01/01/2026
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The scapula has two main factors that determine its range of available movement. Firstly, regardless of the type of movement, the acromion must remain close to the clavicle because the AC joint tightly connects them. This also means that, in many cases, the AC joint serves as a center for scapular rotational movements. Secondly, the flat inner surface of the scapula must slide along the rib cage, which means it cannot move into it or too far away from it.
These constraints allow for three primary movements and two supplementary ones. The primary movements are elevation and depression, meaning the scapula moves up and down; protraction and retraction, meaning the scapula moves away from the spine and back toward it; and upward and downward rotation, meaning the scapula rotates at the AC joint while sliding along the rib cage.
The supplementary movements are related to different types of tilting, which will be discussed in upcoming videos.