The superficial or investing layer (green line) is superiorly attached to the superior nuchal line of the occipital, the mastoid process of the temporal bone and the inferior border of the mandible, and inferiorly to the manubrium, clavicles and scapula; laterally it merges with subcutaneous tissues of the neck.
Broad entheses would result in less stress concentration than focussed entheses such as the triceps insertion on the olecranon, so positive allometry may not be as necessary in the scapula as it is in the epiphyses of long bones.
Instead it is projected mesially as far as the subcoracoid region and then reflected onto the anterior surface of the neck of the scapula until it reaches the periphery of the labrum.
In mammals that use the forelimb for support in standing, the vertebral margin is the shortest, and the long axis of the scapula runs from it to the glenoid cavity; but in those whose forelimb is used for prehension, or grasping, such as in the primates, or for flight, such as in the bats, the vertebral margin is elongated, and the distance from it to the glenoid cavity is decreased.
Congenital elevation of the scapula is rare, but it is the commonest deformity of the upper extremity and the shoulder girdle [13].
If we remember the possibility of fracture or pseudo-arthrosis of the spine of the scapula and look for it on the roentgenograms, we do not miss the diagnosis.
The human pectoralis minor muscle has forsaken its attachment to the humerus, the long bone of the upper arm, and presumably derives some stability from attaching to the coracoid process, a projection from the scapula, instead of gliding over it.
This concept does not directly address the pathomechanics of an ACJ injury in which, rather than a superior displacement of the clavicle, it is the scapula that descends [1].
Toward the end of September, I knew that whatever thing was happening to me was most certainly beyond the realm of any rotator cuff injury, because my scapula started to feel like it was protruding from the muscles in my back.
The ventral end of the scapula is not complete, although it can be determined that the acromial process formed an angle of approximately 45 degrees with the dorsoventral axis of the scapula, as in non-eusauropod sauropodomorphs (with the exception of Saturnalia tupiniquim, Coloradisaurus brevis, Lufengosaurus huenei, Massospondylus carinatus).
