• 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.

• Clinics in Shoulder and Elbow
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• 제8권2호
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• pp.81-87
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• 2005

Epicondylitis, as a tendinopathy characterized by fibroblast and microvascular hyperplasia, is a common musculoskeletal problem especially related with repetitive hand and wrist motion. It has a prevalence of between 0.2% and 5% in general population depending on the amount of exposure to manual labor jobs. Although it is known that the pathological lesions lie in the flexor or extensor common tendons, there could be collateral ligament lesions and/or reactive synovitis accompanied, which may make a case unresponsive to the treatment aimed only at the tendinopathy. Epicondylitis is easy to diagnose with typical pain, tenderness, and positive provocation tests. However, many conditions can mimic epicondylitis that further imaging or electrodiagnostic studies should be undertaken to exclude other possible problems. Ultrasonography provides information about the existence and extent of tendinopathy with relatively high specificity. Magnetic resonance imaging is often required to rule out other problems and confirm the diagnosis of the cases intractable to long term treatment. Many options of treatment are available for epicondylitis while numerous conflicting evidences have been noted, debating one treatment method is better than the others. Since it was reported that over 80% of epicondylitis improved within a year no matter what was done as treatment, it is a challenge to make accurate diagnosis and combine effective therapeutic regimens for the 20% of intractable cases.

• 한국운동역학회지
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• 제23권1호
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• pp.1-9
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• 2013

The purpose of this study was to provide information on athletes' characteristics and advantages and disadvantages by analyzing the kinematic factors having a decisive influence on competitive abilities such as release conditions in the delivery phase on major Korean javelin athletes. Two supported javelin throwers of the Korean national team participated in this study. The total average time required of the delivery phase was 0.31(${\pm}0.016$). The athletes' release angle was 33.2 to 41.7 degrees. The attack angle varied widely from -3.5 to 5.9 degrees. The Javelin heights of Subject A and B were 95.9 and 89.2%Ht. The average stride length were 180.6 and 176.7cm. The center of mass velocity of LFD and REL was relatively low in all the subjects. The average deceleration rates of center of mass velocity of Subject A and B were 57.2 and 48.9%lose. The left knee angles of Subject A and B were 160.1 and 155.5 degrees in LFD, 153.0 and 164.0 degrees in REL. The joint velocity of upper limb segments was relatively low in all the subjects. The maximum average wrist velocity of Subject A and B was 18.2 and 16.3 m/s in REL.

• 한국안전학회지
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• 제20권4호
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• pp.148-153
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• 2005

Computer dominated jobs and industrial automation have rapidly created work-related musculoskeletal disorders(WMSDs) and WMSDS are expanding to employee of other general industry. Specific risk factors associated with WMSDs include repetitive motion, heavy lifting, forceful exertion, contact stress, vibration awkward posture and rapid hand and wrist movement. The purpose of this paper is to analyze the effects of the neck muscle workload according to posture(joint angle) and load weight. Seven male students participated in this study. To analyze neck muscle workload was studied on electromyographic(EMG) activity for sternocleidomastoid and trapezius, was subjectively rated using a Borg's CR-10 scale. ANOVA showed that the CR-10 ratings and most EMG root-mean-square (RMS) value were statistically significant improvement according to posture(joint angle) and load weight. The results of this study indicate the joint angle and weight of neck muscle workload to provide safe working conditions. To reduce the large number and severity of WMSDs employees have been experiencing, we need to redesign the job in workplace to identify and control hazards that are reasonably likely to be causing or contributing to the WMSDs.

• Clinics in Shoulder and Elbow
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• 제21권4호
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• pp.252-255
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• 2018

A 51-year-old male who is right-handed visited the outpatient for right fingers-drop. The patient's fingers, including thumb, were not extended on metacarpophalangeal joint. The active motion of the right wrist was available. The electromyography and nerve conduction velocity study were consistent with the posterior interosseous neuropathy. Further evaluation was done with the magnetic resonance imaging for finding the space-occupying lesion or any possible soft tissue lesion around the radial nerve pathway. On magnetic resonance imaging, the ganglion cyst, which was about 1.8 cm in diameter, was observed on the proximal part of the superficial layer of the supinator muscle (Arcade of Frohse). The surgical excision was done on the base of ganglion cyst at the base of stalk of cyst which looked to be connected with proximal radioulnar joint capsule. The palsy had completely resolved when the patient was observed on the outpatient department a month after the operation.

• 로봇학회논문지
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• 제14권3호
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• pp.228-235
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• 2019

This paper presents a multiple DoFs (degrees-of-freedom) prosthetic forearm and sEMG (surface electromyogram) pattern recognition and motion intent classification of forearm amputee. The developed prosthetic forearm has 9 DoFs hand and single-DoF wrist, and the socket is designed considering wearability. In addition, the pattern recognition based on sEMG is proposed for prosthetic control. Several experiments were conducted to substantiate the performance of the prosthetic forearm. First, the developed prosthetic forearm could perform various motions required for activity of daily living of forearm amputee. It was able to control according to shape and size of the object. Additionally, the amputee was able to perform 'tying up shoe' using the prosthetic forearm. Secondly, pattern recognition and classification experiments using the sEMG signals were performed to find out whether it could classify the motions according to the user's intents. For this purpose, sEMG signals were applied to the multilayer perceptron (MLP) for training and testing. As a result, overall classification accuracy arrived at 99.6% for all participants, and all the postures showed more than 97% accuracy.

