Acute Effect of Static and Dynamic Stretching on Activation of Scapular Stabilizer Muscles During Pull-Up Movement in Gymnasts

Today, there is a disagreement about the effect of various stretching movements on the performance of athletes. Therefore, the aim of this study was to investigate the acute effect of static and dynamic stretching on muscle activity and co-contraction of scapular stabilizer muscles during pull up in gymnasts.

According to the inclusion and exclusion criteria, 15 professional gymnasts with an age (23.25 ± 2.57), height (170.93 ± 5.88), and weight (64.54 ± 5/06) were selected as research samples and divided into three subgroups (each 5).In the pre-test, subjects performed pull up and muscle activity of serratus anterior, upper trapezius, middle trapezius and lower trapezius muscles was measured using a biometric electromyography device. Then each subgroup performed a different stretching protocol in each session and a post-test was performed similar to the pre-test. Repeated measures analysis of variance, Bonferroni post hoc test and paired t-test were used to test the hypotheses.

The results showed that static and dynamic stretching caused a significant decrease and increase of muscle activity in both concentric and eccentric phases. Also, the results showed that dynamic stretch caused a reduction in co-contraction of the serratus anterior and middle trapezius muscles in both concentric and eccentric phases. In addition, there is a significant difference between the effect of static stretch and dynamic stretch and between dynamic stretch and control on co-contraction of serratus anterior and middle trapezius muscles in two concentric and eccentric phases.

The results showed that the co-contraction of serratus anterior and middle trapezius muscles decreased after using dynamic stretching. Therefore, considering the importance of muscle co-contraction in the occurrence of shoulder joint injuries and in order to prevent injuries in the shoulder joint of gymnasts, it is suggested that coaches and gymnasts should use dynamic stretching exercises more carefully.