• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.914-924
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• 2018

The purpose of this study is to provide the basic data for the shoulder strengthening exercise by analyzing the% MVIC of the muscle activity in the shoulder rotator cuff by the difference of the stance posture and the anatomical plane. 8male subjects were randomly assigned to perform the shoulder rotation exercise 10 times on the frontal plane, the horizontal plane, the sagittal plane and the two legs stance posture, the one leg stance posture, the lunge posture. Measured muscle activity of supraspinatus, infraspinatus, teres minor, anterior deltoid, rectus abdominis, erector supinea, pectoralis major, lattisimus dorsi during exercise. A repetitive one-way ANOVA was performed using the SPSS 22.0 statistical program. First, during the external rotation on the frontal plane, the erector spinea was higher in the lunge posture than in the two legs stance posture and the one leg stance posture, And during the internal rotation on the frontal plane, the muscle activity of suprapinatus was higher in one leg stance posture than in the two legs stance posture and more so in the lunge posture. Second, during the external rotation on the horizontal plane, the muscle activity of deltoid anterior was higher in the one legs stance posture and in the lunge posture than in the two legs stance posture, and during the internal rotation on the horizontal plane, the muscle activity of infraspinatus was higher in the lunge posture than in the two legs stance posture and one leg posture, and the muscle activity of pectoralis major was higher in two leg stance posture than in the one legs stance posture and more so in the lunge posture. Third, during the external rotation on the sagittal plane, muscle activity of rectus abdominis was higher one leg stance posture in the lunge posture than in two leg stance posture. During the internal rotation on the sagittal plane, muscle activity of supraspinatus was higher one leg stance posture in the lunge posture than in two leg stance posture. And muscle activity of infraspinatus was higher in the lunge posture than in two leg stance posture, one leg stance. And muscle activity of Rectus abdominis was higher in the lunge posture and one leg stance posture than in the two legs stance posture. And muscle activity of Erector spinea was higher in the two legs stance postur and lunge posture than in the one leg stance posture. In conclusion, the differences in stance and shoulder anatomy have different effects on the muscle activity of the shoulder rotator exercises, and this is expected to be a more positive exercise program when applied to the shoulder strengthening exercise program.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.105-110
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• 2011

Purpose: The purpose of this article is to identify and understand the complications of RTSA and to review the current methods of preventing and treating this malady. Materials and Methods: Previous constrained prostheses (ball-and-socket or reverse ball-and-socket designs) have failed because their center of rotation remained lateral to the scapula, which has limited of the motion of the prostheses and produced excessive torque on the glenoid component, and this leads to early loosening. The Grammont reverse prosthesis imposes a new biomechanical environment for the deltoid muscle to act, thus allowing it to compensate for the deficient rotator cuff muscles. Results: The clinical experience does live up to the lofty biomechanical concept and expectations: the reverse prosthesis restores active elevation above $90^{\circ}$ in patients with a cuff-deficient shoulder. However, external rotation often remains limited and particularly in patients with an absent or fat-infiltrated teres minor. Internal rotation is also rarely restored after a reverse prosthesis. Failure to restore sufficient tension in the deltoid may result in prosthetic instability. Conclusion: Finally, surgeons must be aware that the results are less predictable and the complication/revision rates are higher in revision surgery than that in the first surgery. A standardized monitoring tool that has clear definitions and assessment instructions is surely needed to document and then prevent complications after revision surgery.