What is one action performed by the upper fibers of the trapezius?

The upper fibers of the trapezius are primarily responsible for the elevation of the scapula. When these fibers contract, they facilitate the movement of the shoulder blade upward. This action is crucial for various shoulder movements, as well as for maintaining proper posture. The trapezius also plays a role in stabilizing the shoulder girdle, contributing to the overall functionality of the shoulder complex during activities that require reaching overhead or lifting objects.

Understanding the trapezius muscle's actions is important for recognizing how different muscle groups coordinate to facilitate movements. In contrast, the actions associated with scapula depression, shoulder extension, and scapula retraction are primarily controlled by other muscle groups, demonstrating the specific role of the trapezius in shoulder elevation.