• Proceedings of the KSME Conference
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• 2002.08a
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• pp.71-74
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• 2002

Fluid flow in a rectangular duct system are measured by W laser doppler velocity meter, and also computed by commercial software of STAR-CD for comparison between then First, for a rectangular duct with 90 degree metered elbow, the fluid flow with Reynolds numbs's of 1,508 is predicted by assumption of both laminar and turbulent models. But, even though the Reynolds number is less than 2,300-3,000, the computation by turbulent model is close to the experimental data. Moeover, the computation by turbulent model for Reynolds number of 11,751 also predicts the experimental data satisfactorily. Second, for a rectangular duct with two branch ducts, the ratios between flow rates in the two branches are invariant to Reynolds number according to both of numerical and experimental results.

• Journal of the Korea Safety Management & Science
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• v.8 no.4
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• pp.13-23
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• 2006

Grip strength provides a quick and objective index of the functional integrity of the upper extremities. It is widely used as an assessment measure in physical and rehabilitation medicine. In this study, maximum voluntary grip strength of 20 college students wearing 5 different gloves were measured using Jamar hand dynamometer. The results show that maximum voluntary grip strength was generally reduced when wearing gloves as compared to bare-handed. More specifically, the grip strength was highest when wearing PVC coated glove or bare-handed and getting lowered as wrist band, rubber, leather, and cotton glove in these order. Depending on the measuring posture of grip strength, shoulder height with arm extended forward was higher than the elbow was flexed 90 degree. Moreover, subjects' demographic factors and hand dimensions were not closely related to the grip strength. It is thus recommended that the proper glove should be provided to reduce the negative consequences including dropping a tool, poorer control of a tool. lower quality work, and increased muscle fatigue and in turn to increase the user safety and satisfaction.

• Physical Therapy Rehabilitation Science
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• v.6 no.3
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• pp.152-157
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• 2017

Objective: The aim of this study was to determine the intra-rater and inter-rater reliability of the dual rehabilitative ultrasound imaging (D-RUSI) when simultaneously measuring muscle thickness changes at rest and during co-contraction of the biceps brachii (BB) and triceps brachii (TB). Design: Cross-sectional study. Methods: This study included 36 healthy participants (23 men, 13 women). The participants sat on a chair in a comfortable position with a cushion placed under their elbow to maintain a 90-degree elbow flexion angle. The muscle thickness of the biceps brachii and triceps brachii was measured twice using the D-RUSI by two examiners during resting and co-contraction states. One week later, the same procedure was performed once again. Results: The intra-class correlation coefficients (ICCs) for intra-rater reliability ranged from 0.887 to 0.989 and the confidence interval was within an acceptable range of 0.778 to 0.994. The standard error of measurement (SEM) values ranged from 0.303 to 0.866 and the minimal detectable change (MDC) values ranged from 0.84 to 2.40. The ICCs for inter-rater reliability ranged from 0.758 to 0.925. The SEM values ranged from 0.702 to 1.486 and the MDC values ranged from 1.95 to 4.12. Conclusions: The use of the D-RUSI of the BB muscle had a very good intra-rater reliability and very good inter-rater reliability at the resting state, and a, good inter-rater reliability at the co-activation state. ICC values showed very good intra-reliability and inter-reliability for the TB muscle. the D-RUSI is a useful tool for simultaneously measuring the thickness of two muscles when the BB is an agonist and the TB is an antagonist during co-activation of the upper arm.

• Korean Journal of Occupational Health Nursing
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• v.14 no.2
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• pp.164-170
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• 2005

Purpose: The present study attempted to find subjective musculoskeletal symptoms of operating room nurses (OR nurses) and then to use them as basic data for prevention and management of musculoskeletal symptoms of OR nurses. Method: This study was an exploratory research, and data were collected from OR nurses working in 8 polyclinics in Korea from July 26 to August 19, 2004, using a self-report questionnaire. The questionnaire contains items concerned with subjective musculoskeletal symptoms include ones with the presence of symptoms and with the degree of discomfort, in the joints such as neck, shoulder, arm/elbow, hand/wrist/finger and waist. For data collection, the aim of the study was explained to the operating room managers to obtain their help, and these questionnaires were sent to hospitals, and were retrieved by post. 271(90.3%) questionnaires were returned among those sent to 300 nurses. 249 questionnaires excluding 22 insufficient ones such as no response were used for data analysis. Data were analyzed using SPSS WIN 12.0. Subjective musculoskeletal symptoms were analyzed in the number and percentage. Result: 187(75.1%) nurses said they 'had' subjective musculoskeletal symptoms and 62 (24.9%) said they had 'nothing'. 130(52.2%), 125 (50.2%), 113 (45.4%), 86(34.5%), and 42 (16.9%) nurses had subjective musculoskeletal symptoms in waist, shoulder, hand/wrist/finger, neck, and arm/elbow, respectively. 51(27.3%) and 136 (72.7%) nurses complained of the pain in one site, and in two or more sites, respectively. In particular, 51% and 47.4% nurses said that they were 'discomforted' due to the pain in waist and in shoulder, respectively. Conclusion: Subjective musculoskeletal symptoms which OR nurses complained of were significant. This may cause difficulty in nursing tasks in the operating room. So various arrangements have to be made for OR nurse with subjective musculoskeletal symptoms at an early stage.

