I would be remiss if I did not address the immense controversy surrounding the pullover and what muscles are involved. Many will insist that the pectoral muscles are the primary movers in pullovers, while others may stubbornly argue that the latissimus dorsi is the main muscle recruited. Thus I am providing a breakdown of the exercise in an effort to clear up some of the confusion.
Analysis of the Pullover Exercise
The pullover exercise recruits a number of muscles, making it an excellent movement for balancing out the upper body. During the concentric, or upward phase of the pullover movement, the pectoralis minor is recruited during the initial phase of shoulder extension, followed by recruitment of the sternal fibers of the pectoralis major to assist in progressive extension of the shoulder. Other muscles involved in extension of the shoulder are latissimus dorsi, teres major, posterior deltoid, infraspinatus, teres minor, andsubscapularis. Latissimus dorsi, rhomboids and teres major are also involved in scapular retraction and medial rotation of the humerus during the concentric phase.
EMG measures indicate: The Pullover is a ‘chest exercise‘
There has been some controversy surrounding whether the pullover is primarily a chest or back exercise. A study conducted by Marchetti and Uchida examined the activity of the pectoralis major and latissimus dorsi by means of EMG analysis during the barbell pullover exercise (Marchetti. 2011). It was determined that the pectoralis major was activated to a much greater degree than the latissimus dorsi, and that the higher activation was dependent on the external force lever arm produced. A more heated controversy surrounds the utility of the pullover movement in recruiting the serratus anterior. During the eccentric phase of a pullover, i.e. during the phase in which the weight is being lowered overhead towards the floor, the serratus anterior, intercostal cartilage and intercostal muscles are stretched, triggering hypertrophy.
What is the degree of recruitment of the serratus anterior?
A review of musculoskeletal anatomy reveals that theserratus anterior muscle sweeps over the lateral portions of the intercostal muscles as well as the lateral portion of the ribcage. Serratus anterior fibers also run above the attachments of the latissimus dorsi muscle fibers on the lateral aspects of the first eight ribs. This explains why a well developed serratus anterior contributes to the flare of the lats in a balanced competitive bodybuilder. Another critical attachment of the serratus anterior is to the medial border of the scapula, enabling it to pull the scapula forward and tethering it to the thoracic wall, thus conferring stability to the scapula (preventing scapular winging). However, such winging is prevented by lying supine on or across a bench as is done during a pullover.
In summary, the serratus anterior abducts, upwardly rotates and weakly elevates the scapula. Some will argue that in a pullover movement, the serratus anterior does not contribute greatly to the movement itself, rendering the pullover almost useless in building the serratus fibers. Others will argue that due to the stretch stimulus of the eccentric phase of the pullover, the serratus anterior is strongly activated and responds with appreciable hypertrophy.
Exercise Description: How to Perform DB & BB Pullovers
Dumbbell Pullovers: Lie on bench or across bench (this allows a greater stretch of the ribcage) with feet firmly planted on floor. Hold a dumbbell with both hands, with palms against the underside of the upper end of plates and thumbs crossing over one another around handle. Lower weight behind your head, inhaling as you do so and keeping elbows slightly bent. Then raise dumbbell so that it is directly above you, elbows straight.
Barbell Pullovers: Lie on bench. Extend arms above you and take an overhand grip (palms will be facing upwards) on the barbell with hands
shoulder width apart and elbows straight and in line with arms. Lower weight behind your head, inhaling as you do so. Then raise barbell so that it is directly above you.
Which one do I do? Generally speaking, the dumbbell version tends to afford a better stretch in the chest and ribcage, while the barbell version appears to trigger more lat recruitment. Both versions will cause a stretch and expansion in the ribcage and serve as excellent finishing moves during chest day.
References: Effects of the Pullover Exercise on the Pectoralis Major and Latissimus Dorsi Muscles as Evaluated by EMG. JAppl Biomech, 2011 Nov;27(4):380-4. Marchetti,P.H. and Uchida, M.C.