• 한국전문물리치료학회지
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• 제12권1호
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• pp.91-99
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• 2005

We assessed whether the use of a symmetrical upper limb motion trainer in daily repetitive training for a 6-week period reduced spasticity and improved motor function in three chronic hemiparetic patients. Upper limb motor impairment and disability were measured by the Fugl-Meyer Assessment (FMA), Modified Ashworth Scale (MAS) and Manual Muscle Test (MMT), respectively. The electromyography (EMG) of the affected hand was recorded during isometric wrist flexion and extension. In all patients, FMA and MMT scores were significantly improved after the 6-week training. However, MAS scores of the affected wrist spasticity did not change considerably. Onset and Offset delays in muscle contraction significantly decreased in the affected wrist. The co-contraction ratio of flexor and extensor muscles significantly increased after the 6-week training. Onset and offset delays of the muscle contraction and co-contraction ratio correlated significantly with the patients' FMA. This study showed that repetitive, symmetric movement training can improve upper limb motor functions and abilities in chronic hemiparetic patients. Also, the EMG assessment of motor response is likely to provide insights into mechanisms and treatment strategies for motor recovery in chronic hemiparetic patients.

• 로봇학회논문지
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• 제18권4호
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• pp.367-375
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• 2023

Most partial hand amputees experience limited wrist movement, which hinders the efficient functioning of upper limb, affecting hand-to-use coordination and the usability of the prosthetic hand. This limitation can lead to secondary musculoskeletal issues due to repetitive compensatory movement patterns. However, current partial hand prosthetic lack rotational wrist movement due to challenges in accommodating various hand shapes and limited space. In our study, we proposed a prosthetic hand with a wrist rotation module for partial hand amputees, aiming to reduce compensatory movement. To validate the proposed wrist rotation module, we conducted motion analysis during reach-to-grasp task. Furthermore, during the Jebsen-Taylor hand function test, we evaluated both the effect on upper limb movement and the usability of the prosthetic hand, comparing configurations with and without the wrist rotation module. The results showed that the prosthetic hand equipped with rotational wrist movements reduces compensatory movements and promotes efficient upper limb movement patterns. This finding highlights the value of incorporating a wrist rotation module in prosthetic hands to improve upper limb movement for partial hand amputees.

• 대한인간공학회지
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• 제33권6호
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• pp.565-575
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• 2014

Objective: The aim of this study is to evaluate the effect of weight of load and time on the physical workload of repetitive upper-limb tasks with handling light weight loads using EMG and perceived discomfort, and to investigate the relationship between EMG and perceived discomfort for those repetitive tasks of moving light weight loads. Background: Repetitive upper-limb motion is known as one of the main risk factors of musculoskeletal disorders, and a lot of repetitive tasks are carried out while handling light weight loads in the industry. In evaluating the workload of repetitive tasks handling light weight loads, EMG and perceived discomfort can be used, though their relationship in those work conditions are not much investigated. Method: A laboratory experiment with 18 healthy males were conducted to record EMG signals from 5 muscle sites of the right arm and shoulder and rate perceived discomforts for the body parts and the whole body while carrying out repetitive materials-handling tasks for 52min. The subjects were divided into 3 groups which handled the loads of 1kg, 2kg and 3kg, respectively. ANOVAs were conducted to analyze the effects of the weight and time on RMS of EMG amplitude (normalized RMS: NRMS), median frequency of power spectrum of EMG (normalized MDF: NMDF) and perceived discomfort. The correlations between NRMS and NMDF and perceived discomfort were also analyzed. Results: Statistically significant muscular fatigue effects were not found from NRMS and NMDF in most muscles, while there were significant increases of discomfort as the task time elapsed. It was shown that there were an increasing trend of the muscular activity as the weight of load increased and a decreasing trend of median frequency of EMG of upper and lower arms as time elapsed. It was found that there were significant negative correlations between NMDFs from the lower arm and discomfort ratings, though the relationships were weak. Conclusion: It can be concluded that the working conditions adopted in this study were not enough to induce muscular fatigue, while there was significant increase in perceived discomfort. A further study is necessary to integrate the objective and subjective measures for more reliable and sensitive evaluation of workload of repetitive tasks of handling light weight loads. Application: This study can be used as a basic study for the evaluation of workload of repetitive tasks handling light weight loads.

• International Journal of Advanced Culture Technology
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• 제7권1호
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• pp.231-236
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• 2019

Background/Objectives: This paper proposes a dual mode feedback-controlled cycling system for children with spastic cerebral palsy to rehabilitate upper extremities. Repetitive upper limb exercise in this therapy aims to both reduce and analyze the abnormal torque patterns of arm movements in three- dimensional space. Methods/Statistical analysis: We designed an exercycle robot which consists of a BLDC motor, a torque sensor, a bevel gear and bearings. Mechanical structures are customized for children of age between 7~13 years old and induces reaching and pulling task in a symmetric circulation. The shafts and external frames were designed and printed using 3D printer. While the child performs active/passive exercise, angular position, angular velocity, and relative torque of the pedal shaft are measured and displayed in real time. Findings: Experiment was designed to observe the features of a cerebral palsy child's exercise. Two children with bilateral spastic cerebral palsy participated in the experiment and conducted an active exercise at normal speed for 3 sets, 15 seconds for each. As the pedal reached 90 degrees and 270 degrees, the subject showed minimum torque, in which the child showed difficulty in the pulling task of the cycle. The passive exercise assisted the child to maintain a relatively constant torque while visually observing the movement patterns. Using two types of exercise enabled the child to overcome the abnormal torque measured in the active data by performing the passive exercise. Thus, this system has advantage not only in allowing the child to perform the difficult task, which may contribute in improving the muscle strength and endurance and reducing the spasticity but also provide customizable system according to the child's motion characteristic. Improvements/Applications: Further study is needed to observe how passive exercise influences the movement characteristics of an active motion and how customized experiment settings can optimize the effect of pediatric rehabilitation for spastic cerebral palsy.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.139-147
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• 2007

