Scapular retraction refers to moving the shoulder blades (scapula) towards the spine. The opposite is protraction – moving the shoulder blades away from the spine. If you give yourself a big bear hug your shoulder blades will protract. If you try to pinch your shoulder blades all the way together they will retract. If you fully protract, fully retract, and then find the spot in the middle you will have found neutral.
Scapular depression refers to moving the shoulder blades down away from your ears. The opposite is elevation – bringing the shoulder blades closer to the ears. Shrugging is elevation, the opposite movement is depression. As with retraction, neutral is the spot in the middle of elevation and depression.
Many lifts require you to be aware of the position your shoulder blades have taken. Deadlifts and Squats require strong retraction and depression. Back exercises such as rows, pull downs, or chin-ups require controlled movement through all positions, depending on the exercise. (*Protraction and elevation may or may not apply depending on the individual). Even chest and shoulder exercises are influenced by the positioning and movement of the scapula.
Most people are very unaware of these movements and their scapula may even be stuck in one position. This can lead to shoulder, back, neck, and other chronic pains. If you observe you will find that many people walk around in an elevated and protracted position (shoulders rounded forward and shrugging). Over time this leads to the hunch backed position we often observe in aging population.