• 제58권1호
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• pp.203-209
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• 2009

The purpose of this study is to develop a minimally constraint joint angle measurement system for the feedback control of FES (functional electrical stimulation) locomotion. Feedback control is desirable for the efficient FES locomotion, however, the simple on-off control schemes are mainly used in clinic because the currently available angle measurement systems are heavily constraint or cosmetically poor. We designed a new angle measurement system consisting of a magnet and magnetic sensors located below and above the ankle joint, respectively, in the rear side of ipsilateral leg. Two magnetic sensors are arranged so that the sensing axes are perpendicular each other. Multiple positions of sensors attachment on the shank part of the ankle joint model and also human ankle joint were selected and the accuracy of the measured angle at each position was investigated. The reference ankle joint angle was measured by potentiometer and motion capture system. The ankle joint angle was determined from the fitting curve of the reference angle and magnetic flux density relationship. The errors of the measured angle were calculated at each sensor position for the ankle range of motion (ROM) $-20{\sim}15$ degrees (dorsiflexion as positive) which covers the ankle ROM of both stroke patients and normal subjects during locomotion. The error was the smallest with the sensor at the position 1 which was the nearest position to the ankle joint. In case of human experiment, the RMS (root mean square) errors were $0.51{\pm}1.78(0.31{\sim}0.64)$ degrees and the maximum errors were $1.19{\pm}0.46(0.68{\sim}1.58)$ degrees. The proposed system is less constraint and cosmetically better than the existing angle measurement system because the wires are not needed.

• 대한통합의학회지
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• 제8권2호
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• pp.139-147
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• 2020

Purpose : Proprioceptive position sense plays a key role in providing joint stability, and multiple factors are related to proprioceptive position sense. Thus, this study aimed to determine the effects of body composition, particularly skeletal muscle mass on proprioceptive position sense following muscle fatigue. Methods : Healthy female subjects agreed to have their body composition analyzed. Only subjects who had 18.5-22.9 kg/㎡ of BMI (body mass index) were included in this study, and the participants were divided into two groups by skeletal muscle mass level. The experimental group had a level of skeletal muscle lower than the standard level (n=9), while the control group showed a standard or high level of skeletal muscle mass (n=11). To determine the change in proprioceptive position sense of the knee joint, the absolute angle error (AAE) was evaluated following muscle fatigue on low extremity. The muscle fatigue was induced by isokinetic resistance exercise program of Biodex system. AAE was measured by the Biodex system and compared the result before and after muscle fatigue. Results : The experimental group showed a significant AAE difference between before (3.16±2.48 °) and after (5.40±2.61 °) muscle fatigue. In addition, there was a AAE difference between the experimental (5.40±2.61 °) and control groups (3.53±1.67 °) after fatigue; however, there was no significance. Those results indicated that low level of skeletal muscle mass might influence the proprioceptive position sense of the knee joint after muscle fatigue. Conclusion : Thus, maintaining the proper level of skeletal muscle mass is pivotal to reduce the risk of injury following muscle fatigue in ADL or sport activities.

• 제어로봇시스템학회논문지
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• 제6권2호
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• pp.190-196
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• 2000

A hybrid position/force control scheme to regulate the force and position by dual arms is proposed where two arms are treated as one rm in a kinematic viewpoint. The force error calculated from the information of two force/torque sensors attached to the end of each arm is transferred to minimum configuration space coordinates and then is distributed to total system joint coordinates, The position adjustment at the total con-figuration coordinates is computed based on the effective compliance matrix with respect to total joint coordinates which is obtained by coordinate transformation between the task coordinates and the total joint coordinates. The proposed scheme is applied to sawing task. When the trajectory of the saw is planned to follow a line in a horizontal plane 2 position parameters are to be controlled(i.e., two translational positions) Also a certain level of contact force has to be controlled along the vertical direction(i.e. minus z-direction) not to loose the contact with the object to be sawn. We experimentally show that the performance of the velocity and force response are satisfactory. The proposed hybrid control scheme can be applied to arbitrary two cooperating arm system regardless of their kinematic structure and the number of actuated joints.