The aim of this study was to evaluate effects of short-tenn repetitive-bilateral excercise on the activation of motor network using functional magnetic resonance imaging (fMRI). The training program was performed at 1 hr/day, 5 days/week during 6 weeks. Fugl-Meyer Assessments (FMA) were performed every two weeks during the training. We compared cerebral and cerebellar cortical activations in two different tasks before and after the training program: (1) the only unaffected hand movement (Task 1); and (2) passive movements of affected hand by the active movement of unaffected hand (Task 2). fMRI was performed at 3T with wrist flexion-extension movement at 1 Hz during the motor tasks. All patients showed significant improvements of FMA scores in their paretic limbs after training. fMRI studies in Task 1 showed that cortical activations decreased in ipsilateral sensorimotor cortex but increased in contralateral sensorimotor cortex and ipsilateral cerebellum. Task 2 showed cortical reorganizations in bilateral sensorimotor cortex, premotor area, supplemetary motor area and cerebellum. Therefore, this study demonstrated that plastic changes of motor network occurred as a neural basis of the improvement subsequent to repetitive-bilateral excercise using the symmetrical upper-limb ann motion trainer.

• 재활복지공학회논문지
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• 제11권3호
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• pp.253-259
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• 2017

현재 뇌손상환자에게 시행되고 있는 재활치료들은 훈련 환경이 단조롭고 긴 시간 동안 단순하고 반복적인 운동으로 인해 흥미와 참여도가 떨어져 훈련 효율이 저하된다는 문제가 제기되었다. 이와 같은 문제를 해결하기 위해 본 논문에서는 상지 재활훈련을 위해 상지에서 측정되는 근전도 신호와 모션센서를 기반으로 하는 웨어러블 장치와 모바일 게임을 결합한 새로운 재활 프로그램 개발을 제안함으로 위에서 제기된 문제를 해결하고자 하였다. 개발된 웨어러블 장치는 밴드 형태로 제작되어 신체에 쉽게 착용 및 해체가 가능하고, 모바일 게임은 웨어러블 장치로부터 측정되는 근전도 신호를 통하여 인식되는 움켜잡는 행동(grasp motion)과 모션센서를 통하여 인식되는 굴곡(flexion), 신전(extension), 외전(abduction), 내전(adduction)을 반영하여 게임을 통한 재활훈련이 가능하도록 설계되었으며, 난이도 조절을 통한 환자 개개인에 적합한 맞춤형 재활환경을 제공할 수 있도록 하였다. 개발된 프로그램을 상지 재활이 필요한 14명의 뇌손상 환자를 대상으로 적용한 후, 설문조사를 통한 유용성 평가를 진행한 결과 개발된 재활프로그램이 기존 재활프로그램보다 흥미가 있었고 재활훈련 간 지루하지 않았다고 응답하였고, 추후 개발된 프로그램 재사용에 대한 의지를 보였다.

• 대한인간공학회지
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• 제36권5호
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• pp.589-599
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• 2017

Objective: The objective of this study was to measure the upper-limb motions and postures of grapes-harvesting tasks using electrical goniometers and analyze the upper-limb motions in a kinematic way to assess the risk of musculoskeletal disorders. Background: Grapes farmers are exposed to various risk factors of musculoskeletal disorders (MSDs) such as repetitive upper-limb motions, non-neutral postures, and manual handling of heavy items. The farmers have to use scissors repetitively while harvesting grapes with their being arms elevated over the shoulder height, which presumed to increase the physical workload. It has been reported that the grapes farmers feel the harvesting task as the one of the hardest work in cultivating grapes. We tried measure the wrist and elbow angles while the farmers were carrying out harvesting tasks to understand how much workload the work impose on the farmers, which can be helpful in making interventions of preventing musculosksletal disorders among grapes farmers. Method: We measured joint angles at the right wrist and elbow with a wireless measuring system with two electrical goniometers from five grape farmers. The grapes-harvesting task was classified into 6 different subtasks: 1) searching, 2) picking, 3) cleaning, 4) carrying, 6) storing, and 7) miscellaneous tasks. The subtasks were compared by mean angles, 10%, 50%, and 90% APDF values of wrist flexion/extension, ulnar/radial deviation, and elbow flexion. Results: The Kruskal-Wallis tests showed that the 10th percentiles of APDF of ulnar/radial deviation and flexion/extension of the wrist significantly differs among subtasks (p<0.05). It was found that the farmers assumed more deviated wrist postures in the ulnar direction when they picking and adjusting the grapes. The use of scissors seemed to force the farmers to severely bend their wrist in the directions of ulnar deviation and flexion. The grapes-harvesting task showed similar wrist postures and motion with poultry deboning and milking tasks. Conclusion: The grapes harvesting tasks make the farmers take ulnar deviated and extended postures in the wrist. The use of scissors makes them take more severely deviated postures in the wrist. Safety guidelines including use of ergonomic scissors can be provided to the farmers to improve their work conditions. Application: The results of this study can be used as a basic data for the development of safety guidelines for agricultural work.