The tricep kickback should be performed as follows:
1.) Begin with one hand and one knee on the bench and the opposite foot flat on the floor
2.) Hold a dumbbell in the hand that is not on the bench, row your elbow up till your elbow is at a 90 degree angle. Kick your forearm backwards to straighten your arm and return to the 90 degree angle.
3.) Repeat this action using the muscle in the back of your arm. Perform 2 to 3 sets of 10 to 12 reps on each arm for the best results.