• 대한인간공학회지
• /
• 제35권6호
• /
• pp.595-609
• /
• 2016

Objective: The purpose of this study was to develop and validate the guidelines for Medic Work Table (MWT) based on the anthropometric data of medical technologists. Background: Users' anthropometric data such as sitting height, sitting elbow height, knee height, and so on are significant factors for designing comfortable and useful furniture. Thus, many guidelines for different types of desks and chairs based on the users' anthropometric data have been suggested to many researchers. However, few researches have been conducted to provide design guidelines for MWT for blood collecting task. Medical technologists often use their upper extremities to perform blood collecting task with high repetitions. These repeated motions could be a critical factor in the prevalence rate of Work-related Musculoskeletal Disorders (WMSDs). Therefore, a study on ergonomic design of MWT would be essential in preventing the WMSDs and improving the quality of the working environment of medical technologists. Method: This study suggested design guidelines for ergonomic MWT by focusing on the heights of the upper side and underside, depths of the inside and outside, and width of MWT through anthropometric studies and literature reviews. Afterwards, a new MWT was made using the suggested design guidelines for this study. Five healthy medical technologists participated to evaluate the original MWT and new MWT. All participants took part in the range of motion (ROM) test, electromyography (EMG) muscle activity test, and usability test to validate the suggested guidelines in this study. EMG signals of related muscles (Flexor Carpi Ulnaris, Extensor Carpi Ulnaris, Deltoid Anterior, and Biceps Branchii) were recorded through the surface electromyography system from both the original MWT and the new MWT. The ROM test of the shoulder and elbow flexion was also assessed using motion sensors. Results: The newly designed MWT showed decreased ROMs of the shoulder and elbow up to 22% and 18% compared to the original MWT. The muscle activities in the new MWT also showed a decrease of 13% in Anterior Deltoid, 6% in Biceps Brachii, 5% in Flexor Carpi Ulnaris, and 8% in Extensor Carpi Ulnaris muscle groups, compared to the original MWT. In the usability test, the satisfaction score of the new MWT was also 56.1% higher than that of the original MWT. Conclusion: This study suggested guidelines for designing MWT and validating the guidelines through qualitative and quantitative analyses. The results of motion analysis, muscle activity, and usability tests demonstrated that the newly designed MWT may lead to less physical stress, less awkward posture, and better physical user interface. Application: The recommended guidelines of the MWT would be helpful information for designing an ergonomic MWT that reduces physical loads and improves the performance of many medical technologists.

• 대한의용생체공학회:의공학회지
• /
• 제33권2호
• /
• pp.65-71
• /
• 2012

In this paper, the Gaussian Mixture Model(GMM) which is very robust modeling for pattern classification is proposed to classify wrist motions using surface electromyograms(EMG). EMG is widely used to recognize wrist motions such as up, down, left, right, rest, and is obtained from two electrodes placed on the flexor carpi ulnaris and extensor carpi ulnaris of 15 subjects under no strain condition during wrist motions. Also, EMG-based feature is derived from extracted EMG signals in time domain for fast processing. The estimated features based in difference absolute mean value(DAMV) are used for motion classification through GMM. The performance of our approach is evaluated by recognition rates and it is found that the proposed GMM-based method yields better results than conventional schemes including k-Nearest Neighbor(k-NN), Quadratic Discriminant Analysis(QDA) and Linear Discriminant Analysis(LDA).

• 대한의용생체공학회:의공학회지
• /
• 제26권5호
• /
• pp.257-264
• /
• 2005

This paper proposes an ionic polymer metal composite (IPMC) based artificial muscle to be applicable to the Myoelectric hand prosthesis. The IPMC consists of a thin polymer membrane with metal electrodes plated chemically on both faces, and it is widely applying to the artificial muscle because it is driven by relatively low input voltage. The control commands for the IPMC-based artificial muscle is given by electromyographic (EMG) signals obtained from human forearm. By an intended contraction of the human flexor carpi ulnaris and extensor carpi ulnaris muscles, we investigated the actuation behavior of the IPMC-based artificial muscle. To obtain higher actuation force of the IPMC, the single layered as thick as $800[{\mu}m]$ or multi-layered IPMC of which each layer can be as thick as $178[{\mu}m]$ are prepared. As a result, the bending force was up to the maximum 12[gf] from 1[gf] by actuating the single layered IPMC with $178[{\mu}m]$, but the bending displacement was reduced to 6[mm] from 30[mm]. The experimental results using an implemented IPMC control system show a possibility and a usability of the bio-mimetic artificial muscle.

