The investigation of bilateral deficit and surface electromyography recordings regarding single and multiple isometric contractions of athletes in different sports branches

The purpose of this research is to determine the changes in the strength performances, bilateral deficit, and EMG activities of the athletes in the maximum isometric contractions in different measurements as single and multiple. A total of 20 healthy male athletes, including 5 football, 5 volleyball, 5 handball and 5 wrestling, who did not have any health problems and played elite-level sports, comprised the research group. The "Informed Consent Form" was signed by the athletes participating in the study, and verbal information was also provided about the practices to be made by the researcher. Primarily, in line with the research method, height, weight, and body fat percentage measurements of the athletes were made. Then, strength and electromyography activity determinations of Unilateral, Bilateral Independent, Bilateral Common, Ipsilateral, Bilateral, and Ipsilateral measurements were made in flexion and extension movements of elbow and knee joints. Shapiro Wilk Test was applied to the obtained data as a normality test. In addition, by looking at the kurtosis, skewness values and histograms, it was seen that the data had a normal distribution. Independent Sample T-Test was used for bilateral comparisons, and ANOVA Test for Repeated Measurements was used to determine the differences between measurements. The measurements found to be significant were determined using the Adjustable Bonferroni Test. All analyses were based on α=0.05 significance level. In the analysis made, it was seen that there was a significant difference in the Strength and EMG activities of single and multiple maximum isometric contractions. As a result, it was determined that the majority of the research group showed Bilateral Deficit (BLD). In addition, it was found that higher strength performance and EMG activity were recorded in the Uni maximum isometric measurements of the athletes compared to other measurements (Bi-B, Bi-O, İpsi, Bi+İpsi).