What is shoulder blade retraction with resistance?

Scapular exercise: Retraction

1. Put the band around a solid object at about waist level. (A bedpost will work well.) Each hand should hold an end of the band.
2. With your elbows at your sides and bent to 90 degrees, pull the band back. Your shoulder blades should move toward each other. Then move your arms back where you started.
3. Repeat 8 to 12 times.
4. If you have good range of motion in your shoulders, try this exercise with your arms lifted out to the sides. Keep your elbows at a 90-degree angle. Raise the elastic band up to about shoulder level. Pull the band back to move your shoulder blades toward each other. Then move your arms back where you started.