Eccentric GHjt scaption from 90 degrees with weight (Scapular plane abduction strengthening eccentric, from 90°, with dumbbell, standing)

Stand up straight with your neck long and your shoulder blades gently pulled together.
Hold a weight in the hand of your arm to be exercised and fully bend your elbow.
Using your other arm, lift your exercised arm up to shoulder height.
Ensure your neck remains long.
Straighten your arm to be exercised, and remove the support of your lifting arm.
With your thumb pointing up, slowly lower your arm diagonally back down to your side.
Repeat this movement.