We know that a greater contribution of the supraspinatus is required
during the first 15-30 degrees of a lateral raise and medial deltoid
activity peaks at 90-120 degrees. So how do we use this information to
Well, if you want to stress the supraspinatus fibers more, like 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.
If your goal is to build barn-door wide shoulders, then go with lean-away dumbbell laterals or tube laterals where you overload the top range.
For fun, combine a tube with dumbbells and use a jettison technique where you release the tube once you reach failure and continue with just the dumbbells until there’s nothing left.