The long head like all the other triceps, is biased by doing elbow extension when the shoulder is also in alignment. This is in the scapular plane with shoulder extension for the short position and shoulder flexion for the lengthened position.
Like anything in this industry, there’s people with different opinions on things. Of what little longitudinal studies we do have on hypertrophy comparing triceps exercises, which there isn’t much, there is a small bias towards lengthened exercises being be slightly more hypertrophic, or at worst equally so.
Regardless of where you sit on that item of debate, here are two options you can use to bias a bit more long head, or just have as extra tools in your training toolbox. Remember, the worst case scenario if the opposing argument against using biased exercises were true, is these exercises are equally effective. And remember, no exercises are a must.
Learn more about exercise analysis, setup, and selection in our Biomechanics Course
Learn how to apply your biomechanical knowledge to writing workouts with our Program Design Course