We know that a greater contribution of the supraspinatus is required during the first 15-30 degrees of humeral abduction (which is a technical way of saying “a lateral raise”), and medial deltoid activity peaks at 90-120 degrees. So how do we use this information to our advantage? Well, if you want to stress the supraspinatus fibers more (e.g., during rehab from a rotator cuff repair), then overload the bottom range of the movement. This can be accomplished with side-lying dumbbell laterals done against a Swiss ball, an incline bench, or simply lying on the floor.