• 대한통합의학회지
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• 제4권4호
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• pp.83-90
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• 2016

Purpose : Recommended posture according to the location of operating teeth have been standardized in dental clinic to prevent musculoskeletal disorder. However, clinicians do not comply with this rule in many cases. This study investigated the effects of operating posture on cranio-cervical range of motion (CROM) and muscles activity of neck and upper extremity. Methods : Sixteen healthy dental hygiene students were participated. During operating posture (3 recommended and 3 experimental postures which were set front, side, back, respectively), CROM in the fronal and sagittal plane were measured by Cervical Range of Motion Instrument and muscle activities of Sternocleidomastoid, upper trapezius, middle deltoid, extensor carpi radialis, brachioradialis, and abductor pollicis brevis were measured by Pocket EMG system. Result : CROM were significantly decreased in recommended posture in comparison with experimental posture (p<.05). In addition, muscle activity of middle deltoid was significantly decreased in recommended front posture. Moreover, brachioradialis and extensor carpi radialis showed the same result in recommended back posture (p<.05). Conclusion : Recommended posture is close to neutral posture and to reduce muscle fatigue and overuse, which may considered as a preventing musculoskeletal disorder and partially explain its efficacy in dental clinic.

• 대한임상검사과학회지
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• 제44권4호
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• pp.184-198
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• 2012

The purpose of intra-operative neurological monitoring (INM) is to minimize surgically induced nerve damage, sensory nerves and motor neurons without affecting the operations to proceed during surgery such as evoked potentials (EP), electromyography (EMG), electroencephalography (EEG), transcranial doppler (TCD), etc. During the course of checking a patient's condition, surveillance of ambulatory patients is a very different thing to check if the test is done under general anesthesia. INM can be possible or impossible depending on the type of drugs used and their concentrations because the monitoring is performed under anesthesia. Therefore, it is emphasized on the necessity of reviewing anesthesia which influences on INM.

• PNF and Movement
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• 제18권2호
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• pp.223-231
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• 2020

Purpose: The purpose of the study was to compare the effects of different methods of pelvic control on abdominal muscle activity and lumbopelvic rotation angle during active straight leg raising (ASLR) in patients with chronic back pain. Methods: The study participants were patients with low back pain (n = 30). They were instructed to perform ASLR with pelvic control, ASLR with pelvic belt, and ASLR only. Surface electromyography data were collected from the ipsilateral rectus femoris (IRF), ipsilateral internal oblique (IIO), contralateral external oblique (CEO), and ipsilateral rectus abdominal (IRA) muscles, and lumbopelvic rotation angle was measured using a motion analysis device. Results: Activation of all abdominal muscles was greater in the ASLR with pelvic control group than in the ASLR with pelvic belt and ASLR groups. The lumbopelvic rotation angle was lower in the ASLR with pelvic control group than in the other two groups (p < 0.05). Conclusion: These results suggest that ALSR with pelvic control is an effective means of increasing abdominal muscle activity and reducing unwanted lumbopelvic rotation in patients with chronic low back pain. Controlling the pelvis using the opposite leg is an effective form of ASLR exercise for patients with chronic low back pain.

• 정보과학회 논문지
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• 제42권12호
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• pp.1544-1550
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• 2015

최근 웨어러블 로봇에 활용이 가능한 실용적인 웨어러블 로봇 인터페이스 개발이 활발하게 이루어지고 있다. 본 논문은 인간의 생체신호 중 근전도를 활용하여, 회귀 기법 기반 연속적인 손목 움직임 의도 추정 방법을 제안한다. 실생활에서 사용자의 상지 자세 변화는 근전도 신호를 변조시켜 성능 저하의 주요한 원인이 되는데, 이를 해결하기 위해 서로 다른 상지 자세에서 학습된 회귀 기법 기반 움직임 추정모델을 통합함으로써 상지 자세 변화에도 강인한 연속적인 손목 움직임 의도 추정 방법을 제안한다. 실험결과에서 서로 다른 상지 자세에서 손목 움직임 의도를 추정하였을 때 제안 방법의 성능이 기존 방법보다 우수함을 확인하였다.

• 한국전문물리치료학회지
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• 제14권2호
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• pp.68-75
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• 2007

Reductions in strength and range of motion in older persons have been associated with decreased functional mobility and risk of falls. The purpose of this research was to investigate the effect of intensive dynamic balance exercise (DBE) during 8 weeks on onset time of medial gastrocnemius and tibialis anterior muscle contraction after perturbation in older women. Thirty subjects were randomly assigned into DBE group or control group. The DBE group participated in 50 minutes 3 days a week for 8 weeks. Surface electromyography (EMG) activity was recorded from the medial gastrocnemius and tibialis anterior muscles of left side. Outcome data were collected both groups at the pre-exercise and post-exercise. Independent t-test and paired t-test were used to determine the statistical difference. Results showed that the passive range of motion and functional reach test were significantly increased in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles and discrepancy of onset time significantly reduced in the DBE group than the control group at the post-exercise (p<.05). The onset time of both muscles were significantly reduced in the post-exercise than the pre-exercise in the DBE group (p<.05). The discrepancy of onset time in the DBE group was significantly reduced in the post-exercise than the pre-exercise (p<.05). These findings suggest that intensive dynamic balance exercise for the eight weeks was effective in improving the postural control with older persons.

