• 대한인간공학회지
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• 제34권1호
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• pp.11-18
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• 2015

Objective: The aim of this study was to understand the effects of phone weight on the typing performance and muscle recruitment in the neck and upper extremity while typing a text message with dominant hand. The iPhone4 and iPhone5 were compared due to their 28-gram differences in weight. Background: Too much use of a cellular phone can lead the musculoskeletal disorders in the upper extremity. Phone makers tend to make their new models bigger, lighter, faster and smarter. Method: Fourteen healthy volunteers without any history of neuromuscular disorders or ongoing pain who used their smartphone more than one year were recruited. A 112g phone (iPhone5) and a 142g phone (iPhone4) were used for typing the lyric of the Korean national anthem with their dominant hand. Typing duration, the typing error, the perceived fatigue, and preference was investigated. Muscle recruitment and the resting gap of neck (middle trapezius and levator scapula), shoulder (infraspinatus and mid deltoid), elbow (biceps brachii and brachioradialis), thumb (extensor and abductor policis brevis) were collected using surface electromyography. Typing error was counted and typing speed was calculated in characters per min. The data were analyzed using a paired t-test and chi-square (${\chi}^2$) analysis for the effects of phone weight on the typing performance parameters and muscle recruitment. Results: Typing text message with iPhone5 took longer but had less muscle recruitment in brachioradialis, and extensor policis brevis muscles. Lighter weight of iPhone5 made biceps brachii to rest less without increasing the mean %EMG. Conclusion/Application: Findings of this study can be valuable information for phone designers to develop more productive device and for smartphone users to prevent the musculoskeletal disorders in the upper extremities.

• 대한정형도수물리치료학회지
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• 제16권1호
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• pp.9-19
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• 2010

Purpose : To identify whether isometric shoulder horizontal extension (ISHE) exercise could sufficiently activate the lumbar multifidus muscle, and to determine appropriate exercise intensity to increase muscle strength. Methods : Twenty healthy volunteers (10 males and 10 females) participated in this study. ISHE exercises on the dominant side were performed with $90^{\circ}$ shoulder abduction held in $90^{\circ}$ elbow flexion so that their arms were in the horizontal plane. Electromyographic (EMG) measurements of multifidus activation were performed in standing and supine positions, and were taken under four strength conditions: 75%, 50% and 25% of maximum shoulder horizontal extension strength, and maximum strength. Results : The EMG activations of both lumbar multifidus increased significantly with ISHE exercises of larger % strength (p<.05). In their multifidus EMG data measured in standing and supine positions, men differed significantly in their 75%, 50% and 25% strength for both sides (p<.05), and women differed significantly in their 75%, 50% and 25% strength on their 5th lumbar vertebrae's left side, but 75% only for their 5th lumbar vertebrae's right side (p<.05). The EMG data of 5th lumbar vertebrae's left and 5th lumbar vertebrae's right sides appeared to differ significantly at all strength levels for men while standing, but only at the 25% level for women in the supine position (p<.05). These findings indicate that ISHE exercises can be considered a beneficial method to enhance the multifidus strength. Conclusion : This study provides useful information for further study in this field.

• 한국수소및신에너지학회논문집
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• 제31권2호
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• pp.169-176
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• 2020

There is a growing interest in hydrogen energy utilization since an alternative energy development has been demanded due to the depletion of fossil fuels. Hydrogen is produced by the reforming reaction of natural gas and biogas, and the electrolysis of water. An solid oxide electrolyte cell (SOEC) is reversible system that generates hydrogen by electrolyzing the superheated steam or producing the electricity from a fuel cell by hydrogen. If the water can be converted into steam by waste heat from other processes it is more efficient for high-temperature electrolysis to convert steam directly. The reasons are based upon the more favorable thermodynamic and electrochemical kinetic conditions for the reaction. In the present study, steam at over 180℃ and 3.4 bars generated from a boiler were converted into superheated steam at over 700℃ and 3 bars using a cylindrical steam superheater as well as the waste heat of the exhaust gas at 900℃ from a solid refuse fuel combustor. Superheated steam at over 700℃ was then supplied to a high-temperature SOEC to increase the hydrogen production efficiency of water electrolysis. Computational fluid dynamics (CFD) analysis was conducted on the effects of the number of 90° elbow connector for piping, insulation types and insulation layers of pipe on the exit temperature using a commercial Fluent simulator. For two pre-heater injection method of steam inlet and ceramic wool insulation of 100 mm thickness, the highest inlet temperature of SOEC was 744℃ at 5.9 bar.

