The barbell pullover is a popular exercise used to improve upper body muscle mass and strength.
However, it has not been established which of the involved muscles is the prime mover. Recently, researchers from Brazil have filled this gap in the literature.
The prime movement of the pullover exercise is shoulder extension.
The chest (mainly the pectoralis major) and back (mainly the latissimus dorsi) are the major acting muscles during the movement. However, which of these muscles is most active during the exercise has not been established.
The researchers recruited eight healthy males to perform the barbell pullover exercise.
The exercise was performed on a bench, hands were positioned at shoulder width and the arms were remained straight throughout the exercise. The set up can be seen in the picture below.
The exercise was performed for 10 reps, with a weight that was 30% of the subject’s bodyweight.
The researchers attached electrodes to the chest and back muscles to measure EMG. EMG measures the electrical potential generated by muscle cells and is a marker for muscle activity.
The researchers found that the muscle activity of the pectoralis major showed a much higher activity than the latisimus dorsi.
The reseachers conclude that the pullover exercise should be primarily classified as a chest exercise.
Most chest exercises consist of horizontal adduction at the shoulder (e.g. bench press, fly, and cross over). Therefore, they suggest that the pullover, which is characterized by shoulder extension, might be a useful addition to a chest workout.
Source: J Appl Biomech. 2011 Oct 4.