Özet:

Purpose: The purpose of this study was to evaluate the upper trapezius to middle trapezius muscle activation ratio (UT:MT) during scapular retraction exercises at different shoulder abduction degrees in healthy individuals. Methods: Twenty healthy individuals (10 males, 10 females) participated in this study (age: 22.90±2.84 years). A surface electromyography system (TELEmyo DTS; Noraxon USA, Inc, Scottsdale, AZ) was used to measure the activation levels of the upper trapezius and middle trapezius muscles during scapula retraction exercises. For the scapular retraction exercise, participants were instructed to perform a resisted scapula retraction with an elastic band at each of the following shoulder abduction angles: 0º, 45º, 60º and 90º. A repeated measures of ANOVA was used to determine whether UT:MT ratio differed among scapula retraction exercises. Results: There was significant exercise effect on UT:MT ratio (F(3,57)=7.532, p<0.001). The UT:MT ratio was lower at 0º scapular retraction exercise when compared to 45º (p=0.024), 60º (p=0.031) and 90º (p=0.003) scapular retraction exercises. There was no difference between 45º and 60º (p=0.283), and 60º and 90º (p=1.000) scapular retraction exercises regarding UT:MT ratios. Conclusion: Compared to 45° and 60° of shoulder abduction, UT:MT ratio was greater at 60° and 90° of shoulder abduction. Since UT:MT ratio was lower than one, scapula retraction exercise at or under 90° of shoulder abduction might be suggested for the individuals with shoulder problems.

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