There is also a special null type, the type of the expression null, which has no name. Because the null type has no name, it is impossible to declare a variable of the null type or to cast to the null type. The null reference is the only possible value of an expression of null type.
The military barbell press mainly works the shoulder, or deltoid, muscles. The anterior deltoid, the front head of the shoulder muscle, does much of the work. The side, or lateral, deltoid and the rear, or posterior, deltoid are also involved in the movement, although to a lesser degree than the anterior deltoid.
Primary Muscles. The main muscle targeted by the dumbbell shoulder press is the anterior deltoid, or the front shoulder. To a slightly lesser degree, the exercise also hits the remaining deltoid muscles, including the lateral deltoid, or the outside of your shoulder, and posterior deltoid, or the back of your shoulder.