Posterior Tilt

Scapular posterior tilt is a three-dimensional rotational movement of the scapula around an approximately medial-to-lateral axis. During posterior tilt, the superior portion of the scapula moves posteriorly while the inferior angle moves anteriorly toward the thorax. It is the opposite of scapular anterior tilt .¹

Posterior tilt is a normal component of arm elevation. As the arm is raised overhead, the scapula generally moves into increasing upward rotation and posterior tilt, while external rotation also often occurs. These rotations occur together rather than as isolated movements and continually adjust the scapula's orientation relative to the humerus and thorax .^1,2

The serratus anterior is an important muscular contributor to posterior tilt. Its action can contribute to posterior tilt along with upward rotation and external rotation of the scapula. The trapezius works with the serratus anterior as part of the coordinated muscular control of scapular movement during arm elevation .³

Posterior tilt should not be confused with scapular upward rotation. Posterior tilt describes rotation in which the inferior angle moves anteriorly, whereas upward rotation moves the inferior angle laterally and turns the glenoid more superiorly. Both generally increase during arm elevation, but they represent different rotational components of scapular motion. Considerable normal variation exists between individuals, so a single amount of posterior tilt should not automatically be interpreted as normal or abnormal .^1,2