• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.377-383
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• 2003

In this study, the methodology for determination of shoulder height in the internal shape design of ball bearing using 3D contact analysis is proposed. The quasi-static analysis of a ball bearing was performed to calculate the distribution of applied contact load and angles among the rolling elements. From each rolling element loads and the contact geometry between ball and inner/outer raceway, 3D contact analyses using influence function are conducted. These methodology is applied to HDD ball bearing. The critical axial load and the critical shoulder height which are not affected by edge in the present shoulder height is calculated. The proposed methodology may be applied to other rolling element bearing for the purpose of reducing the material cost and improving the efficiency of the bearing design process.

• Clinics in Shoulder and Elbow
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• 제18권1호
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• pp.13-20
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• 2015

Background: The purpose of this study is to assess the range of shoulder motion using an indirect evaluation method without physical examinations of patients based on questionnaires regarding several specific arm postures referenced by patient's own body parts. Methods: Nine criteria of specific shoulder motion including 4 forward flexion, 2 external rotation, and 3 internal rotation were decided as reference position which can represent a certain shoulder motion. Flexion contains postures such as lifting arm to waist-height, shoulder-height, eye-height, and raising arm above head with arm touching ears. External rotation comprises grasping ears and placing hands on back of the head. Vertebral height in internal rotation is determined by calculating the samples' motions, which are holding on to trouser belts, opposite-elbow, and scapula. These postures are included in questionnaires for patients to evaluate the validity and effectiveness of this indirect method. Results: The range of flexion was $77^{\circ}$ ($60^{\circ}$ to $100^{\circ}$), $96^{\circ}$ ($87^{\circ}$ to $115^{\circ}$), $135^{\circ}$ ($115^{\circ}$ to $150^{\circ}$), and $167^{\circ}$ ($150^{\circ}$ to $175^{\circ}$) when arms go up to waist, shoulder, eye, and high vertically. Range of external rotation was $39.6^{\circ}$ ($30^{\circ}$ to $50^{\circ}$) when grasping ears and $69.2^{\circ}$ ($60^{\circ}$ to $80^{\circ}$) with the hands on the back of the head. Range of internal rotation was L4 when placing trouser belts, T12 for holding opposite elbow, and T9 for reaching scapula. The mismatch rates of flexion, external rotation, and internal rotation were 11.6%, 9.6%, and 7.8%. Conclusions: The range of shoulder motion using this method is expected to be applied to an established shoulder scoring system which included shoulder motion evaluation item.

• 대한통합의학회지
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• 제11권4호
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• pp.213-220
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• 2023

Purpose : The purpose of this study is to investigate the effect of each lower trapezius muscle exercise performed according to the abduction position (Y type - shoulder joint abduction 145 °, T type - shoulder joint abduction 90 °, and MPC type - shoulder joint 45 ° abduction) of the shoulder joint on the muscle activity of the round shoulder and lower trapezius muscle. Methods : This study was conducted on 31 adult men and women. Through random assignment, they were assigned to the Y group, T group, and MPC group. A 4-week intervention was performed for each group of 31 subjects who participated in the experiment, and shoulder height and lower trapezius muscle activity were measured before and after the intervention. Shoulder height measurement is a test to measure rounded shoulder posture. When the value is low, it means that rounded shoulder posture is improved. The muscle activity of the lower trapezius muscle was measured using the %MVIC method, and when the value is high, it means that the lower trapezius muscle is active. All measured data were verified using dependent t-tests for before and after comparisons and one-way analysis of variance for comparisons between groups. Results : The results of this study showed a significant decrease after intervention only in shoulder height. Muscle activity of the lower trapezius muscle decreased after intervention, but did not show a significant difference. Both variables showed no significant differences between groups. Conclusion : The results of this study show that three lower trapezius muscle exercises were performed on subjects in rounded shoulder posture. All three groups showed a significant decrease in the shoulder height value, a method of measuring rounded shoulder posture, and no significant differences between groups could be confirmed. Therefore, all three exercises can be considered effective in reducing shoulder posture.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.187-197
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• 2013

