• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.72-78
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• 2010

Purpose: Too develop a flexible drill device that can be inserted into the shoulder joint so that arthroscopic transosseous suture repair for Bankart lesion is possible. Materials and Methods: We created a device composed of a flexible drill unit and a guide pipe unit. The flexible drill unit was made of flexible multifilament wires (1.2 mm in diameter) that was twisted into one cord so that it can flex in any direction and a drill bit (1.2 mm in diameter) that is attached onto one end of the flexible wire. The guide pipe unit was a 150 mm long metal pipe (2.0 mm in inner diameter and 3.0 mm in outer diameter), with one end bent to 30 degrees. The flexible drill set was inserted into the shoulder joint through the posterior portal of the joint. The guide pipe component was placed onto the medial wall of the glenoid so that the pipe was placed 5 mm posterior to the margin of the anterior glenoid rim. The flexible drill was driven through the glenoid by the power drill so that holes were made in the glenoid. A non- absorbable suture was passed through the hole. Tying of a sliding knot tying was accomplished over the capsule and labrum after making a stitch through the capsule and labrum with a suture hook loaded with suture passer. The same procedures were done at the 2 and 4 O'Clock positions of the glenoid. Results: Five cases with Bankart lesion received arthroscopic transosseous repair with our flexible drill device. There were no intraoperative problems. Neither redislocation nor subluxation was reported at final follow-up. Conclusion: Arthroscopic transosseous suture repair without suture anchors and easy tying of a sliding knot are possible with a flexible drill set.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.5
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• pp.299-307
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• 2003

The local structure of CMAC neural networks (NN) results in better and faster controllers for nonlinear dynamical systems. In this paper, we propose a CMAC NN-based disturbance observer and its corresponding controller for a flexible joint robot. The CMAC NN-based disturbance observer compensates for the parametric uncertainties and the external disturbances throughout the entire mechanical system. Finally, a simulation result is given to demonstrate the effectiveness of proposed design method's robust tracking performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.643-650
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• 2017

The control of flexible joint robot is getting more attentions because its applications are more frequently used for robot systems in these days. This paper proposes a robust impedance controller for the flexible joint robot by using integral sliding mode control and backstepping control. The sliding mode control decouple disturbances completely but requires matching condition for disturbances. The dynamic model of flexible joint robot is divided into motor side and link side and the disturbance of the link side does not satisfy matching condition and cannot be decoupled directly by the actual input in the motor side. To overcome this difficulty, backstepping control technique is used with sliding mode control. The mismatched disturbance in the link side is changed into matched one in the respect to virtual control input which is the state controlled by actual input in the motor side. Integral sliding mode control is used to preserve the impedance control performance and the improved robustness at the same time.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.509-515
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• 2020

The purpose of this study was to analyze the correlation between passive ankle movement range and knee joint kinetic variables during squat movement. In this study, a total of 27 subjects participated in this study, 19 men and 8 women, who had no history of the musculoskeletal system of the lower extremity. To verify the correlation between the ankle joint flexibility and the knee joint kinetic variables during deep squat, it was performed pearson's correlation coefficient and variables showing statistically significant correlation were performed by simple regression analysis at a significant level of α .05. Through this study, the relationship between the peak joint moment and joint reaction force factors that determine ankle joint flexibility and knee joint pressure was confirmed. Therefore, when applying an exercise that can generate a lot of load on the knee joint such as deep squats during strength training, checking the degree of flexibility of the ankle joint among physical characteristics to the individual may reduce the stability of the body and the risk of injury to the knee joint. It is expected to be helpful in setting the intensity of exercise that can be done.

• Journal of the Korean Society of Physical Medicine
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• v.3 no.1
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• pp.57-62
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• 2008

목적 : 이 연구의 목적은 수동신장과 능동신장이 단축된 슬괵근에 대한 유연성 회복에 미치는 영향을 알아보는데 있다. 방법 : 90-90 하지직거상 검사를 통해 슬괵근의 단축이 있는 것으로 판명된 자발적 참여자를 대상으로 정적인 자세유지를 적용한 수동신장과 대퇴사두근의 근력강화 운동을 이용한 능동신장을 적용하여 슬관절의 관절운동 범위의 변화를 측정하였다. 측정은 90-90 하지직거상 검사를 이용하여 신장 전, 후, 신장 후 60분이 경과한 뒤에 각각 측정하였다. 결과 : 두 그룹 모두 신장 전, 후, 신장 후 60분이 경과한 이후의 슬관절의 관절운동범위에 유의한 향상이 있었으나, 두 그룹 간에는 유의한 차이가 없었다. 결론 : 수동신장과 능동신장은 모두 단축된 슬괵근의 유연성 회복에 유용하게 적용될 수 있으며, 단기간의 신장 적용 후 슬괵근의 유연성 유지에도 효과적인 중재이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.3
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• pp.236-242
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• 2009

