from a site called preventdisease:
"DUMBBELL PULLOVERS
Prime Mover: lats and triceps
Secondary Movers: pecs
Now here's an exercise with problems!
Pullovers are supposed to ``expand the rib cage." This assumes that ribs will somehow lengthen, or that cartilage will change to allow expansion to take place. Bone just doesn't work that way.
Training of various types can change the vital capacity of the lungsâthe quantity of air that can be exhaled by the fullest expiration after making the deepest inspiration. However, much of this change results from the learned ability to use available lung space and from improved control of the diaphragm. Neither factor translates into a larger rib cage. Despite the tremendous vital capacities of opera singers and trumpet players, for instance, they, as a group, still possess normal sized rib cages.
Pullovers won't expand your rib cage; but there's a good chance that, in time, doing them will cause shoulder or other injuries. One example: The exercise can stretch the connective tissue that forms the vertical ``midline" between the abdominals. If that tissue tears, you have a hernia of the median rectus, which produces a slight bulge in the center of your abs that increases in size when you strain. A hernia of the median rectus is of little clinical significance, but it's certainly not what you were trying to develop! (If you have such a bulge in the center of your abs, don't attempt to diagnose it yourself. Several conditions could be responsible.) Pullovers also put tremendous stress on the posterior aspect of the shoulder; even before you sustain a clinical injury, they can cause a great deal of pain.
The bottom line: Pullovers won't enlarge your ribcage, and their high potential to injure the rotator cuff and other structures far outweighs whatever minimal muscular gains they may promote.
UPRIGHT ROWS
Prime Mover: lateral and anterior delt
Secondary Mover: upper trapezius
One exercise you should eliminate from your weight training program is the Upright Row. This exercise places the shoulder in internal rotation as the arm is raised, a position that does not allow sufficient space for the greater tubercle to clear the acromion.
Supposed ``proper form" requires pulling the elbows as high as possible. This simply increases the degree of internal rotation and magnifies the danger of impingement.
The onset of pain from Upright Rows often is not immediate, although it may be. Usually the inflammation in the tendons and bursae increases with shoulder motion after the workout is over. Pain may develop hours or days later, making it difficult to associate the pain with a particular exercise. People with this inflammation usually feel pain during any stressful shoulder exercise âsuch as Bench Presses, Incline Presses, Behind-the-Neck Presses, Behind-the-Neck Pull downs, Pullovers, and Military Presses.
Upright Rows accelerate rotator cuff degeneration. If you do them, you risk developing chronic tendonitis or bursitis."