Comparative Evaluation Of Strength And Electrical Activity Of The Pectoralis Major Muscle During Bench Press Exercise In Horizontal, Incline And Decline Modalities

Abstract

Introduction: The sports have great meanings in adult health. The contributions of the practices of physical exercise has been huge. Objective: The aim of this study was to evaluate the strength and the electrical activity of the pectoralis major muscle during bench press exercise on a machine in horizontal, incline and decline positions. Methodology : The sample was constituted of 20 male subjects with mean age of 23.2 ± 0.9 years old. They underwent electromyographic evaluation of the three parts of the pectoralis major muscle, performing the horizontal bench press exercise with or without lumbar rectification, and they also performed the incline and decline modalities. The exercises consisted of three repetitions with Maximal Voluntary Isometric Contraction (MVIC) lasting 5 seconds each, with one-minute interval between them, followed by verbal commands of the researcher. The muscle strength values expressed in kilograms (kg) were analyzed using Miograph 2.0 software and the electromyographic signal was normalized by MVIC and extracted from a three-second window. Inferential statistics was applied by Friedman and Multiple Comparisons non-parametric tests (p<0.05). Results: The electrical activity of the clavicular and sternocostal parts of the pectoralis major muscle showed no significant difference between the four modalities of bench press exercises. However, the electrical activity of the lower part in the incline bench press exercise was statistically lower compared with the other modalities. Muscle strength was not significantly different between the four modalities of bench press exercise. Conclusion: In conclusion, muscle strength and electrical activity of the pectoralis major muscle showed no differences between the bench press modalities, except for the electrical activity of the lower part in incline exercise.