Take the position in dip machine (gravitron machine). Keep your back straight. Adjust the weight in a gravitron machine. Hold machine handles tightly with the shoulder-width grip. Palms are parallel to each other. Hold your body at arms length in gravitron machine. This the movement should only occur at the shoulder joint. your starting position.
Do not extend your elbows to the side, try to hold them close to the body to focus on triceps and do not use chest muscles. Bend your elbows at a 90-degree angle or lower.
Exhaling, pull up with your arms and slowly return back to the starting position. Your body pushes up in gravitron machine. When moving down, pull your shoulder blades together and your shoulders back.
At the bottom of the movement, hold for a few seconds to save tension in bent arms and ensure full contraction in triceps.