• PNF and Movement
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• 제13권2호
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• pp.95-102
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• 2015

Purpose: The purpose of this study was to analyze the effect of arm flexion patterns of proprioceptive neuromuscular facilitation on muscle activation in the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used. Methods: This study used an electromyogram (MP150, Biopac Systems, USA) to measure muscle activation in 20 healthy male students. Comparative analysis was completed on muscle activation of the vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius of the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used with a unilateral arm flexion-abduction-external rotation pattern. Paired t-tests using the SPSS 12.0 for Windows analyzed the data produced by the electromyogram. Results: There was a statistically significant difference in muscle activation in the biceps femoris, gastrocnemius, and tibialis anterior when the open kinematic chain and closed kinematic chain positions were compared (p < 0.05). Conclusion: The biceps femoris, gastrocnemius, and tibialis anterior muscles showed greater muscle activation in the closed kinematic chain position when compared to the open kinematic chain position.

• 대한물리의학회지
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• 제4권2호
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• pp.93-100
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• 2009

Purpose：The purpose of this study was to examine the effects of self-controlled knowledge of result (KR) versus the yoked KR on learning of knee joint proprioception. Methods：Forty volunteer subjects (20 men and 20 women) were randomly assigned to each four groups: 1) self-controlled KR in open kinematic chain, 2) yoked KR in open kinematic chain, 3) self controlled KR in close kinematic chain, and 4) yoked KR in close kinematic chain. The difference between the angle of position and reproduction angle was determined as a proprioception error and measured using an angle reproduction test. The subjects in self-controlled groups were provided with feedback whenever they requested it, whereas the subjects in yoked groups were not provided with feedback. The data were analyzed using a one-way ANOVA. Results：The proprioception errors in close kinematic chain groups decreased significantly compared with those in close kinematic chain groups(p<.05). The proprioception errors in the self-controlled group decreased significantly compared with those in yoked groups during acquisition and retention test(p<.05). Conclusion：Self-controlled knowledge of result during open kinematic chain movement is considered to be a good method on motor learning.

• PNF and Movement
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• 제9권4호
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• pp.13-21
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• 2011

Purpose : The purpose of this study was to analyze the effect of closed kinematic chain exercise and proprioceptive neuromuscular facilitation exercise on the static dynamic balance performance of hemiplegic patients in order to suggest them therapeutic intervention methods. Methods : The subjects of this study were 18 hemiplegic patients grouped into 2 subgroups according to the exercise program. one group of closed kinematic chain exercise carried out sit to stand, Hooklying with pelvic lift(bridging) and stair-up & down by a hemiplegic leg. The other group of proprioceptive neuromuscular facilitation exercise carried out leg flexion-extension pattern in supine position, leg flexion pattern in standing and stabilizing reversal exercise in stating position. Each exercise was carried out over 3 sets of 10reps. Results : The results of this study were summarized as follows: 1. For both groups, there were statistically significant changes in the static balance (FICSIT-4) performance after exercise program (p<.05). 2. For both groups, there were statistically significant changes in the dynamic balance (FSST, TUG, FRT) performance after exercise program (p<.05). 3. In the comparison between both groups, there was no statistically significant difference in the static dynamic balance performance (FICSIT-4, FSST, TUGT, ER) after exercise program. Conclusion : As the results of the study shows closed kinematic chain exercise and proprioceptive neuromuscular facilitation exercise affect the improvement of hemiplegic patients'' static dynamic balance performance, it is supposed that these exercises could be therapeutic exercise program in clinical situations.

• PNF and Movement
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• 제15권3호
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• pp.237-246
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• 2017

Purpose: The purpose of this study was to investigate the effects of forward-and-backward shift trunk exercise using a proprioceptive neuromuscular facilitation (PNF) diagonal pattern in a closed kinematic chain exercise on the upper limb function and activity of daily living (ADL) in a stroke patient. Methods: One subject participated in this study. The study used a reversal A-B-A' design, where A and A' were the baseline period (no intervention), and B was the intervention period. The intervention was a forward-and-backward trunk shift exercise, using a PNF diagonal pattern on both a stand-on-hand position and a quadruped position of closed kinematic chain exercises, for 20 min per day for 2 weeks. The range of motion (ROM) of the shoulder joint was measured and a Fugl-Meyer assessment of upper extremity (FMA-UE) and a functional independence measure (FIM) were performed to measure upper limb function and activity of daily living (ADL). Results: ROMs of shoulder joint (flexion, extension, abduction, and external rotation) increased in the intervention phase. The FMA-UE score increased (from 28 to 36) in the intervention phase. The FIM score increased (from 20 to 25) in the intervention phase. These increases were maintained after intervention (Baseline II). Conclusion: These results suggest that forward-and-backward shift trunk exercises using a PNF diagonal pattern in a closed kinematic chain exercise have a positive effect on stroke patients' upper limb function and ADL ability.

• 한국정밀공학회지
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• 제22권11호
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• pp.72-81
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• 2005

A new spherical-type 3-degree-of-freedom parallel mechanism consisting of a two degree-of-freedom parallel module and a serial module is proposed. Two alternative designs for the serial sub-chain are suggested and compared. The first design employs RU joint arrangement for the serial sub chain structure. The second design incorporates a gear chain to drive the distal revolute joint of the serial sub-chain from the base platform of the mechanism. This modification significantly improves kinematic characteristics of the mechanism within its workspace. Firstly, the closed-form solutions of both the forward and the reverse position analysis are derived. Secondly, the first-order kinematic model with respect to three inputs which are located at the base is derived. Thirdly, it is confirmed through simulation that the modified mechanism has much more improved isotropic characteristic throughout the workspace of the mechanism. Lastly, the proposed mechanism is implemented to verify the results from this analysis.