• 재활복지공학회논문지
• /
• 제6권1호
• /
• pp.67-73
• /
• 2012

본 논문에서는 표면 근전도 신호를 사용하여 손목 움직임의 동작을 분류하기 위해 인공 신경 회로망(ANN : Artificial Neural Network)기반의 동작 분류 알고리즘을 제안한다. 손목 움직임에 무리가 없는 20~30대 성인 26명을 대상으로 척측 수근 굴근과 척측 수근 신근에 부착한 2채널의 전극으로부터 표면 근전도 신호를 취득하고, 취득한 근전도로부터 손목의 굴곡, 신전, 내전, 외전, 휴식 다섯 동작을 인식한다. 빠른 처리 속도를 위해 획득한 신호로부터 시간 영역에서의 특징점을 추출하고 ANN을 이용한 동작 분류에 사용된다. 특징점으로 DAMV, DASDV, MAV, RMS를 사용하였으며, ANN 기반의 동작 분류의 인식율은 DAMV는 98.03%, DASDV는 97.97%, MAV는 96.95%, 그리고 RMS는 96.82%의 정확도를 나타낸다.

• International Journal of Contents
• /
• 제16권1호
• /
• pp.57-64
• /
• 2020

We sought to compare upper extremity muscle activity between handwriting on paper and touchscreen with dominant and non-dominant hands in younger adults (age 23.90±1.12) and the elderly (age 75.55±5.76). Muscle activity (percent of maximum voluntary contraction) in the biceps brachii muscle, triceps brachii muscle, flexor carpi ulnaris muscle, and extensor carpi ulnaris muscle was measured using an electromyography device. As a result, our data indicate that muscle activity is lower in younger adults than the elderly. Besides, muscle activity is lower in the dominant versus non-dominant hand, and lower when writing using a touchscreen than on paper. These results can be used to support recommending touchscreens in the elderly. Also, they can be used as baseline data for comparing the performance of non-paretic side and paretic side in patients relative to the central nervous system.

• 한국운동역학회지
• /
• 제16권3호
• /
• pp.95-103
• /
• 2006

The purpose of this study was to analyze a change of maximal grip forces and EMG of agonists in upper extremity of 8 professional Ssirum players according to Satbar-grip patterns, to elucidate prime agonist muscles, contribution rate of each muscle, and a difference on EMG in upper extremity. one-way ANOVA(RM) performed for average and maximal values of each player after standardization and statistical significance was set as p<.05. The result includes the following: the highest grip force was A type with a statistic significance using one-way ANOVA and Duncan's comparison between A and C type. In summary the highest grip force was exerted on extension in the wrist than flexion in all grip types. Average and maximal values of biceps brachii and brachioradialis muscles were statistically significant and ones of flexor carpi ulnaris and extensor capi ulnaris were not.

• 대한정형외과스포츠의학회지
• /
• 제11권1호
• /
• pp.8-16
• /
• 2012

스포츠 활동에 대한 참여도가 높아짐에 따라 스포츠 손상의 발생빈도도 증가되고 있으며 특히 손목 부위는 상지의 다른 부위에 비해 손상의 빈도가 높다. 손목 스포츠 손상은 일반적으로 과다 사용 손상과 외상성 손상으로 분류되고 있는데 이 중 외상성 손상은 과격한 접촉이나 충돌이 필요로 하는 운동에서 나타나며 주로 골절, 탈구 및 인대 파열과 같은 급성 손상을 의미한다. 과다사용 손상은 미세한 외상이 반복적으로 가해져 결국은 생체내 회복 능력을 벗어나 정상적인 조직에 손상을 주게 되어 나타나는 드 꿰르벵 병, 척 수근 신건염, 교차 증후군 등의 염증성 병변은 물론 유구골구 피로 골절, 척 수근 신건의 아탈구, 만성 주상 월상골간 불안정, 삼각섬유연골 복합체의 퇴행성 파열 등과 같은 만성 외상성 병변을 포함한다. 저자는 손목의 과다사용 및 외상성 병변과 관련된 스포츠 손상을 기술하고 특히 각 손상의 진단, 보존적 및 수술적 치료의 장점과 단점 등에 초점을 맞추어 기술하고자 한다.

