When it comes to the triceps, the long head, located smack-dab on the back of the arm, provides the most muscle mass. And to really hit the long head, you can’t go wrong with dumbbell overhead triceps extensions. Putting your arms up places the greatest
amount of stretch on the triceps long head, because unlike the other two triceps heads, the long one crosses the shoulder joint and attaches to the scapula.
When a muscle is stretched to its fullest length at the start of an exercise, it takes the majority of the load during the exercise. This is why triceps extensions performed with the arms overhead, as in dumbbell overhead triceps extensions, place the most focus on the long head for building maximum triceps mass.
overhead triceps extensions make a great follow-up exercise to close-grip bench presses, when your tri’s aren’t that fatigued yet and you can manage a heavy dumbbell.
FORM AND FUNCTION
The long head of the triceps starts on the scapula (shoulder blade) and crosses the back side of the elbow joint where it converges on the common tendon that it shares with the other two triceps heads and attaches to the ulna (forearm bone). The long head is unique from the other lateral and medial heads, because they start on the humerus (upper-arm bone) and do not cross the shoulder joint like the long head. However, all three work together to cause extension of the arm at the elbow joint.
