What does the term 'diagonal abduction' describe in arm movements?

Diagonal abduction refers to the movement of the arm away from the midline of the body while simultaneously elevating it. This action typically involves a combination of abduction and upward rotation of the arm, resulting in a diagonal pathway as the arm moves. For example, when reaching up and to the side to perform a gesture or to grab an object located diagonally above head height, the arm moves in a manner that aligns with the definition of diagonal abduction. This motion is common in various activities such as throwing or reaching in sports, where the arm moves through a plane that is not purely anterior-posterior or lateral, thus describing a more complex and dynamic form of movement.