Figure 1. Schematic representation of the stabilizing function of the rotator cuff, keeping the humeral head against the glenoid cavity. The transverse torque is exerted by the tendons of the subscapularis and the infraspinatus. The coronal torque is exerted by the deltoid muscle (generating a force vector upwards and outwards) and the rotator cuff (generating a force vector downwards and inwards). Their coordination keeps the humeral head centered against the glenoid cavity. D: deltoid; I: infraspinatus; RC: rotator cuff; O: center of rotation; S: subscapularis. Original drawings.