Pronated Cable Triceps Extension
Unlike the picture this exercise should be done unilaterally. This means one arm at a time using the weaker arm first. Use 10 seconds rest between arms with the same weight load in a majority of cases.
The palm should face the floor during the entire movement. Aim to finish on bottom with your palm traveling behind your hip to maximize the contraction without stressing the elbow.
Do not lean forward to assist with the exercise which stresses the shoulder. Keep the tension on the triceps by using a balanced stance.