Strategic Shift Under the Shoulder Blades
Firstly, loosen up
1 Loosen pectoral minor muscle,The origin of the pectoral minor muscle is on ribs 3 and 4, and its insertion point is at the acromion process of the scapula. The pectoral minor muscle is easily fatigued and contracted due to movements such as dumbbell presses and overhead presses, causing it to pull the scapula forward.

2 Loosen trapezoid muscle,The insertion point of the trapezoid muscle is also on the scapula. Tension in the upper portion of the trapezoid muscle can cause scapular elevation.

3 Loosen rhomboid muscle,The insertion point of the rhomboid muscle is on the first rib. Tension in the rhomboid muscle pulls on the cervical vertebrae forward, causing postural kyphosis and indirectly causing scapular elevation.

4 Loosen trapezius muscle,The trapezius muscle, which elevates the scapula near the spine, easily causes scapular elevation.
5 Loose the shoulder sleeve muscles,Tension in the shoulder sleeve muscles can cause the scapula to move outward and upward, closer to the shoulder joint and humerus. While increasing the stability of the shoulder joint, it reduces the range of motion of the scapula.

Loosening methods include stretching and massage
After loosening, activate muscles that cause the scapula to descend.
1 Activate the lower portion of the trapezoid muscle, you can take the action of extending your arms vertically upwards and then moving your scapula up and down to activate it.


Image from Super Oxygen Training Class, more detailed answers please consult the background
2 Activate the anterior deltoid, you can take the action of scapula resistance band antiform to activate it.

Image from Super Oxygen Training Class, more detailed answers please consult the background
3 Activate the latissimus dorsi, the latissimus dorsi stabilizes the scapula during pulling down or pull-ups. Pay attention to tightening the scapula when doing pulling down or pull-ups, don't let it move upwards as a compensation.

4 Activate the shoulder sleeve muscles, stable shoulder sleeve muscles can reduce scapular compensation and prevent scapular elevation.
After doing all this, you will find that the scapula descends and the person becomes more upright, improving kyphosis, and even a slender neck and clavicle appear. At this time, you can practice standard movements such as dumbbell presses.
Remember this feeling, most of humanity's aesthetic viewpoints start from healthy and strong. So if a person's posture is wrong, his muscle activation may not be good. The same principle applies, if a person has a straight and elegant posture, it indicates that his body structure is more in line with the biomechanics of the human body, and it is easier to develop a high level of training.