What is the primary function of the acromioclavicular joint?

The primary function of the acromioclavicular joint is to stabilize the relationship between the clavicle and scapula during glenohumeral (GH) range of motion. This joint plays a crucial role in maintaining proper alignment and function of the shoulder girdle, which is essential for effective upper extremity movement.

By stabilizing the clavicle and scapula, the acromioclavicular joint allows for coordinated movements of the shoulder, particularly during activities that involve overhead motions or lifting. This stabilization helps prevent injuries and ensures that the forces acting on the shoulder are appropriately distributed, promoting overall shoulder function and mobility.

In contrast, the other options do not describe the primary role of the acromioclavicular joint. The elbow joint is not influenced directly by the acromioclavicular joint, and spinal rotation does not involve this junction. Additionally, while shoulder flexion is an important movement, it is not the primary function of the acromioclavicular joint; rather, it supports stability during such movements.