• 한국전문물리치료학회지
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• 제28권4호
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• pp.256-265
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• 2021

Background: Individuals with scapular winging may have proprioceptive dysfunction which is important for motor control and causes shoulder instability. Reduced serratus anterior (SA) and lower trapezius (LT) muscle activity accompanied by over-active upper trapezius (UT), and pectoralis major (PM) may be contributing factors. Flexi-bar (FB) exercise may be used to increase joint position sense (JPS) and alter the target muscle activities. Objects: This study aimed to investigate the immediate effects of flexi-bar exercise prior to knee push-up plus (FPK) versus knee push-up plus (KPP) on JPS and muscle activity of SA, LT, UT, and PM in subjects with scapular winging. Methods: Eighteen subjects with scapular winging were recruited. JPS was investigated at baseline, after KPP and after FPK. Passive and active JPS errors were calculated by isokinetic equipment. Surface electromyography was used to record muscle activities during KPP and FPK. One-way repeated-measures analysis of variance and post hoc analyses were used to analyze the JPS error measured at baseline, after KPP and after FPK. Paired t-tests were used to compare muscle activities between KPP and FPK. Results: Passive JPS error was significantly decreased after KPP (p = 0.005) and after FPK (p = 0.003) compared to the baseline. Active JPS error was also significantly decreased after KPP (p = 0.016) and after FPK (p = 0.012) compared to the baseline. There was no significant difference in the passive and active JPS errors between KPP and FPK. SA activity during FPK was significantly increased (p = 0.024), and LT activity during FPK was significantly increased (p = 0.006). There were no significant differences in the UT and PM activity. Conclusion: FB might be recommended to immediately improve passive and active JPS and to selectively increase SA and LT muscle activities during KPP in individuals with scapular winging.

• Physical Therapy Rehabilitation Science
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• 제9권1호
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• pp.25-35
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• 2020

Objective: To compare the effects of joint mobilization, gym ball exercises, and breathing exercises on breathing pattern disorders and joint position sense in persons with chronic lower back pain. Design: Three-group pretest-posttest design. Methods: Thirty-six individuals with chronic low back pain who were undergoing a postural correction and vertebral movement at a rehabilitation center participated in this study. The subjects were randomly divided into the joint mobilization group (n=12), gym ball exercises group (n=12), and the breathing exercises group (n=12). The exercises were applied for 40 minutes a day, twice a week for a total of 12 weeks. Measurement tools included the end-tidal CO₂ (ETCO₂), respiration rate (RR), breath hold time, Nijmegen Questionnaire (NQ), excursion, and joint position error (JPE). Results: The groups showed significant differences in the ETCO₂, RR, NQ, Excursion and JPE test before and after the intervention (p<0.05). The differences between the groups were significant in the group that received the gym ball and breathing exercises in ETCO₂ and RR (p<0.05). The differences between the groups were most significant in the group that received breathing exercises in NQ and excursion (p<0.05). The differences between the groups were significant in the group that received the gym ball and breathing exercises in JPE Lt. and Rt. (p<0.05). Conclusions: All three interventions had a significant impact on the biomechanical changes, respiratory variables, and joint position sense in participants with chronic lower back pain. Breathing exercises were found to be particularly effective in improving respiratory parameters.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.192-194
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• 2006

Backlash between meshing gear teeth causes impact, tracking error and undesired vibrations. It is usually minimized by precision gear, spring-loaded anti-backlash gears and precise mechanical adjustment. Although these techniques can help to reduce the backlash gap, its cost is relatively high and performance is limited. And the classic controller is insufficient to control the dynamic system with nonlinearity. For these reason, a fuzzy controller is proposed to compensate the backlash effect at a robot system. The input variables are position error and change in error. The output variable can be defined by input voltage of motor. The performance of a fuzzy controller is verified by comparing with a PID controller. The results show that the undesired vibration is suppressed. And then diminishing the position error is observed.

• 한국전문물리치료학회지
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• 제12권1호
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• pp.22-27
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• 2005

The purpose of this study was to investigate the effects of visual information and different elevations of medially wedged insoles on the proprioceptive sense of the knee joint. The subjects of this study were 16 able-bodied men who were not athletic. An electrogoniometer was used to determine the error value between calculated 50% of full flexion (target position) and performed 50% of full flexion in a standing position with the upper extremities crossed. Tests were randomly performed in $2{\times}4$ conditions. Visual variations included open eyes vs. closed eyes, while the elevation was adjusted through the use (or lack thereof) of medially wedged insoles of 10 mm, 14 mm, and 18 mm. The average error value in each condition was statistically analyzed. The findings of this study revealed as follows: 1) The average error value was significantly higher with the subjects' eyes open than with their eyes closed (p<.05). 2) The averaged error value was also significantly higher when the subjects were elevated 18 mm than with no elevation at all (p<.05). The findings of this study should be considered in lower extremity rehabilitation programs when medially wedged insoles used.