Functional unilateral scapular retraction with weight (Shoulder external rotation with scapular retraction/depression strengthening, with dumbbell, standing)

Stand up straight with your feet shoulder width apart.
Hold a weight in the hand of your affected side and bend down into a squat position.
Reach for your opposite knee with the weight.
Simultaneously stand up straight as you pull your shoulder blade down towards your opposite buttock
Your elbow should remain tucked in to your side and the weight should finish at head height.
Control the movement as you return to the starting position and repeat.