All sorts of exercises for the development of deltas (the shoulder, in fact, is the part of the arm from the delta to the elbow, and the deltoid muscle – this is the same ball of three bundles that you want to develop) is a great many. You can work with blocks, with dumbbells, with a barbell, not to mention dozens of specialized simulators.
Below I will give the most effective movements in my personal opinion, which is not the ultimate truth. It was these movements that I used to study the deltas to their current state.
First, a little theory. The delta consists of three head. Front, middle and rear. The front is responsible for pushing movements, the rear – for pulling. The middle delta is partly involved in both cases, plus when moving the arms to the sides.
Army bench press (standing bench press)
An excellent basic exercise for the development of the anterior delta, which partly involves the middle beam too. The width of the grip is average, that is, take the bar slightly wider than the shoulders. Take it too wide – part of the load will be stolen by the chest, too narrow – overload the triceps, which will fail before the delta works well.
My personal advice – I do not recommend lowering the bar below the level of the chin so as not to give a breaking load on the joint. Even if flexibility allows you to lower the barbell on your chest, you should not tempt fate. The risk of injury does not at all justify the additional stretching of the muscle for its supposedly better growth.
Please note that the army bench also works out well for core muscles.
Dumbbell Bench Sitting or Standing
An alternative to the army bench press, if you do a bench press dumbbell. In the case when there is difficulty with the lower back and a large compression load is undesirable, you can do a dumbbell bench press sitting with a slight tilt of the bench (80 °).
Of the features, I note only the moment where it is necessary to lower the dumbbells – to the level of the ears or so that the angle between the shoulder and forearm is 90 °. Lower it below – create a breaking load on the shoulder joint. Also do not forget that the dumbbells lie on the base of the palms