Using a computational force-vector model and two separate cadaveric experiments, Labriola et al. ask how individual shoulder muscle forces shift the resultant joint vector relative to the balance stability angle — and whether dysfunctional muscle activity alone can replicate clinical glenohumeral dislocation and capsulolabral injury.
When counseling a patient on anterior instability rehabilitation, this study gives you the biomechanical rationale: prioritize infraspinatus/supraspinatus/teres minor strengthening (they redirect the resultant force back inside the balance stability angle), and be cautious with heavy pectoralis major loading in abduction-external rotation — it can paradoxically increase anterior translation rather than stabilize the joint.
Using a computational force-vector model and two separate cadaveric experiments, Labriola et al. ask how individual shoulder muscle forces shift the resultant joint vector relative to the balance stability angle — and whether dysfunctional muscle activity alone can replicate clinical glenohumeral dislocation and capsulolabral injury.
When counseling a patient on anterior instability rehabilitation, this study gives you the biomechanical rationale: prioritize infraspinatus/supraspinatus/teres minor strengthening (they redirect the resultant force back inside the balance stability angle), and be cautious with heavy pectoralis major loading in abduction-external rotation — it can paradoxically increase anterior translation rather than stabilize the joint.