biacromial

Biacromial is a anatomical term used to describe structures or measurements related to both acromion processes of the scapulae. The acromion is the lateral bony projection at the top of the shoulder blade that forms part of the shoulder joint. The prefix bi- means two, so biacromial refers to the relationship between the left and right acromial prominences.

In anthropometry, the biacromial diameter, also called biacromial breadth, is the distance between the most lateral points of the left and right acromion processes. This measurement is a key index of shoulder width and is typically obtained with a tape measure or calipers, with the subject standing upright and the arms at the sides. Biacromial breadth varies with sex, age, ethnicity, and body size; generally it is larger in males than in females and increases with overall body size.

Clinically and practically, biacromial breadth informs clothing and PPE sizing, ergonomic design, and seating or equipment layouts that require accommodation of shoulder width. In radiology or clinical assessment, biacromial dimensions may be considered when evaluating thoracic width or planning procedures where shoulder anatomy influences technique or access. The term can also appear in descriptions of bilateral shoulder girdle anatomy, referring to structures or measurements involving both acromial regions rather than a single side.