In human anatomy, the acromion is a bony process on the scapula. Together with the coracoid process, it extends laterally over the shoulder joint. The acromion is a continuation of the scapular spine, and hooks over anteriorly. It articulates with the clavicle to form the acromioclavicular joint.

The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up of three distinct sets of muscle fibers, namely theanterior or clavicular part posterior or scapular part intermediate or acromial part