• 한국정보전자통신기술학회논문지
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• 제13권3호
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• pp.267-276
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• 2020

제조업 근로자는 근무 환경에서 반복 작업에 의한 근골격계 질환의 위험에 쉽게 노출되어 있다. 이는 신체를 반복적으로 이용하는 직업 특성상의 문제에 기인한다. 하지만 현재 감시 및 예방을 위한 모니터링 시스템이 제공되지 않아 매년 위험에 대한 근로자의 노출도가 증가하고 있다. 본 논문에서는 IMU 센서를 사용한 웨어러블 장치 제작을 통해 실제 작업 환경에서의 이러한 문제를 해결하는 방법에 대해 제시한다. 웨어러블 형태의 장치를 착용 후, 근골격계 움직임에 따른 회전 값을 받아와 데이터 분석을 통해 사용자의 움직임을 판단해낸다. 이때, 바이어스 제거와 누적 오차를 제거해 정교한 데이터 취득하여 이를 동적 임곗값 형식으로 분석하여 사용자의 회전 운동 횟수를 측정해내어 위험도를 판단한다. 본 논문에서 제안한 웨어러블 장치를 이용 팔꿈치 근골격계 질환에 대한 회전 횟수를 측정하는 웹 페이지를 통해 본 방법의 효과를 확인할 수 있었다.

• 대한정형도수물리치료학회지
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• 제24권2호
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• pp.51-58
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• 2018

Backdround: Using RUSI (Rehabilitation Ultra Sound Imiging) method, which showed high reliability in soft tissue measurements, we compared the muscle relax and contraction, sex, and physical characteristics of the activity of the multifidus muscle in patients with chronic low back pain and normal subjects. Methods: In this study, 16 patients (male: 8, female: 8) with chronic low back pain and 16 healthy adult (male: 8, female: 8) were participated. Subjects lied prone posture on the table with elbow flexed $90^{\circ}$ and shoulder abducted $120^{\circ}$ (starting position). Test was applied two types that muscle relax position and muscle contraction position. Muscle relax position is equal to starting position and muscle contraction position is that upper extremity lift up about 5cm from the table. We measured the thickness of the multifidus muscle in each position by ultrasound. Results: There was a statistically significant difference between the two groups in deviation of Both Side Difference of Activated resting-Arm Lifting Ratio according to posture change between the chronic low back pain patient group and the normal group. Conclusion: The result of this study support previous study showing that there is an imbalance in the activity of multifidus in patients with chronic low back pain.

• 혜화의학회지
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• 제27권2호
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• pp.1-10
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• 2018

Objectives : The purpose of this study is to investigate the latest trend of studies on treatments of postoperative rotator cuff tear patients which are published in Korea. Methods : We investigated the studies on the treatments of postoperative rotator cuff tear patients via searching 6(six) Korean web databases(NSDL, RISS, Korean traditional knowledge portal, OASIS, KISTI, KCI). As a result, 16(sixteen) studies were found. We classified the papers by publication date, published journal, method of study, type of treatment, evaluation scale and referencing research ethics. Results : 16(sixteen) papers were published from 2006 to 2017. The papers were published in The journal of Korean shoulder & elbow society, The journal of korean acupuncture & moxibustion medicine, etc. 5(five) randomized controlled trials, 5(five) non-randomized controlled trials, 4(four) case reports and 2(two) Retrospective report have been found. For types of treatment, 6(six) exercise therapies, 3(three) Korean medicine treatments and 7(seven) other treatments have been found. Main evaluation tools were VAS, ROM, NRS and Muscle strength. Conclusions : In this study, we analyzed the latest trend of studies on treatments of postoperative rotator cuff tear patients. Reviewing the international trends of studies on treatments for postoperative rotator cuff tear are essential for the future studies.

• Investigative Magnetic Resonance Imaging
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• 제25권1호
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• pp.1-9
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• 2021

The aim of this study was to provide a new assessment of rotator cuff muscle activity. Eight male subjects (24.7 ± 3.2 years old,171.2 ± 9.8 cm tall, and weighing 63.8 ± 11.9 kg) performed the study exercises. The subjects performed 10 sets of the exercise while fixing the elbow at 90 degrees flexure and lying supine on a bed. One exercise set consisted of the subject performing external shoulder rotation 50 times using training equipment. Two imaging protocols were employed: (a) true fast imaging with steady precession (TrueFISP) at an acquisition time of 12 seconds and (b) multi-shot spin-echo echo-planar imaging (MSSE-EPI) at an acquisition time of 30 seconds for one echo. The main method of assessing rotator cuff muscle activity was functional T2 mapping using ultrafast imaging (fast-acquired muscle functional MRI [fast-mfMRI]). Fast-mfMRI enabled real-time imaging for the identification and evaluation of the degree of muscle activity induced by the exercise. Regions of interest were set at several places in the musculus subscapularis (sub), musculus supraspinatus (sup), musculus teres minor (ter), and deltoid muscle (del). We used the MR signal of the images and transverse relaxation time (T2) for comparison. Most of the TrueFISP signal was not changed by exercise and there was no significant difference from the resting values. Only the T2 in the musculus teres minor was increased after one set and the change were seen on the T2 images. Additionally, except for those after one and two sets, the changes in T2 were significant compared to those at rest (P < 0.01). We also demonstrated identify and visualize the extent to which muscles involved in muscle activity by exercise. In addition, we showed that muscle activity in a region such as a shoulder, which is susceptible to B0 inhomogeneity, could be easily detected using this technique.

