Tricep kickbacks are a good way to help develop and strengthen muscles which are otherwise not often incorporated into workouts. The triceps are vitally important to ensuring that the rest of your arm is able to function properly as you exercise. However, many people avoid doing exercises that involve the triceps and therefore put themselves at a greater risk of injury, or limit the ability that they'll have to develop the other muscles in the arm.
Performing tricep kickbacks generally works to strengthen and increase the tricep muscles, though it can help to develop other muscles in the arm as well.
The basic position for the tricep kickback involves a three point positioning on a bench. You should first adjust the exercise bench so that it reaches a good height for you. It shouldn't be too tall; set the bench to approximately level with your knee. Place your right hand flat on the bench and bring your right knee up to rest on the bench as well. The rest of your right leg below the knee can sit on the edge of the bench too. Hold your forearm to your side as you bend down so that your gaze is at the floor and your back is level. The dumbbell should be pointing straight down. This is the basic resting position of the exercise.
In order to continue to develop the exercise, you should then execute the kickback itself. In a single, fluid motion, draw your left forearm back so that your arm is straight and the dumbbell is toward your feet and away from your face. Slowly bring the dumbbell back into position so that it returns to the standard resting position. This constitutes a single repetition of the exercise.
It's especially important that you exercise good discipline for safety while you're doing this exercise, as that can be the difference between a successful workout experience and one that may leave you hurt. Be sure to properly stretch before you begin, and always breathe deeply as you conduct any of the basic exercise motions. While the risk of injuring yourself if you drop the dumbbell is slim, you may still wish to have a spotter there to help ensure that you don't accidentally lose a hold of the dumbbell weight.
There are a number of ways that you can modify this exercise. Consider adding a dumbbell row to it as well. Start the dumbbell close to the ground and pull it up so that your elbow is even with your waist first, then perform the tricep kickback before returning through the entire range of motions and leaving the dumbbell toward the floor. Also, be sure that you switch sides of your body so that you adequately work both arms and both sets of tricep muscles through the use of this particular exercise.