• Clinics in Shoulder and Elbow
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• v.1 no.2
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• pp.175-179
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• 1998

The acromioclavicular joint is commonly affected by traumatic and degenerative conditions. Most injuries are due to direct trauma, such as a fall on the shoulder. Although there is general agreement on treatment of type I, Ⅱ, Ⅳ, V and VI acromioclavicular injuries, the treatment of type Ⅲ injuries remains controversial. Sixty patients, ranging in age from 19 to 57 years(average, 32), were evaluated an average of 57.5 (range, 13 to 96) months after surgical reconstruction for Rockwood type Ⅲ Ⅳ, V acromioclavicular dislocation. Phemister method (47 cases), Bosworth (3 cases), Weaver and Dunn method (10 cases) were used to correct displacement. An increase of the coracoclavicular distance of the injured shoulder over the normal shoulder was average 7.1㎜ at initial, average l㎜ on postoperatively, and average 2㎜ at follow-up. Overall, 54 of 60(90%) patients achieved satisfactory results. Degree of increase of the coracoclavicular distance has no inliluence to clinical results.

• Clinics in Shoulder and Elbow
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• v.18 no.2
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• pp.86-90
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• 2015

Background: Although there are several methods for evaluating bone quality, Hounsfield units (HU), a standardized computed tomography (CT) attenuation coefficient, provide a useful tool for estimating focal bone mineral density (BMD). The aim of this study is to investigate the HU for evaluating the degree of osteoporosis in greater tuberosity with regard to anchor positioning. Methods: Forty patients diagnosed as normal on shoulder CT were included and categorized according to age and gender. Axially sectioned CT images were processed to 3-dimensional models containing information about bone quality using Mimics (14.11 platform v14.1.1.1 Materialise). Three-dimensional anchors were simulated and positioned according to 6 regions of interest (ROI) in the greater tuberosity classified using Tingart's system. Mean HU of intra-anchor volumes in the 6 regions was measured. Results: A significant decrease in HU was observed with increasing age (p=0.0001) and menopause (p<0.001). A significant difference in HU was found between male and female groups with males showing the higher values (p=0.0001). HU of proximal areas of ROI was higher than those of distal areas (p<0.005). However, although mean HU of distal posterior ROI showed the lowest values, no statistically significant difference was found between anterior, middle, and posterior regions (p=0.087). Conclusions: Mean HU of ROIs provides a tool for preoperative assessment of focal BMD, which is a factor of suture anchor stability and can be used to aid decision-making regarding secure anchor positioning for rotator cuff repair. Our data support that the most secure point is the proximal regions of ROI.

• Clinics in Shoulder and Elbow
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• v.8 no.1
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• pp.23-30
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• 2005

Purpose: This paper analyzes the results of arthroscopic bankart repair for anterior recurrent dislocation following a trauma on shoulder. Material and Methods: The subjects were twenty-three (23) cases that were available to follow up for more than eighteen months during the period from November 2001 to June 2003 and were chosen from patients to whom arthroscopic bankart repair was applied using a knotless suture anchor for their traumatic anterior recurrent dislocation on the shoulder. Their average age was 28 (ranging from 15 to 60) with 20 males and 3 females. The injury from sports activities accounted for the most cases with 14 subjects. The average follow-up period was 27 months (ranging from 18 months to 35 months). There were 19 cases of bankart lesions, 4 cases of ALPSA lesions and associated with 5 cases of partial tear in the rotator cuff. The anchors employed were knotless anchor (Mitek) for all the cases. Rowe scoring scale was adopted to judge the results after operations. Patients' subjective satisfaction and range of motion of external rotation were addressed together. Results: Rowe scores showed that 20 cases (87%) reaches the level of 'good' and hinger. The average patients' satisfaction accounted for 90 points out of 100. It was also found that external rotations averagely decreased by 6.5 degree when the range of motion was in at the side. Conclusion: There were satisfactory results of arthroscopic bankart repair using knotless suture anchors as an operative treatment for traumatic anterior recurrent dislocation on shoulder.