• 한국운동역학회지
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• 제31권3호
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• pp.199-204
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• 2021

Objective: The purpose of this study was to present a new idea of methodology to evaluate Poomsae performance using inertial measurement unit (IMU) sensors in terms of signal processing techniques. Method: Ten collegian Taekwondo athletes, consisting of five Poomsae elite athletes (age: 21.4 ± 0.9 years, height: 168.4 ± 11.3 cm, weight: 65.0 ± 10.6 kg, experience: 12 ± 0.7 years) and five breaking demonstration athletes (age: 21.0 ± 0.0 years, height: 168.4 ± 4.7 cm, weight: 63.8 ± 8.2 kg, experience: 13.0 ± 2.1 years), voluntarily participated in this study. They performed three different black belt Poomsae such as Goryeo, Geumgang, and Taebaek Poomsae repeatedly twice. Repeated measured motion data on the wrist and ankle were calculated by the methods of cosine similarity and Euclidean distance. Results: The Poomsse athletes showed superior performance in terms of temporal consistency at Goryeo and Taebaek Poomsae, cosine similarity at Geumgang and Taebaek Poomsae, and Euclidian distance at Geumgang Poomsae. Conclusion: IMU sensor would be a useful tool for monitoring and evaluating within-subject temporal variability of Taekwondo Poomsae motions. As well it distinguished spatiotemporal characteristics among three different Poomsae.

• 대한임베디드공학회논문지
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• 제17권1호
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• pp.1-7
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• 2022

The number of patients with many complications grows with the increase of aging population. As the elders and severely ill patients spend most of their time in bed, it leads to Pressure Injuries (PI) such as bedsores. Unfortunately, there is no method to automatically detect changes in patient's posture which leads to the need for a caregiver every set of times when the patient needs to be moved. Many studies are conducted to solve this inefficient problem. Yet, these studies require costly devices or use methods that disturb patient's sleeping environment. Those methods are mostly hard to implement in practice due to these reasons. We propose a method to detect posture using a three-axis acceleration sensor from the wrist band. We developed a wearable watch that measures sleep-related data. We analyzed 40 people's sleep data with a wearable module and watch to measure their postures such as supine, left-side, and right-side. Then, we compared the classified posture from the watch with the wearable module and achieved 90% accuracy. Therefore, we concluded that only by using the wearable watch, we can detect the sleeping position without any new equipment or system to diagnose the patients without discomfort during their daily lives.

• Clinical Pain
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• 제18권2호
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• pp.107-110
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• 2019

Flexor carpi radialis (FCR) muscle is located in the forearm anteriorly that runs through a synovial fibro-osseous tunnel in the forearm. We described a case of FCR tendon rupture due to repetitive overuse injury. A 55-year-old man, right-hand dominant, presented with right forearm pain and swelling which started 3 days ago while playing amateur golf. Focal tenderness and bruising over volo-ulnar region of the right forearm were examined. Plain radiographs showed soft tissue edema around lesion area and no detectable fracture. Ultrasonography showed multiple hypoechoic lesions suspected as hematoma of the flexor muscle group. After done magnetic resonance imaging, he was diagnosed with rupture of FCR tendon at proximal origin and strain of flexor digitorum superficialis and palmaris longus muscle. He received compressive dressing and restriction of wrist range of motion for three weeks. Two months later, remaining traces of lesions were observed at the follow-up ultrasonography and the pain disappeared.

• 대한안전경영과학회지
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• 제26권2호
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• pp.87-92
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• 2024

This study aims to compare six observational methods for assessing arm- and hand-intensive tasks, based on literature review. The comparison was conducted in viewpoints of body regions, force/external load, motion repetition, other factors including static posture, coupling, duration/break, pace, temperature, precision task, and final risk or exposure level. The number of risk factors assessed was more, and assessment procedure was more complex than the observational methods for assessing whole-body postural loads such as Ovako Working Posture Analysis System(OWAS), Rapid Upper Limb Assessment(RULA), and Rapid Entire Body Assessment(REBA). Due to these, the intra- and inter-reliabilities were not high. A past study showed that while Hand Arm Risk Assessment Method(HARM) identified the smallest proportion of the work tasks as high risk, Strain Index(SI) and Quick Exposure Check(QEC) hand/wrist were the most rigorous with classifying most work tasks as high risk. This study showed that depending on the observational technique compared, the evaluation factors, risk or exposure level, and evaluation results were different, making it necessary to select a technique appropriate for the characteristics of the work being assessed.