These side-lying exercises focus on the back of the shoulder – namely the posterior delt and rotator cuff muscles. By doing them as a tri-set, we create a potent stimulus to promote growth and resilience.
Grab a light dumbbell. Strong lifters will typically use 5-10 pounds. Do 10 reps of each with no rest between exercises.
Benefits include increased load in the stretched position and the elimination of body English, which is what plagues standing variations. It also hits the rotator cuff muscles, teres minor, and infraspinatus.
"Scaption" sounds like a weird word, but it's actually a natural movement for the shoulder that occurs between the sagittal plane (plane of flexion/extension) and frontal plane (plane of abduction/adduction).
This exercise requires the posterior delt, teres minor, and infraspinatus to maintain the arm above the level of your torso as the supraspinatus, middle deltoid, and upward rotators of the scapula produce the movement.
This rehab mainstay has a place in every healthy lifter's program. Think about spinning along the long axis of the upper arm. If you've never done this exercise before, place a folded towel on the ribcage and rotate the upper arm on it.
Don't stop at just one round, though. After you've completed a tri-set for each arm, immediately begin a second or third.