PURPOSE. The purpose of this study was to evaluate various core designs on stress distribution within zirconia crowns. MATERIALS AND METHODS. Three-dimensional finite element models, representing mandibular molars, comprising a prepared tooth, cement layer, zirconia core, and veneer porcelain were designed by computer software. The shoulder (1 mm in width) variations in core were incremental increases of 1 mm, 2 mm and 3 mm in proximal and lingual height, and buccal height respectively. To simulate masticatory force, loads of 280 N were applied from three directions (vertical, at a $45^{\circ}$ angle, and horizontal). To simulate maximum bite force, a load of 700 N was applied vertically to the crowns. Maximum principal stress (MPS) was determined for each model, loading condition, and position. RESULTS. In the maximum bite force simulation test, the MPSs on all crowns observed around the shoulder region and loading points. The compressive stresses were located in the shoulder region of the veneer-zirconia interface and at the occlusal region. In the test simulating masticatory force, the MPS was concentrated around the loading points, and the compressive stresses were located at the 3 mm height lingual shoulder region, when the load was applied horizontally. MPS increased in the shoulder region as the shoulder height increased. CONCLUSION. This study suggested that reinforced shoulder play an essential role in the success of the zirconia restoration, and veneer fracture due to occlusal loading can be prevented by proper core design, such as shoulder.

• 복식문화연구
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• 제24권5호
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• pp.617-625
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• 2016

In women's clothing the shoulders are distorted and exaggerated. Consequently, the wearers' bodies are transformed and interpreted according to modern standards. We therefore refer to this aspect of women's clothing as the power shoulder. This study aims to analyze the differences in sensibility images on variations in the shoulder shape of power shoulder jackets. Nine samples were examined that involved combinations of three variations of the shoulder height and three variations of the shoulder width. The data was evaluated by 123 fashion design majors. Four factors were selected: attractiveness, personality, activity, and self-respect. Among these factors, attractiveness is the most important. The study results indicated that changes in shoulder height acted as a major effect that had an independent influence on all four factors. In contrast, changes in shoulder width acted as a major effect that had an independent influence on attractiveness, personality, and activity but not on self-respect. It also had an influence on the interaction effect of attractiveness, personality, activity, and self-respect. We anticipate that this study will help individual customers select clothing that is suitable for their preference and body shape because it is now possible for them to estimate images of power shoulder jackets.

• 한국의상디자인학회지
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• 제13권1호
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• pp.59-71
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• 2011

As an exaggerated-shoulder becomes a growing trend women's clothing, the crescent shaped sleeve with parallel style lines in the arm hole is a highly used women's sleeve pattern. This study develops and provides an applicable method for making the crescent shaped power shoulder sleeve. An efficient basic method for making the 2 piece crescent shaped sleeve was developed and the sensory appearance test was carried out with experimental clothes. There are two principles for making the crescent shaped sleeve: having a style line in the sleeve and pasting part of the cut arm hole of the bodice to the sleeve. The latter would be more convenient for a 2 piece sleeve, mostly used for jackets. The crescent shaped sleeve used in power shoulder jackets should set the shoulder angle as you wish to extend and raise the shoulder point of the bodice and sleeve to the same height. For a stronger power shoulder image, a 3 piece sleeve has a better appearance. Also, the height of the shoulder has to be enhanced with a shoulder pad for a more stable sleeve.

• The Journal of Korean Physical Therapy
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• 제35권3호
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• pp.83-88
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• 2023

Purpose: This study was to investigate the effect of forward head posture (FHP) and round shoulder posture (RSP) on changes in muscle activities according to shoulder flexion and abduction tasks. Methods: Twenty-two male subjects with no history of neurological, musculoskeletal surgery or injuries, or pain in the spine region within the previous 3-month periods were recruited for this study. Craniovertebral angle (CVA) and Scapula Index were measured before performing 90° abduction and flexion tasks holding a 3kg dumbbell. Muscle activities were measured during the tasks. All measurements except height of the acromion were carried out in a sitting position at the height of the subject's knee angle of 90 degrees, and two tasks were randomly performed with the arm that the subject mainly use to throw the ball. The abduction and flexion angles were checked by the examiner using a goniometer beside the subject. Results: Correlation coefficient analysis between Scapular Index and upper trapezius muscle activity during shoulder abduction task showed significant positive correlation. No significant correlation was observed between CVA, Scapular Index, and other muscle activities. Conclusion: FHP showed increased muscle activation, making it difficult to change muscle activity under lower loads, and RSP was correlated with UT activation in shoulder abduction. Therefore, in the RSP, the loaded shoulder abduction is considered a potential risk factor for increasing shoulder muscle tension. This paper proposes an approach to treating RSP before FHP.

