They reported that the biceps
brachii displayed significantly greater muscle activity
during the dumbbell
bench press, while the barbell
bench press displayed significantly greater activity than the smith machine.
Comparing four different angles of the
bench used
during the narrow grip
bench press, Barnett et al. (1995) found a main difference in triceps
brachii muscle activity between -18 degrees and 0 (flat) compared with 40 and 90 degrees.