• 한국정밀공학회지
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• 제22권8호
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• pp.118-127
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• 2005

A spatial 3 degrees-of-freedom mechanism employing Stewart Platform structure is proposed: the mechanism maintains the 3- RRPS structure of Stewart Platform but has an additional passive PRR serial sub-chain at the center area of the mechanism in order to constrain the output motion of the mechanism within the output motion space of the added PRR serial subchain. The forward and reverse position analyses of the mechanism are performed. Then the mechanism having both the forward and the reverse closed-form solutions is suggested and its closed form solutions are derived. It is confirmed, through the kinematic analysis of those two proposed mechanisms via kinematic isotropic index, that both the proposed mechanisms have fairly good kinematic characteristics compared to the existing spatial 3-DOF mechanisms in literature.

• 한국산업융합학회 논문집
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• 제17권3호
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• pp.84-92
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• 2014

In this paper, a novel 5-axis hybrid-kinematic machine tool is introduced and the research results on accuracy improvement of the prototype machine tool are presented. The 5-axis hybrid machine tool is made up of a 3-DOF parallel manipulator and a 2-DOF serial one connected in series. The machine tool maintains high ratio of stiffness to mass due to the parallel structure and high orientation capability due to the serial-type wrist. In order to acquire high accuracy, the methodology of measuring the output shafts by additional sensors instead of using encoder outputs at the motor shafts is proposed. In the kinematic view point, the hybrid manipulator reduces to a serial one, if the passive joints in the U-P serial chain at the center of the parallel manipulator are directly measured by additional sensors. Using the method of successive screw displacements, the kinematic error model is derived. Since a ball-bar is less expensive than a full position measurement device and sufficiently accurate for calibration, the kinematic calibration method of using a ball-bar is presented. The effectiveness of the calibration method has been verified through the simulations. Finally, the calibration experiment shows that the position accuracy of the prototype machine tool has been improved from 153 to $86{\mu}m$.

• 한국운동역학회지
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• 제15권4호
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• pp.97-104
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• 2005

Previous studies of kinematic analysis of golf swing usually dealt with variations vertically. The purpose of the study was to examine the horizontal hip joints motion of the fifteen male professional golfers during driver swinging. Kinematic variables were calculated by the Kwon3D motion analysis program. Paired t-tests and one-way ANOVA were used to compare the hip height, distance, displacement, and position differences. Results showed that there were no hip height changes and no hip height differences between left and right hip from address to impact. The axis of the backswing was braced right hip, the axis of the downswing was moving left hip. Hips position at the top of the backswing showed that hips move to target prior to hands, which means the sequential motion of the chain linked body segments. From address to impact, left hip moving distance was longer than right hip(p<.001), but during the whole swing, right hip moving distance was longer than left hip(p<.001). Hip rotation angle to target line was $-48.14{\pm}9.32^{\circ}$ at top of the backswing, $40.88{\pm}8.44^{\circ}$ at impact, and $104.70{\pm}8.14^{\circ}$ at finish.

• 대한물리의학회지
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• 제9권3호
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• pp.249-253
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• 2014

PURPOSE: This study intends to examine the effects of change of anatomical position of the ankle joint in open kinematic chain, an appropriate position for selective muscle training, on vastus lateralis obliques, rectus femoris, vastus medilais obliques, and rectus abdominalis muscle activation and to present an effective method of muscle training for patients and normal people. METHODS: The participants of this study were Korean healthy adult in their 20s. The 8 channel surface electromyography was used to measure muscle activation while the subjects raised their legs under each condition. Under each condition, while the subjects raised the leg to hip joint flexion at $60^{\circ}$ along the arch. RESULTS: The analysis result of muscle activation by each section and position during leg rising. There were significant differences. CONCLUSION: For independent strengthening of each muscle, muscle activation was measured according to leg raising angles and the result differed according to each section and position. If this study result is applied to muscle training for patients who need selective muscle training, more effective muscle strengthening will be made possible.

• 한국산학기술학회논문지
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• 제17권2호
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• pp.299-306
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• 2016

본 논문에서는 센서 네트워크를 이용하여 의사의 동작을 흉내 낼 수 있는 내시경 취급로봇의 형상 예측방법이 제안된다. 3축 지자기계와 3축 가속도 계로 이루어진 단위센서가 CAN버스 통신을 통하여 네트워크를 구성한다. 각각의 센서 유니트는 연성 튜브로 만들어진 로봇의 길이방향 위에 있는 점들의 각들을 검출하는 데 사용된다. 센서 네트워크로부터 수신된 신호들은 Butterworth lowpass filter를 이용하여 필터링 된다. 여기서 우리는 노이즈 제거를 위하여 버터워쓰 필터를 설계하였다. 최종적으로 로패스 필터에 의하여 노이즈가 걸러진 신호들을 처리하여 Euler 각이 추출된다. 이 Euler 각을 이용하여 sensor network 상에 있는 각 센서의 위치가 추정된다. 우리는 로봇 바디가 링크와 관절들로 구성되어 있다고 가정한다. 그러면 각 센서의 위치는 각 링크의 중심에 부착되어 있는 것으로 가정할 수 있다. Euler 각과 kinematics chain model로부터 링크의 위치를 결정할 수 있다. 각 링크를 매끈하게 연결할 수 있도록 하기 위해 각 센서의 위치사이에 보간이 수행되어 최종적으로 작동 중에 있는 내시경의 최종형상이 얻어진다. 실험 결과는 제시된 센서 네트워크에서 추정된 Euler angle과 kinematic chain model을 이용하여 추정된 serial link의 형상으로부터 내시경형상을 가시화 할 수 있음을 보여준다.