Doing a triceps push-down with a straight bar or a rope works the same muscles, but each has its advantages. The rope attachment enables you to target fibers deep within the triceps and to move through a fuller range of motion when you straighten your wrists at the bottom of the exercise. Various types of bars target muscles from different angles. For example, using a v-bar emphasizes the outer portion of the triceps muscle, while a straight bar puts greater emphasis on the long head.
In a 2011 study sponsored by the American Council on Exercise, the rope push-down was found to be slightly more effective than the bar push-down in targeting the triceps muscles. Neither move was as effective as diamond push-ups, declared the gold-standard exercise for the triceps by the researchers. The rope push-down proved 74 percent as effective as these push-ups in targeting all three heads of the triceps. It put more emphasis on the long head of the muscle as compared to the lateral head. The bar push-down was 67 percent as effective as the push-ups and also put more emphasis on the lateral head. Kickbacks and dips ranked higher than the push-downs and worked the lateral and long heads almost equally.