• Physical Therapy Rehabilitation Science
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• 제11권3호
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• pp.356-362
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• 2022

Objective: Extracorporeal shock wave therapy (ESWT) is a nonsurgical treatment alternative to surgery for various musculoskeletal diseases that have traditionally been difficult to treat conservatively, including calcific tendinitis, tennis elbow, and plantar fasciitis. This study evaluated the effect of focused and radial shock wave therapy for calcific tendinitis of the shoulder. Design: Randomized controlled study Methods: Forty participants with calcific tendinitis were randomized into focused shock wave therapy (FSWT, n=20) and radial shock wave therapy (RSWT, n=20) groups. Patients were examined before and one week after treatment. Pain intensity was subjectively assessed using the visual analogue scale and function was assessed using the Constant-Murley score (CMS) and range of motion (ROM). Results: The results showed a significant decrease in pain and significant increase in shoulder mobility and function in both groups. However, FSWT was significantly more effective than RSWT, based on CMS and ROM assessment. Conclusions: Although it is possible to raise the energy intensity of RSWT to increase the depth at which the energy becomes dispersed, higher energy intensity is associated with a greater risk of severe neurovascular damage, and that high-intensity stimulation can cause adverse effects such as pain and petechiae. Therefore, FSWT is considered to be a safe and effective method for treating tendinous lesions while minimizing adverse effects. In conclusion, both FSWT and RSWT can reduce pain and increase mobility and function. FSWT can be considered as an alternative for calcific tendinitis of the shoulder.

• 척추신경추나의학회지
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• 제17권1호
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• pp.61-72
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• 2022

Objectives This study aimed to the application of Chuna manual therapy in patients with stroke where much evidence is not available. Methods Domestic databases (KOREANTK, OASIS, RISS, KISS, and KMBASE) were queried for literature showing application of Chuna manual therapy in stroke patients. Additionally, insufficient evidence was supplemented with expert consensus using the Delphi method. Based on the literature review and expert consensus, the academic committee of the Korean Society of Chuna Manual Medicine reviewed and summarized the Chuna technique recommendations that can be applied to stroke patients. Results There were six studies on Chuna manual therapy in stroke patients, and Chuna therapy was applied for pelvic, shoulder, and elbow joint spasticity. The expert Delphi survey did not agree with the application of the nine of the 69 standard Chuna techniques and deliberated on matters to be considered when applying Chuna manual therapy to stroke patients. Finally, based on clinical research literature and expert opinions, Chuna technique was recommended for patients with post-stroke spasticity. Conclusions The application of Chuna therapy to non-muscular skeletal disorders, including stroke is recommended and should be applied while taking the necessary precautions.

• Clinics in Shoulder and Elbow
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• 제13권1호
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• pp.40-46
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• 2010

목적: 골성 방카르트 병변이 있는 견관절 외상성 전방 불안정성 환자에서 두 가닥의봉합사를 가진 생체 흡수성 봉합 나사못를 이용한 새로운 수술 방법에 의한 관절경적 봉합술의 유용성을 알아보고자 한다. 대상 및 방법: 2005년 1월부터 2009년 3월까지 골성 방카르트 병변 봉합 술을 시행한 환자 중 12개월 이상 추시가 가능하였던 (평균 추시 기간 22.3개월, 범위 13~47개월) 17예를 대상으로 하였다. 남자 13예, 여자 4예였고, 우측이 14예 좌측이 3예였다. 평균 연령은 24세 (범위 17-42세)였다. 수상 시에서 수술까지의 기간은 평균 2년 (범위, 10개월-4년 1개월)이었다. 수술 방법은 두 가닥의 봉합사를 가진 봉합 나사못을 골편이 떨어진 관절 와에 고정한 후 하나의 봉합사를 골편을 둘러싸 고정 시킨 후 또 다른 봉합사를 이용하여 주변 관절 낭을 떠서 고정한 골편을 둘러 싼 후 봉합하였다. 술 후 결과는 Rowe의 평가 방법과 KSS 평가지수를 이용하였고 관절 와의 결손부위와 골편은 삼차원 입체 컴퓨터 단층 촬영을 이용하여 측정하였다. 결과: 수술 후 최종 추시상 Rowe 견관절 평가지수는 평균 54점 (범위 23~71점)에서 83.4점 (71~90점)으로 전반적으로 향상되었고, 전체적으로 우수 13예 (76%), 양호 3예 (18%), 보통 1예 (6%)였다. KSS 점수는 수술 전 평균 71점 (범위 49~82점)에서 수술 후 92.5점 (범위 82~94점)으로 향상하였다. 최종 추시상 통증이 지속되는 예는 없었으며, 추시기간 동안 재 탈구 된 예는 없었다. 수술 후 삼차원 입체 컴퓨터 단층 촬영이 시행되었던 6예에서 골 유합을 확인할 수 있었다. 결론: 견관절 외상성 불안정성에 대한 골성 방카르트 병변의 두 가닥의 봉합사를 가진 생체 흡수성 봉합나사못을 이용한 새로운 수술 방법에 의한 골성 방카르트 병변 봉합술은 우수한 임상결과와 낮은 재발율을 보이고, 합병증이 낮아 골성 방카르트 병변의 치료에 하나의 대안이 될 수 있을 것이라 사료 된다.