Lie on your side on a flat bench. Begin with a very
light dumbell in hand and your arm down across your
chest. If you are rehabbing an injury, use 1 to 5
lbs. at most, if conditioning to prevent injury, 1 to
12 lbs. is recommended. It is recommended that you
not use heavier weights for this exercise as the rear
delt has extremely poor leverage in this position and
a small increase in weight represents a big increase
in stress.
Keeping a slight but constant bend in the
elbow, slowly lift the weight until your arm is almost
pointing straight up. Do not roll back as you do the
exercise, keep your upper body in the same plane
throughout the movement.