• Journal of the Korean Society of Physical Medicine
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• v.14 no.1
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• pp.53-61
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• 2019

PURPOSE: This study examined the dynamic range of motion (ROM) of the hip, knee, and ankle joint when wearing different shoe sole lifts, as well as the limb asymmetry of the range according to the leg length discrepancy (LLD) during normal speed walking. METHODS: The participants were 40 healthy adults. A motion analysis system was used to collect kinematic ROM data. The participants had 40 markers attached to their lower extremities and were asked to walk on a 6 m walkway, under three different shoe lift conditions (without an insole, 1 cm insole, and 2 cm insole). Visual3D professional software was used to coordinate kinematic ROM data. RESULTS: Most of the ROM variables of the short limbs were similar under each insole lift condition (p>.05). In contrast, when wearing a shoe with a 2 cm insole lift, the long limbs showed significant increases in flexion and extension of the knee joint as well as; plantarflexion, dorsiflexion, pronation, eversion, and inversion of the ankle joint (p<.05). Of the shoes with the insole lifts, significant differences in all ROM variables were observed between the left and right knees, except for the knee internal rotation (p<.05). CONCLUSION: As the insole lift was increased, more ROM differences were observed between the left and right limbs, and the asymmetry of the bilateral lower limbs increased. Therefore, appropriate interventions for LLD are needed because an artificial mild LLD of less than 2.0 cm could lead to a range of musculoskeletal problems of the lower extremities, such as knee and ankle osteoarthritis.

• The Journal of Korea Robotics Society
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• v.1 no.2
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• pp.203-211
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• 2006

In this research, a comprehensive study is performed upon the design of a quadruped walking robot. In advance, the walking posture and skeletal configuration of the vertebrate are analyzed to understand quadrupedal locomotion, and the roles of limbs during walking are investigated. From these, it is known that the forelimbs just play the role of supporting their body and help vault forward, while most of the propulsive force is generated by hind limbs. In addition, with the study of the stances on walking and energy efficiency, design criteria and control method for a quadruped walking robot are derived. The proposed controller, though it is simple, provides a useful framework for controlling a quadruped walking robot. In particular, introduciton of a new rhythmic pattern generator relieves the heavy computational burden because it does not need any computation on kinematics. Finally, the proposed method is validated via dynamic simulations and implementing in a quadruped walking robot, called AiDIN(Artificial Digitigrade for Natural Environment).

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.919-926
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• 2010

This paper proposes a wearable hand rehabilitation device, DULEX, for persons with functional paralysis of upper-limbs after stoke. DULEX has three degrees of freedom for rehabilitation exercises for wrist and fingers except the thumb. The main function of DULEX is to extend the range of motions of finger and wrist being contracture. DULEX is designed by using a parallel mechanism, and its parameters such as length and location of links are determined by kinematic analysis. The motion trajectory of the designed DULEX is aligned to human hand to prevent a slip. To reduce total weight of DULEX, artificial air muscles are used for actuating each joint motion. In feedback control, each joint angle is indirectly estimated from the relations of the input air pressure and the output muscle length. Experimental results show that DULEX is feasible in hand rehabilitation for stroke survivals.

• Journal of Biomedical Engineering Research
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• v.26 no.4
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• pp.243-249
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• 2005

The number of people who have lost limbs due to amputation has increased due to various accidents and diseases. Numerous attempts have been made to provide these people with prosthetic devices. These devices are often controlled using myoelectric signals. Although the success of fitting myoelectric signals (EMG) for single device control is apparent, extension of this control to more than one device has been difficult. The lack of success can be attributed to inadequate multifunctional control strategies. Therefore, the objective of this study was to develop multifunctional myoelectric control strategies that can generate a number of output control signals. We demonstrated the feasibility of a neural network classification control method that could generate 12 functions using three EMG channels. The results of evaluating this control strategy suggested that the neural network pattern classification method could be a potential control method to support reliability and convenience in operation. In order to make this artificial neural network control technique a successful control scheme for each amputee who may have different conditions, more investigation of a careful selection of the number of EMG channels, pre-determined contractile motions, and feature values that are estimated from the EMG signals is needed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.843-850
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• 2017

