Effect of Five Bench Inclinations on the Electromyographic Activity of the Pectoralis Major, Anterior Deltoid, and Triceps Brachii during the Bench Press Exercise

The bench press exercise is one of the most used for training and for evaluating upper-body strength. The aim of the current study was to evaluate the electromyographic (EMG) activity levels of the pectoralis major (PM) in its three portions (upper portion, PMUP, middle portion, PMMP, and lower portion, PMLP), the anterior deltoid (AD), and the triceps brachii (TB) medial head during the bench press exercise at five bench angles (0 degrees, 15 degrees, 30 degrees, 45 degrees, and 60 degrees). Thirty trained adults participated in the study. The EMG activity of the muscles was recorded at the aforementioned inclinations at 60% of one-repetition maximum (1RM). The results showed that the maximal EMG activity for PMUP occurred at a bench inclination of 30 degrees. PMMP and PMLP showed higher EMG activity at a 0 degrees bench inclination. AD had the highest EMG activity at 60 degrees. TB showed similar EMG activities at all bench inclinations. In conclusion, the horizontal bench press produces similar electromyographic activities for the pectoralis major and the anterior deltoid. An inclination of 30 degrees produces greater activation of the upper portion of the pectoralis major. Inclinations greater than 45 degrees produce significantly higher activation of the anterior deltoid and decrease the muscular performance of the pectoralis major.