A comparison of EMG fluctuation of deltoid and pectoralis major muscles in bench press

Abstract

The purpose of this study was to compare the EMG fluctuation of pectoralis major-clavicular portion (PMC) and deltoid-anterior portion (DA) muscles executions of bench press with barbell and dumbbell. Fifteen male healthy employees (mean ± SD; age 30.13 ± 5.33 years; hewight 175.33 ± 6.07 cm; weight 69.80 ± 12.14 kg) without previous injuries of elbow and shoulder joints, DA and PMC muscles, volunteered to participate in the study. Surface electromyography data (AEMG and MPF) were recorded and calculated for PMC and DA muscles of dominant hand, during execution of bench press with both barbell and dumbbell exercise. Subjects performed 10 trials of bench press within 20 seconds. Results showed no significant difference between two execution of bench press with barbell and dumbbell over EMG fluctuation of PMC and DA muscles (P ≤ 0.05). However when EMG fluctuation of PMC and DA muscles were compared with each other, a significant difference was found (P≤0.05), but in both exercise executions the EMG activity of DA was higher than PMC. The results of this study indicated that two execution of bench press with barbell and dumbbell are equally efficient in strengthening the PMC and DA muscles because the posture adapted for elevation with hand dumbbells is essentially the same one observed for elevation with barbell. Otherwise the EMG activity of DA was higher than PMC, because PMC showed abrupt activity to surpass the limb inertia and weight against the gravity action at the initial position but it was found similar behavior for DA in all phase of movement.