The EMG amplitude estimator, which has been investigated as an indicator of muscle force, is utilized as the control input to artificial prosthetic limbs. This paper describes an application of the optimal EMG amplitude estimator to the surface EMG signals recorded during constant isometric %MVC (maximum voluntary contraction) for 30 seconds and reports on assessing performance of the amplitude estimator from the application. Surface EMG signals, a total of 198 signals, were recorded from biceps brachii muscle over the range of 20-80%MVC isometric contraction. To examine the estimator performance, a SNR(signal-to-noise ratio) was computed from each amplitude estimate. The results of the study indicate that ARV(average rectified value) and RMS(root mean square) amplitude estimation with forth order whitening filter and 250[ms] moving average window length are optimal and showed the mean SNR improvement of about 50%, 40% and 20% for each 20%MVC, 50%MVC and 80%MVC surface EMG signals, respectively.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2962-2964
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• 2005

Magneto-Rheological (MR) fluid is suspension of fine magnetic particles in a liquid carrier such as silicon oil or water. MR fluid exhibits solid-like mechanical behavior into chain or clusters with high yield stress when magnetic field is applied to the particles. The response of MR fluids is very quick and reversible after removal of the field. MR Fluids have high yield stress (up to 5kPs) and operate in low voltage power supply. Recently, MR damper using MR fluids was open used in vibration control system such as structural devices, seat vibration controllers and helicopter rotor systems, but it is too big in size and heavy. Therefore, it is not appreciate to rehabilitation devices such as prosthetic limbs.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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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.

• Journal of Korean Physical Therapy Science
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• v.7 no.1
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• pp.367-375
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• 2000

The purpose of this study is to announce the present condition, walking training, and adaptable training of a limb amputated patient. The study is a successful report of the limb amputated patient through the medical treatment of the physical therapy. A cause of the limb amputated patient, a truck driver, was that the patient was hit by a train when the driver alight from the truck. Then, the driver was surgical operated on left AK (Above Knee) amputation and left AE (Above Elbow) amputation by orthopedics at the Young Dong Severance Hospital on Dec.7, 1996. Two weeks after the operation (Dec., 22, 1996), the patient was trained at the Yonsei Medical Center Physical Therapy Hospital for the walking and temper adjust training. It was possible to do a flat surface walking and a slope surface walking without helping due to the patients optimistic personal character and motivation. However, the patient struggled to a dull surface walking and his weak endurance. the patient has several problems when the patient wears artificial legs and hands, fears on fall down, and mentally worries on noise when he walks. It is necessary to approach for this problems by many fields of the helpers, such as Rehabilitation medical doctor, physical therapist, occupational therpist, artificial limbs makers, psychologists, and etc. Therefore, in order for recovering from the amputated parts function after the surgical operation, more approved reports have to be for the amputated patients due to increasing traffic accidents, industrial disaster, cancer, diabetes, obstacles of the peripheral nervous system, and etc.

• Korean Journal of Computational Design and Engineering
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• v.16 no.6
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• pp.391-396
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• 2011

Gait is walking attitude and indicating state. The body's gait is a good mix in the center of body mechanics and exercises to wake up gently at the same time switch is a pass which is complicated at legs various joints. The shifting action what swing phase and stance phase rhythmic movement of body. One from piece moves with different dot. Especially plain walking and stair walking as a vehicle has been used frequently. Characteristics of the stair walking while the balanced the horizontal and vertical movement. Stair walking often takes place in everyday. It requires large range more than walking at plain in the moment and joint range of gait motion. And consistently applied to joints and various types of loads at legs joint may involve joint disorders. In this study, spastic cerebral palsy existing artificial limbs for disabled people when developing calibration equinus deformity patients induce muscle pain when walking on stairs independently, to reduce the research. Comparing the characteristics of the walking up the stairs for analysis patellofemoral joint pain as a result it is to provide engineering data.

• ETRI Journal
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• v.40 no.4
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• pp.511-521
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• 2018

The ability to realize human-motion imitation using robots is closely related to developments in the field of artificial intelligence. However, it is not easy to imitate human motions entirely owing to the physical differences between the human body and robots. In this paper, we propose a work chain-based inverse kinematics to enable a robot to imitate the human motion of upper limbs in real time. Two work chains are built on each arm to ensure that there is motion similarity, such as the end effector trajectory and the joint-angle configuration. In addition, a two-phase filter is used to remove the interference and noise, together with a self-collision avoidance scheme to maintain the stability of the robot during the imitation. Experimental results verify the effectiveness of our solution on the humanoid robot Nao-H25 in terms of accuracy and real-time performance.