There are three muscles that make up the triceps: the long head, medial head, and lateral head. This exercise is going to emphasize the long head. In fact, any time the arm is extended from a raised position, the long head is emphasized. The function of the triceps is to extend the elbow. So any time you push a door closed, throw a ball, or put something away in a cabinet, your triceps are involved. Here is how the exercise is done:

First, ensure that the cable pulley unit is adjusted up high. Use the handle attachment to connect to the cable. Grab the handle and face in the opposite direction of the machine. Lunge forward on one leg and position your elbow parallel to the floor. Next, extend the elbow until the arm is straight. Slowly return to the starting position. The key to this exercise is to minimize the movement of the elbow.