The pec deck has the convenience and stability of a machine while the chest press is an old standby. The differences between the two don't end with execution. The pec deck is an isolation exercise, working just one joint, while the bench press is compound, which means it utilizes multiple...
known as the sternal head. The pec minor, a smaller chest muscle that lies under the pec major, and the serratus anterior, muscles along the upper rib cage, assist. But, the move primarily just targets the pectoral muscles.