• 한국정보전자통신기술학회논문지
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• 제8권1호
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• pp.65-69
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• 2015

작업치료에서 관절의 가동성은 치료 절차와 기간에 영향을 미치는 중요한 요소이다. 수동적 스트레칭과 능동적 스트레칭을 병행하는 고유수용성 신경근 촉진법이 고관절의 가동성에 미치는 영향과 주요 굽힘/폄근의 근전도 활성정도 바탕으로 고유수용성 신경근 촉진 스트레칭의 생체역학적 특징을 고찰하였다. 10명의 20대 학생을 대상으로 고유수용성 신경근 촉진 스트레칭을 실시한 결과 고관절의 가동성이 전담 보조자의 도움을 받았을 때, 평균 $18.9^{\circ}$ 증가하였고 넙다리네갈래근과 뒤넙다리근의 근전도의 활성 또한 고유수용기의 생체역학적 특징을 나타내었다.

• 대한인간공학회지
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• 제27권3호
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• pp.15-22
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• 2008

The purpose of this study was to define the effects of noise and background music on the trunk muscle fatigue during dynamic lifting and lowering tasks. Six healthy male subjects with no prior history of low back disorders participated in this study. The participants were exposed to two levels of background noise such as 40dB noise and 90dB noise and three levels of background music such as no music, slow music, and fast music. Six different combinations of background noise and background music were played while the participants were performing the lifting task at 15% level of Maximum Voluntary Contraction. Electromyography signals from six muscles were collected and fatigue levels were analyzed quantitatively. In results, the 90dB noise increased trunk muscle fatigue and slowed down the recovery. The trunk muscle fatigue was the lowest when the fast music was played for as background. After recovery, the 90dB noise increased trunk muscle fatigue. The trunk muscle fatigue was the lowest when the slow music was played for as background. The results can be useful to manage the cumulative fatigue of trunk muscles due to background noise and music during repetitive lifting and lowering tasks in industry.

• 대한인간공학회지
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• 제27권3호
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• pp.33-41
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• 2008

The goal of this study was to compare wrist posture, muscular loads and perceived comfort among wearable wrist rest (WR), general wrist rest(GR), no wrist rest(NR) during keyboard and mouse use. Thirteen subjects performed text editing task in three test conditions: wearable wrist rest(WR), general wrist rest(GR), no wrist rest(NR). During text editing task, the right wrist posture was recorded by an electrogoniometer and the muscle activity in upper trapezius, anterior deltoid, extensor digitorum, extensor carpi ulnaris were recorded by electromyography. After all of the tests, the subjects rated perceived comfort. Working with wearable wrist rest(WR), compared to no wrist rest(NR) and general wrist rest(GR), decreased wrist radial/ulnar deviation and also decreased muscle activity in upper trapezius and anterior deltoid. At the same time, in work with wearable wrist rest(WR), the subjects rated more comfort at 5 of 8 body locations(shoulder, upper arm, wrist, hand, body).

• 제어로봇시스템학회논문지
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• 제21권11호
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• pp.1034-1037
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• 2015

In recent years in the field of robotics, various methods have been developed to create an intimate relationship between people and robots. These methods include speech, vision, and biometrics recognition as well as gesture-based interaction. These recognition technologies are used in various wearable devices, smartphones and other electric devices for convenience. Among these technologies, gesture recognition is the most commonly used and appropriate technology for wearable devices. Gesture recognition can be classified as contact or noncontact gesture recognition. This paper proposes contact gesture recognition with IMU and EMG sensors by using the hidden Markov model (HMM) twice. Several simple behaviors make main gestures through the one-stage HMM. It is equal to the Hidden Markov model process, which is well known for pattern recognition. Additionally, the sequence of the main gestures, which comes from the one-stage HMM, creates some higher-order gestures through the two-stage HMM. In this way, more natural and intelligent gestures can be implemented through simple gestures. This advanced process can play a larger role in gesture recognition-based UX for many wearable and smart devices.

• 한국전문물리치료학회지
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• 제16권3호
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• pp.32-41
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• 2009

The purpose of this study was to suppose basis data the influence of different chair type and pelvic control on quadriceps muscle activity and strength during knee joint extension isometric exercise in hemiplegic patients. This research were investigated in ten healthy adults and tens hemipelgic patients. Surface electromyography (EMG) and Biodex system were used to collect kinematic data and muscle activity, respectively. Independent t-test, paired t-test and one-way repeated ANOVA were used to determine a statistical significance. The results showed as follows: (1) Posterior pelvic angles in healthy group and hemiplegic group were significantly different on isokinetic equipment (p<.05). (2) Different chair type and pelvic control on quadriceps muscle activity and strength were significantly different in hemiplegic patients (p<.05). From the result of this research, posterior pelvic angle control during knee joint extension isometric exercise in hemiplegic patients on isokinetic equipment is necessary to increase quadriceps muscle strength in hemiplegic patients.