• Journal of the Ergonomics Society of Korea
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• v.18 no.1
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• pp.91-108
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• 1999

In our previous work using a motion analyzer and 3-dimensional sonic digitizer, the arm shapes for 23 women in their early twenties were classified into three characteristic types. In order to design sleeves, suitable for arm movements for the three characteristic arm shapes, a relationship between arm length variation and shoulder/elbow angles has been investigated for four cases of arm movements (flexion, extension, adduction and abduction). Each arm movement can be characterized by the changes in shoulder angle and the changes in elbow angle at the maximal shoulder angle. In all the four cases of arm movements, the changes of shoulder length and cap height are largest at the maximal shoulder angle. These changes were little affected by changes in elbow angle. The changes in the lower arm length and the difference between cap height and upper arm length are the largest at the maximal elbow angle of the maximal shoulder angle. There is a linear relationship between cap height and shoulder angle during arm movements; thus, in designing sleeves the cap height can be determined from the regression of cap height vs. shoulder angle.

• Journal of the Ergonomics Society of Korea
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• v.16 no.3
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• pp.11-21
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• 1997

The purpose of this study is to obtain 3-dimensional isocomfort workspace using the robot kinematics, which is based on perceived discomfort in varying postures for manipulating four types of controls. Fifteen healthy male subjects participated in the experiment where their perceived discomfort in the given postures was measured, in which L32 orthogonal array was adopted. The shoulder flexion and adduction-abduction, elbow flexion, types of controls, and right/left hands were selected as experimental variables. The results showed that the shoulder flexion and adduction-abduction, elbow flexion, and types of controls significantly affected the perceived discomfort at .alpha. =0.01. Depending upon the types of control used, regression equations predicting perceived dis- comfort and three dimensional isocomfort workspace were suggested based on the experiemntal cata. Using the equations, driver's isocomfort workspace in his/her cabin for pushing operation was illustrated, in which the robot kinematics was employed to describe the translational relationships between the upper arm and the lower arm/hand. It was ecpected that isocomfort workspace could be used as a valuable guideline to design workplaces ergonomically.

• The Korean journal of sports medicine
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• v.36 no.4
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• pp.173-179
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• 2018

A variety of theories have been reported as causes of shoulder pain in overhead throwing athletes. Recently, an explanation with microinstability of the shoulder and internal impingement has been proposed. The concept of the microinstability is that pathologic laxity of the anterior capsule caused by repeated abduction and external rotation of the shoulder leads to abnormal glenohumeral biomechanics and causes internal impingement of the shoulder. Based on the understanding of the pathology, it is recommended to identify the causes of shoulder pain in the overhead throwing athletes and perform appropriate rehabilitation or surgical treatment.

• Physical Therapy Rehabilitation Science
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• v.6 no.4
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• pp.208-213
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• 2017

Objective: Despite reliable evidence of abnormal scapular motions increases, there is not yet sufficient evidence of abnormal humeral translations. This study aims to analyze the motion of the humeral head toward the scapula when the shoulder is actively abducted using the C-arm. Design: A case report. Methods: The participant was a healthy man without any limitation and pain during shoulder movement. The participant's shoulder was abducted; this movement in the frontal plane was measured using a C-arm (anterior-posterior view) and was analyzed with computer-aided design. The starting posture was $15^{\circ}$, and as the participant abducted his shoulder measurements were taken and analyzed at $30^{\circ}$, $60^{\circ}$, $90^{\circ}$, $120^{\circ}$, $150^{\circ}$, and ending at $165^{\circ}$. A line was drawn perpendicularly to the line connecting the humeral head axis to the glenoid, and another line was drawn perpendiculary to the line connecting the scapular axis to the glenoid. The distance between the two lines measured is defined as the e value. Results: At the starting posture ($15^{\circ}$), the central axis of the humeral head was located 1.92 mm inferior to the central axis of the scapula. The humeral head was superiorly translated from the starting posture to $120^{\circ}$, and then, showed an inferior translation to the ending posture ($165^{\circ}$). Conclusions: The results of this study showed that the humeral head moved upward from the starting posture ($15^{\circ}$) up to $120^{\circ}$ indicating, superior translation, and it moved downward when the posture was past $120^{\circ}$, indicating inferior translation.

• Clinics in Shoulder and Elbow
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• v.7 no.1
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• pp.41-45
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• 2004

In adhesive capsulitis of the shoulder of no response to nonoperative treatment, an arthroscopic capsular release and manipulation improves range of motion and pain relief. We performed an arthroscopic examination in the stiff shoulder, of which she had no response to nonoperative treatment, after the conservative treatment of a clavicular shaft fracture by motorcycle-driver traffic accident. We found the intra-articular 'rotator interval bridging scar adhesion' between subscapularis tendon and antero-superior glenoid fossa under the rotator interval which was no adhesion and contracture itself. We performed the scar adhesion removal and synovectomy, maintaining the rotator interval. We recommended nonsteroidal anti-inflammatory drug for postoperative pain relief and continuous active and passive range of motion (ROM) exercise to gain motions. Preoperatively, active and passive range of motion were 70° for forward elevation, 60° for abduction and especially 0° for external rotation. After postoperative 2 months, active ROM were 150° for forward elevation, 130° for abduction and 80° for external rotation. After postoperative 6 months, passive and active ROM were full. UCLA score improved from preoperative 9 points to postoperative 29 points.

