The standing scapular retraction or scap squeeze is designed to strengthen the muscles between your shoulder blades, leading to improved posture and decreasing the stress on your neck, shoulders and thoracic spine.
Get into a comfortable standing position with your feet hip width apart. You should be standing in good alignment with your shoulders stacked on top of your hips. Imagine that a string is pulling you upward, lengthening your spine.
Squeeze your shoulder blades together. Hold this position for 5 seconds. You can pretend that you are trying to squeeze a pencil between your shoulder blades.