The hominin fossil record is consistent with the evolution of the more laterally oriented joint of the modern human shoulder from that of a cranially positioned suspensory ancestor. Across humans, scapular shape does vary with cranial-lateral orientation correlated with changes in rotator cuff mechanical advantage. This study examined how cranial-lateral shape changes in the human scapula alters glenohumeral ligament function. This is important because the highly mobile shoulder is constrained partly by ligaments, thus changes in scapular morphology may lead to changes in ligament function. We created a novel approach by using PCA to generate shape models from n = 51 scapulae to capture the range of lateral and cranial orientation across humans and applied glenohumeral abduction kinematics to each shape model while optimizing for congruence. Ligaments were then modeled as fiber-reinforced finite element shells in Artisynth and ligament length was compared across shapes for inferior and superior ligaments at their extreme ranges of elongation. Compared to a laterally oriented glenoid, a cranially oriented glenoid had a 12.7% longer superior glenohumeral ligament at low abduction and an 8.3% shorter inferior axillary ligament at high abduction. However, the coracohumeral ligament displayed minimal variations across scapulae (2.5%) at low abduction. These results suggest that a cranially oriented scapula enables higher levels of abduction, which is consistent with arboreal primates possessing cranial scapulae that function at high ranges of abduction. However, changes in ligament length may occur with a cost to stability.