• Clinics in Shoulder and Elbow
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• v.4 no.2
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• pp.166-172
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• 2001

Purpose: To evaluate effectiveness of arthroscopic capsular release combined with manipulation in frozen shoulder. Material and Method: 15 patient who had failed to respond to physical therapy were evaluated, which were treated with arthroscopic capsular release combined with manipulation, from July 1998 to March 2000. Result: At a mean of fifteen months(range, six to twenty four) after the combined procedure, the improvement in the score of Constant and Murley averaged 45 points. The mean improvement in motion was 76 degrees for abduction; 40 degrees and 65 degrees for external rotation in adduction and abduction. Conclusion : Arthroscopic capsular release with manipulation is useful method to treatment the frozen shoulder which was not respond to conservative treatment.

• Clinics in Shoulder and Elbow
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• v.25 no.4
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• pp.265-273
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• 2022

Background: Massive rotator cuff tears (MRCTs) with subscapularis (SSC) tears cause severe shoulder dysfunction. In the present study, the influence of SSC tears on three-dimensional (3D) shoulder kinematics during scapular plane abduction in patients with MRCTs was examined. Methods: This study included 15 patients who were divided into two groups: supraspinatus (SSP) and infraspinatus (ISP) tears with SSC tear (torn SSC group: 10 shoulders) or without SSC tear (intact SSC group: 5 shoulders). Single-plane fluoroscopic images during scapular plane elevation and computed tomography (CT)-derived 3D bone models were matched to the fluoroscopic images using two-dimensional (2D)/3D registration techniques. Changes in 3D kinematic results were compared. Results: The humeral head center at the beginning of arm elevation was significantly higher in the torn SSC group than in the intact SSC group (1.8±3.4 mm vs. -1.1±1.6 mm, p<0.05). In the torn SSC group, the center of the humeral head migrated superiorly, then significantly downward at 60° arm elevation (p<0.05). In the intact SSC group, significant difference was not observed in the superior-inferior translation of the humeral head between the elevation angles. Conclusions: In cases of MRCTs with a torn SSC, the center of the humeral head showed a superior translation at the initial phase of scapular plane abduction followed by inferior translation. These findings indicate the SSC muscle plays an important role in determining the dynamic stability of the glenohumeral joint in a superior-inferior direction in patients with MRCTs.

• The Journal of Korean Physical Therapy
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• v.15 no.3
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• pp.223-238
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• 2003

The purpose of this study was to assess the effectiveness of taping therapy for adhesive capsulitis patients. The subjects were consisted of 40, male 18, female 22, average age was 59 years old. To find out the effectiveness of taping therapy, we sampled 20 patients treated with H/P, electrical therapy and scapular pattern & hold-relax technique of PNF(control group), and 20 patients treated same as control group with taping therapy(experimental group). The results were as follow : 1. There was a statistical significance of shoulder flexion, abduction, external rotation and VAS in both group(P<0.05). 2. There was not statistical significance of shoulder flexion and external rotation(P>0.05), but abduction had a statistical significance between taping group and non-taping group(P<0.05). 3. VAS was observed a statistical significance between 3rd and 4th post treatment(P<0.05). These results are imply that taping therapy has a effectiveness of shoulder motion and VAS for adhesive capsulitis.

• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.95-105
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• 2000

Glenohumeral internal and external rotation with shoulder abducted in the frontal plane often causes impingement of the supraspinatus tendon. whereas similar activity in scapular plane does not cause impingement. The Purpose of this study was to determine if assessment among the three positions as 30 degrees, 60 degrees, 90 degrees abduction in the sitting position of the scapular plane could be affected the comparison between intemal and external peak torque, total work, average power. In this study, Isokinetic shoulder rotational strength was evaluated in twenty healthy male university students, using the Cybex NORMTM System (CYBEX Division of LUMEX, Inc., Ronkonkoma, New York). Test data was gathered in the plane of the scapular, 30 degrees of horizontal flexion anterior to coronal plane, and the subjects performed the test with the arm 30, 60, and 90degrees abducted in the sitting position. also, test speed was set at deg/sec. Statistical analysis was performed using SPSS 7.5 for Windows software and mean and standard deviations were calculated. ANOVA was used to analyze the difference of the values in the three test positions. A paired t-test was used of examining the difference in the means peak torque between external and internal rotation. Not any significant difference was found among three abduction positions in scapular plane, even though there was a consistent pattern of greater strength in the abducted position of 60 degrees. Internal relation strength peak torque and total work were greater than those of external rotation in every test positions.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.93-99
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• 1998

We measured the glenohumeral and scapulothoracic movements during abduction of the arm in the coronal plane with radiologic analysis in the 30 shoulders of normal male adults who were without pain, limitation of motion, and history of trauma. In the resting position, the glenoid cavity of the scapula faced somewhat superiorly in over 80 percents of the individuals, the mean superior tilting was 5.7 degrees. The mean total scapulothoracic movement was 65.8 degrees and the mean total glenohumeral movement was 106.8 degrees during abduction of arm in the coronal plane. The mean ratio of the glenohumeral movement to the scapulothoracic movement was 1.6 and this GH/ST ratio was decreased toward the extreme abduction. When the arm was abducted, external rotation of the humeral head occurred and this external rotation was increased smoothly during 0 degree through 90 degrees, but steeply above 90 degrees. The acromiohumeral interval was 10.9 mm at the resting positon, and this interval decreased during the arm abduction. The superior migration of the humeral head was 3.1 mm while abducting the arm. Our measurement of the relationships of glenohumeral and scapulothoracic movements at the coronal plane would be useful in the understandings of the biomechanics of shoulder, but further study would be required for the analysis of the three dimensional relationship because of the limitation of our two dimensional analysis.