Which structures make up the acromioclavicular joint?

The acromioclavicular joint is formed by the acromion process of the scapula and the lateral end of the clavicle. This joint plays a crucial role in shoulder mechanics, as it allows for the connection between the shoulder girdle (composed of the clavicle and scapula) and the trunk.

The acromion process acts as a bony prominence at the top of the scapula, while the lateral end of the clavicle serves as the collarbone's terminal part, providing stability and a point for muscle attachment. The articulation between these two structures allows for a range of motion at the shoulder, including movement during arm elevation and rotation, which is essential in many functional activities.

Understanding the structure of the acromioclavicular joint is vital for recognizing how injuries or conditions affecting it, such as shoulder separations or arthritis, can impact overall shoulder function and mobility.