• Clinics in Shoulder and Elbow
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• v.17 no.2
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• pp.57-63
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• 2014

Background: To compare the effect of different starting periods of rehabilitative exercise (early or delayed passive exercise) on the rate of retear and other clinical outcomes after the arthroscopic repair of the rotator cuff. Methods: In total, 103 patients who underwent arthroscopic repair of the rotator cuff were included in the study. Determined at 2 weeks post-operation, patients who were incapable of passive forward elevation greater than $90^{\circ}$ were allotted to the early exercise group (group I: 79 patients; 42 males, 37 females), whilst those capable were allotted to the delayed exercise group (group II: 24 patients; 14 males, 10 females). The group I started passive exercise, i.e. stretching, within 2 weeks of operation, whilst group II started within 6 weeks. The results were compared on average 15.8 months (11-49 months) post-operation using the passive range of motion, the Visual Analog Scale (VAS) pain score, and the University of California at Los Angeles (UCLA) and Constant scores. Stiffness was defined as passive forward elevation or external rotation of less than $30^{\circ}C$ compared to the contralateral side. Follow-up magnetic resonance imaging (MRI) was carried out on average 1 year post-operation and the rate of retear was compared with Sugaya's criteria. Results: There were no differences between the two groups in gender, age, smoking, presence of diabetes, arm dominance, period of tear unattended, pre-operative range of motion, shape and size of tear, degree of tendon retraction, and tendon quality. There were no significant differences in clinical outcomes. Whilst stiffness was more frequent in group II (p-value 0.03), retear was more frequent in group I (p-value 0.028) according to the MRI follow-up. Conclusions: During rehabilitation after the arthroscopic repair of the rotator cuff, the delay of passive exercise seems to decrease the rate of retear but increase the risk of stiffness.

• Clinics in Shoulder and Elbow
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• v.25 no.1
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• pp.5-14
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• 2022

Background: The purpose of this study was to verify the effect of protocatechuic acid (PCA) on tendon healing and fatty degeneration in a chronic rotator cuff model. Methods: Twenty-eight Sprague-Dawley male rats were randomly allocated into two groups: Saline+repair (SR) and PCA+repair (PR). The right shoulder was used for experimental interventions, and the left served as a control. PCA (30 mg/kg/day) was administered intraperitoneally at the site of infraspinatus tendon detachment in rats in the PR group, and the same volume of saline was administered to the same site in the SR group. The torn tendon was repaired 4 weeks after infraspinatus detachment. Four weeks after repair, hematoxylin and eosin (H&E), S100, and CD68 stains were performed to evaluate the degree of fatty degeneration and H&E and Masson trichrome stains were performed to assess tendon healing. Superoxide dismutase (SOD) was measured to test the efficacy of PCA as an antioxidant. Results: Results from histological evaluation indicated that SOD and CD68 levels at the musculotendinous region and collagen fiber parallel to the orientation at the tendon-to-bone junction were not significantly different between the SR and PR groups. The mean load-to-failure of the PR group (20.32±9.37 N) was higher than that of the SR group (16.44±6.90 N), although this difference was not statistically significant (p=0.395). The SOD activity in the operative side infraspinatus muscle of the PR group was higher than that of the SR group, but the difference was not statistically significant (p=0.053). Conclusions: The use of PCA could improve tendon healing and decrease fatty degeneration after rotator cuff repair.

• Clinics in Shoulder and Elbow
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• v.3 no.2
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• pp.87-94
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• 2000

Purpose : The purpose of this study was to evaluate the activity of the biceps brachii muscle in the vulnerable abduction and external rotation position of the shoulder in patients with anterior instability. Materials and Methods: This experimental study include a prospective analysis of the electromyographic(EMG) data on a group of patients with traumatic unilateral anterior instability of the shoulder. The EMG data of unstable shoulders was compared with those of opposite shoulders as control. The optimal sample size for the case-control study was calculated using an nQuery Advisor program(nQuery Adviser 3.0, Statisticl solutions Ltd., Ireland). The EMG analyses were conducted in 76 shoulders in 38 patients who had a traumatic anterior instability in one shoulder. The EMG records were obtained at different position of shoulder, which included 0° , 45° , 90° and 120° of shoulder abduction. In each angle of shoulder abduction, the arms were placed in an external rotation as tolerated by the anterior apprehension. The paired-sample T test was used to compare the difference of the root mean square(RMS) voltages between the stable and unstable shoulders in each degree of arm position. Results : The RMS voltage of the biceps muscle was significantly greater in the unstable shoulder than opposite stable shoulder in all position of the arm(p<0.001). The RMS voltage of the biceps was maximal at 90° and 120° of external rotation in the unstable shoulder(p<0.05). The RMS voltage of the supraspinatus muscle revealed no differences in any of the test conditions(p=0.904, 0.506, 0.119 and 0.781 in 0° , 45° , 90° and 120° , respectively) Conclusion: In the vulnerable abduction and external rotation position, the biceps muscle plays an active compensatory role in the unstable shoulder while not in the stable shoulder.