The push-up is a fantastic exercise for the chest, shoulders and triceps. These simple bars are excellent tools to improve the form of your push-ups. The standard push-up, where you place your palms flat on the ground, has been known to cause severe wrist injury, due to the amount of stress placed on the wrists in a hyperextended position (a very unnatural position for your wrists). However using these bars there is no danger of this, as the grip you use on the bars is a much stronger and more comfortable position for your wrists. With these bars you can work on the most important part of the exercise - slowly lowering yourself all the way down to the ground (aim for 2-3 seconds). Tightening your grip on the bars can also help build strength in the forearms as well, which isn't possible with your hands flat on the floor.
If you're using the bars properly, you'll likely find that to begin with you won't be able to do as many push-ups reps with the bars as you would without them. This is because you are doing the push-up with proper form - the most effective way to build strength and muscle.
These bars are cheap and very effective - a must have!