It has been recommended to use push-up for strengthening the scapular stabilizers and to use unstable surfaces for increasing the neuromuscular system involvement. However, the effect of this instability on the electromyography activity of the periscapular muscles during push-up in individuals with Scapular dyskinesis is not clear. Thus, the present study aimed to determine the effect of unstable surfaces on the electromyography activity of trapezius and Serratus anterior muscles in individuals with scapular dyskinesis during push-up.
A systematic search was conducted in Web of Science, PubMed, and Scopus databases without time limit for start date until September 25, 2021. Using the search strategy, 5,249 articles were identified using the three main keyword categories, including Scapular dyskinesis, electromyography, and push-up. After reviewing the full text of the articles, four studies were included in the final review. Data extraction and methodological quality evaluation were conducted. For meta-analysis, the SMD and the 95% CI were obtained using CMA Software, Ver.3. P-value smaller than 0.05 was considered statistically significant.
According to the results, the use of unstable surfaces in individuals with scapular dyskinesis caused an increase in the activity of the upper trapezius (P= 0.011; SMD= 0.807 [95%CI 0.188, 1.427]) and a reduction in the activity of the Serratus anterior (P= 0.000; SMD= -0.665 [95%CI -1.023, -0.307]). However, it did not significantly affect the electromyography activity of the Lower trapezius (P= 0.176).
Unstable surfaces should be used with higher caution in individuals with scapular dyskinesis because these people have an imbalance of the upper trapezius muscle compared to the serratus anterior muscle and incorrect use of unstable surfaces can cause exacerbation of muscle imbalance in these individuals.