مقایسه فعالیت الکتریکی عضلات دندانه‌ای قدامی و ذوزنقه فوقانی و وضعیت تقارن کتف بین سه رشته تیراندازی

Objective: The purpose of the present study was to compare the serratus anterior and upper trapezius muscles activities in the shoulder abduction and scapula symmetry position in three shooting fields including archery, pistol and air rifle. Methods: Twenty&shy;-four available shooters between 20 to 40 years old with more than 3 years of professional training history participated in this study. The electrical activity of muscles during 60 and 90 degree abduction with dominant hand were evaluated using surface electromyography in scapular symmetry position by using Modified Lateral Scapular Slide test. Data were analyzed through independent samples t-test and ANOVA. Results: In both 60 and 90 degree abduction positions, the activity of the serratus anterior muscle in archery group was significantly more than those in the pistol and air rifle positions (P< 0.05). However, the activity of the upper trapezius muscle did not indicate any significant difference in the three groups (P> 0.05). There were significant differences between distances of two lower scapular angles from the vertebral column in positioning of the hand on the hip in air rifle, and in positioning of the hand in 90 degree elevation, in archery and pistol groups (P< 0.05). Also there were significant differences in the scapular symmetry in positioning of the hand on the hip, and in 90 degree elevation, between archery and rifle groups, and between rifle and pistol groups (P< 0.05). Conclusion: The different positioning of hand and shoulder in different shooting fields as the dominant postures during exercises and competitions, can be one of the most important causes of the difference in muscles electrical activity and scapular symmetry among these groups.