(29) DIFFERENCES IN MUSCLE ACTIVATION BETWEEN THE TRADITIONAL AND SWISS BARBELLS DURING THE BENCH PRESS EXERCISE

Introduction: Exercise selection is a critical component of resistance training program design. The bench press exercise is commonly used to enhance strength and hypertrophy in the upper body musculature. The bench press is typically performed using a traditional barbell (TB); however, the Swiss barbell (SB) could be an appealing alternative due to a neutral grip, allowing for a more sport-specific movement. Furthermore, a neutral grip may be a better option for individuals with limited shoulder mobility. It is unclear, however, whether muscle recruitment patterns differ when performing the bench press using a TB vs. a SB.  This understanding could improve training specificity when selecting upper-body exercises.

Purpose: To compare the magnitude of muscle activation elicited during the bench press exercise when using a TB vs. SB.

Methods: Nine, college-aged males (stature 1.78±0.06 m; body mass 87.45±13.41 kg) were recruited and screened for cardiovascular and musculoskeletal impairment that could be exacerbated by testing. All participants were experienced in resistance training, defined as lifting weights for ≥ 2 days/week for ≥ 1 year. In addition, participants were required to bench press ≥ 75% of their body mass using a TB. Participants visited the laboratory on three occasions separated by ≥ 48 hours, with all sessions completed within 10 days. The first two sessions were counterbalanced and consisted of one repetition maximum testing (1RM) with the TB or SB. In the final session, participants performed a maximal voluntary isometric contraction (MVIC) consisting of a maximal TB press against pins for three seconds. Following MVIC, two sets of three repetitions of the bench press were performed with each barbell in the same counterbalanced order. The first set was performed at 65% and the second set at 85% of 1RM with each barbell, respectively. Muscle activation was assessed via surface electromyography (EMG). Following skin preparation, electrodes were attached to the sternal head of the pectoralis major, anterior deltoid, the medial and lateral heads of the triceps brachii, and latissimus dorsi. Raw EMG signals were collected at 2000 Hz (high and low pass filter cutoffs 10-500 Hz, respectively) by an Ultium EMG unit (Noraxon USA Inc, Scottsdale, AZ). The EMG signal from the concentric portion of each repetition was rectified, smoothed (by root mean square algorithm with a 100 ms window), and normalized relative to the MVIC. A 2x2 repeated measures analysis of variance (ANOVA) was used to analyze the changes in muscle activation across intensities and barbells.

Results: No statistically significant main effects were found for barbell type (p>0.05), but there was a statistically significant main effect of intensity for the anterior deltoid (p=0.01), medial head of the triceps brachii (p=0.004), lateral head of the triceps brachii (p=0.003), and latissimus dorsi (p=0.043). No significant interaction effects of barbell type and intensity were observed for any muscle (p>0.05).

Conclusions: The current findings suggest that the magnitude of muscle activation was not different between TB and SB when performing the bench press exercise. PRACTICAL APPLICATIONS: Strength and conditioning professionals may consider the use of the SB when the primary goal is to mimic a sport-specific movement, or when shoulder mobility is limited, without compromising muscular activation or potential adaptation during the bench press exercise.

Acknowledgements: None