• 대한통합의학회지
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• 제11권4호
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• pp.41-50
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• 2023

Purpose : The aim of study was to determine the effect of lower trapezius muscle strengthening exercises on the height of rounded shoulder posture and muscle activity in patients with rounded shoulder posture. Methods : Thirty-one subjects with rounded shoulders were selected and assigned, with the use of a random number table, to an experimental group (EG, n=16) that received resistance exercises of the trapezius (lower) muscles or a control group (CG, n=15) that received isometric exercises of the lower trapezius muscles. In the EG, with the subject in a prone position, both arms were abducted at the angles suggested for each posture (145 °, 45 ° abduction), with the hands holding dumbbells to assume a functional posture. The CG performed only isometric exercises without dumbbells in the same conditions. At the start signal, with the thumb raised, the arm was raised to the level of the ear. Both groups were assessed by the height of the rounded shoulder posture (RSP) and muscle activity (EMG). The intervention was performed three times a week. Results : The RSP significantly decreased during the intervention period in both the EG and CG (p<.05), and a significant difference was determined between the RSP of the two groups (p<.05). In the EG, the EMG significantly increased during the intervention period (p<.05), but the CG did not show any significant increase (p>.05). The final EMG was significantly higher in the EG than in the CG (p<.05). Conclusion : Both the EG and CG showed positive improvement in rounded shoulder posture during the intervention period. In particular, lower trapezius resistance exercise appears to reduce shoulder height and positively affects the activity of muscles around the shoulder.

• 국제물리치료학회지
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• 제6권1호
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• pp.815-823
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• 2015

This study aimed to examine the most effective exercise method for shoulder joint rehabilitation by comparatively observing activity of shoulder stabilizer muscles during push up and push up plus exercises under diverse stable conditions. The subjects were 20 healthy adults students who went to M university. While the subjects conducted push up and push up plus exercises under diverse stable conditions(a stable surface, a support of 25cm height, a support of 30 cm height and a balance pad), activities of the upper trapezius muscle, pectoralis major muscle, serratus anterior muscle, and triceps brachii muscle were recorded. During push up and push up plus exercises, activities of the stabilizer muscles were higher when the stable condition was changed rather than on the stable surface. In particular, when the support of 30cm height and balance pads were applied, activity of the shoulder stabilizer was highest. There were significant differences in the upper trapezius muscle and triceps brachii muscle during the push up exercise(p<.05) and in the serratus anterior muscle during the push up plus exercise(p<.05). Activities of the shoulder stabilizers were higher when the upper and lower limbs' surface stable conditions were changed than the stable surface. Therefore, when programs for rehabilitation of shoulder joints are applied, provision of diverse stable conditions according to patients' conditions will be effective methods.

• Journal of Periodontal and Implant Science
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• 제52권2호
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• pp.170-180
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• 2022

Purpose: This study was conducted to assess the effect of hard and/or soft tissue grafting on immediate implants in a preclinical model. Methods: In 5 mongrel dogs, the distal roots of P2 and P3 were extracted from the maxilla (4 sites in each animal), and immediate implant placement was performed. Each site was randomly assigned to 1 of the following 4 groups: i) gap filling with guided bone regeneration (the GBR group), ii) subepithelial connective tissue grafting (the SCTG group), iii) GBR and SCTG (the GBR/SCTG group), and iv) no further treatment (control). Non-submerged healing was provided for 4 months. Histological and histomorphometric analyses were performed. Results: Peri-implant tissue height and thickness favored the SCTG group (height of periimplant mucosa: 1.14 mm; tissue thickness at the implant shoulder and ±1 mm from the shoulder: 1.14 mm, 0.78 mm, and 1.57 mm, respectively; median value) over the other groups. Bone grafting was not effective at the level of the implant shoulder and on the coronal level of the shoulder. In addition, simultaneous soft and hard tissue augmentation (the GBR/SCTG group) led to a less favorable tissue contour compared to GBR or SCTG alone (height of periimplant mucosa: 3.06 mm; thickness of peri-implant mucosa at the implant shoulder and ±1 mm from the shoulder: 0.72 mm, 0.3 mm, and 1.09 mm, respectively). Conclusion: SCTG tended to have positive effects on the thickness and height of the periimplant mucosa in immediate implant placement. However, simultaneous soft and hard tissue augmentation might not allow a satisfactory tissue contour in cases where the relationship between implant position and neighboring bone housing is unfavorable.