• 혜화의학회지
• /
• 제14권1호
• /
• pp.67-81
• /
• 2005

We have conclusions after the study of muscular system about small intestine channel of hand taiyang muscle. Judging from many studies of interrelation between Meridian muscle and muscle, it is considered that Meridian muscle theory has some similarities with modern anatomical muscular system. It is considered that Small intestine channel of hand taiyang muscle contains Flexor digitorum profundus muscle, Extensor digiti minimi muscle, Abductor digiti minimi muscle, Extensor carpi ulnaris muscle, Flexor carpi ulnaris muscle, Triceps brachii muscle, Infraspinatus muscle, Levator scapulae muscle, Sternocleidomastoid muscle, Masseter muscle, Temporalis muscle. The symptoms of small intestine channel of hand taiyang muscle is similar to referred pain of modern Myofascial Pain Syndrome, and the medical treatment of "I Tong Wi Su(以痛爲輸)" is also similar to that of Myofascial Pain Syndrome. Small intestine channel of hand taiyang muscle is one of the three yang channels of hand muscle, and it has unity in extension of upper limb and trunk in the movement. And it is thought that weakness of small intestine channel of hand taiyang muscle is related with muscular system causing Round Shoulder and Head Forward Position.

• 한국전문물리치료학회지
• /
• 제16권2호
• /
• pp.67-76
• /
• 2009

In order to prevent upper extremity musculoskeletal disorders, effective keyboard selection is an important consideration. The aim of this study was to compare upper extremity muscle activity according to transverse plane angle changes during vertical keyboard typing. Sixteen healthy men were recruited. All subjects had a similar typing ability (rate of more than 300 keystrokes per minute) and biacromion and forearm-fingertip lengths. Four different types of keyboard (vertical keyboard with a transverse plane angle of $60^{\circ}$, $96^{\circ}$, or $120^{\circ}$, and a standard keyboard) were used with a wrist support. The test order was selected randomly for each subject. Surface electromyography (EMG) was used to measure upper extremity muscle activity during a keyboard typing task. The collected EMG data were normalized using the reference contraction and expressed as a percentage of the reference voluntary contraction (%RVC). In order to analyze the differences in EMG data, a repeated one-way analysis of variance, with a significance level of .05, was used. Bonferroni correction was used for multiple comparisons. There were significant differences in the EMG amplitude of all seven muscles (upper trapezius, middle deltoid, anterior deltoid, extensor carpi radialis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris) assessed during the keyboard typing task. The mean activity of each muscle had a tendency to increase as the transverse plane angle increased. The mean activity recorded during all vertical keyboard typing was lower than that recorded during standard keyboard typing. There was no significant difference in accuracy and error scores; however, there was a significant difference between transverse plane angles of $60^{\circ}$ and $120^{\circ}$ with regard to comfort. In conclusion, a vertical keyboard with a transverse plane angle of $60^{\circ}$ would be effective in reducing muscle activity compared with vertical keyboards with other transverse plane angles.

• 대한산업공학회지
• /
• 제37권3호
• /
• pp.209-215
• /
• 2011

The objective of this study was to determine whether there are differences in hand muscle activities (APB : abductor pollicis brevis, ED : extensor digitorum, ECU : extensor carpi ulnaris, and EI : extensor indicis) and subjective discomfort according to the three mouse sizes (small, medium, large) and two task types (pointing and scrolling). The mouse size and task type showed significant interaction effects on the total NEMG (p = 0.004) and on the NEMG of the abductor pollicis brevis muscle (p = 0.001). The total NEMG and the NEMG of APB showed the highest value in the 'scrolling' task using the 'small' mouse. However, the NEMG of the EI was different according to the mouse size, and the 'small' mouse showed the lowest value. The subjective discomfort was the lowest in the 'medium' mouse, and all nine subjects preferred the 'medium' size. The hand-size related anthropometric variables showed different correlations according to the task type and mouse size with the NEMGs and subjective discomfort. The results of this study could be used as a basic information for the determination of the proper mouse size according to the hand size.