When two-link flexible arm is rotated about an joint axis, transverse vibration may occur. In this paper, vibration dynamics of flexible robot arm is modeled by using Bernoulli-Euler beam theory and Lagrange equation. Using the fact that matrix $\dot{D}$-2C is skew symmetric, new controllers which have a simplified structure with less computational burden is proposed. Lyapunov stability theory is applied to achieve a stable deterministic nonlinear controller for the regulation of joint angle.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2005.03a
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• pp.79-79
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• 2005

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.4
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• pp.1-12
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• 2004

This paper presents an adaptive fuzzy backstepping (AFB) controller for a single-link flexible joint robot in the Presence of Parametric uncertainties and external disturbances. Adaptive fuzzy logic systems are used as universal approximators to counteract the model uncertainties coming from robot dynamics and to compensate for the nonlinearities coming from adaptive backstepping method. The approach suggested herein does not require neither an additional supervisory nor a robustifying controller and guarantees that tracking error is uniformly ultimately bounded (UUB) within a sufficiently small residual set. Finally, a simulation result is given to demonstrate the robust tracking performance of proposed design method.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.839-847
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• 2020

The purpose of this study was to analyze the effects of ankle flexibility, gender, and Q-angle on the ankle joint injury factors during one leg drop landing. For this study, 16 males(age: 20.19±1.78 years, mass: 69.54±10.12 kg, height: 173.22±4.43 cm) and 16 females(age: 21.05±1.53 years, mass: 61.75±6.97 kg, height: 159.34±4.56 cm) in their 20's majoring in physical education using the right foot as their dominant feet were selected as subjects. First, an independent t-test of joint motion and joint moment according to the experience of ankle injury was conducted to determine the effect of physical characteristics on ankle joint injury during one leg drop landing(α = .05). Second, the variable that showed a significant difference through t-test was set as the dependent variable, and the ankle flexibility, gender difference, and Q-angle were designated as independent variables to use Multiple Linear Regression(α =. 05). As a result of this study, it was found that the group that experienced an ankle joint injury was found to use a landing strategy and technique through adduction of the ankle joint and internal rotation of the knee joint, unlike the group without an injury. It was also confirmed that this movement increases the extension moment of the ankle joint and decreases the extension moment of the hip joint. In particular, it was found that the dorsi flexion flexibility of the ankle affects the ankle and knee landing strategy, and the gender difference affects the ankle extension moment. Therefore, it was confirmed that physical characteristics factors affecting ankle joint injuries during one leg drop landing.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.278-286
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• 2009

The aims of this study were to determined whether excitability of the $\alpha$-motor neuron is modulated by stretching and this changes were associated with flexibility of the muscle. In this study, $\alpha$-motor neuron excitability was measured by using the Hmax/Mmax ratio of the gastrocnemius H-reflex, and muscle flexibility was measured with the range of motion of the ankle dorsiflexion. The gastrocnemii of 10 healthy volunteers were stretched for 4 minutes(2 minutes stretching, 1 minute rest, and 2 minutes stretching) in each session by manual force. The Hmax/Mmax ratio of the H-reflex, as well as the range of motion of the ankle dosiflexion was measured through four different conditions: before stretching, as soon as after $1^{st}$ stretching, as soon as after $2^{nd}$ stretching and at 48 hours after $2^{nd}$ stretching. Excitability of the $\alpha$-motor neuron was decreased significantly after $1^{st}$ and $2^{nd}$ stretching(p<0.05). Furthermore, the range of the dorsiflexion was increased significantly after $1^{st}$ and $2^{nd}$ stretching(p<0.05). However, the excitability of the $\alpha$-motor neuron and range of the dorsiflexion at 48 hours after $2^{nd}$ stretching were not different from those of before stretching. These results suggest that reduced $\alpha$-motor neuron excitability of the gastrocnemius and increased flexibility of the ankle dorsiflexion would be followed by activation of the type III mechanoreceptor which around the ankle joint and the Golgi tendon organ in the gastrocnemius.