The action at the shoulder joint (humerus in socket) during the lowering phase of a lateral raise:

During the lowering phase of a lateral raise, the humerus moves back towards the midline of the body after it has been raised out to the side. This movement can be categorized as adduction, which signifies the action of bringing a limb closer to the body's center.

In this particular context, when you lower your arms from an elevated lateral position, the humerus travels through the shoulder joint back towards the side of the body, facilitating adduction. This is a fundamental movement in the shoulder joint that occurs as part of the natural biomechanics during the lowering of the arms from the fully raised position.

Understanding this movement is crucial for assessing shoulder joint mechanics and ensuring proper form during exercises, which can help prevent injury and enhance performance. Adduction is often characterized by the action of muscles such as the latissimus dorsi and teres major, which help to draw the upper arm down towards the body.

The other options pertain to different movements that do not accurately describe the action occurring in the shoulder joint during this specific phase of the lateral raise.