Stand, facing cable, in good body alignment (abs tight, chest up, back straight) with feet in comfortable position. Grip bar (palms down) and position upper arms perpendicular to the floor with elbows bent at 90 degrees. Keeping back straight, slightly bend forward. In a controlled motion, keeping upper arm perpendicular to the floor, push bar down, until arms are approximately straight. Contract triceps fully, without compromising form. While maintaining the controlled motion, return bar to starting position. Do not allow muscles to relax before next repetition.
Here are a few suggested alternative exercises:Ball Band French CurlBall Band Triceps KickBackBand KickBacksBand Overhead ExtensionBand Tricep ExtensionClose Grip Bench Press - BarbellClose Grip Dumbbell PressDecline Dumbbell Close GripDips - MachineDumbbell Lying ExtensionTricep Extension - Hammer Strength