Dumbbell Shoulder Press

Dumbbell shoulder press execution

1
Focus on the elbows and push them straight upward until they pass shoulder height. The arms are almost straight at the end of the movement. The dumbbells move toward each other but do not touch.
2
Lower your arms back in a controlled manner until the dumbbells are level with the ears.
3
Repeat.

Dumbbell shoulder press

Muscles involved:

Shoulder joint:

Deltoid
Rotator cuff (subscapularis, supraspinatus, infraspinatus and the

teres minor)

Trapezius
Rhomboid
Levator scapulae

Arms

Triceps
Biceps
Forearm muscles

Abdomen:

Rectus abdominis (straight abdominal muscle)
Obliquus externus abdominis (external oblique muscle)
Obliquus internus abdominis (internal oblique muscle)
Transversus abdominis (transverse abdominal muscle, 'corset muscle')

(Lower) back and spine:

Erector spinae
Lumbar multifidus
Quadratus lumborum

Dumbbell shoulder press setup

Sit on a bench with the backrest (almost) fully upright and the dumbbells on your knees.
Raise your knees one at a time and bring the dumbbells to their starting position: The hands are approximately level with the ears. The elbows are beside the torso. The palms are turned forward.
If necessary, press your buttocks back against the backrest. They may tend to slide forward when bringing the dumbbells up. If your waist has shifted too far forward, you are leaning too far back and the chest muscles take over a greater part of the load from the shoulders.

Dumbbell shoulder press technique

The three heads of the deltoid

The deltoid muscle pulls on the upper arms from three directions. During the shoulder press, all three of these "heads" of the shoulder muscle are engaged. However, it is mainly the front head (pars clavicularis) that does most of the work, followed by the lateral head (pars acromiaca). The rear head (pars spinalis) is engaged considerably less.

The shoulder press can be performed in different ways that can shift the load between the heads, but not by much. In most cases, the front of the shoulder produces three times as much effort as the side, which in turn produces an average of three times as much effort as the rear.

Seated or standing

Research has shown that when the shoulder press is performed standing, (all three heads of) the shoulders produce greater effort. The researchers point to the additional need for stabilization when the exercise is performed standing. This would mean that the standing version is 'more effective' at engaging the shoulder muscles.

Another possibility, however, is that people often cheat during the seated version. The standing version forces you to stand upright so that you do not fall backward. This limits the possible contribution of the chest muscles. On a bench with a backrest, you often see the backrest set too far back. The buttocks are then shifted somewhat forward, causing the body to lean even farther back. The shoulders then need to produce less effort because the chest, especially the upper chest, can make a greater contribution.

Dumbbells or barbells?

The same study found that the shoulder press with dumbbells challenged the (three heads of the) shoulders more in all cases than the barbell version. Here too, the greater need for stabilization was mentioned as a possible cause.

In addition to the shoulder muscles having to perform more stabilizing work with dumbbells, the exercise's range of motion is also greater. With dumbbells, the hands can move toward each other at the top of the movement, at the point where the barbell version has reached its endpoint.