The Shoulder Girdle, Part 2: Movements and Muscles

In Part 1 of my shoulder series, which you can find HERE, I talked about the bones and joints of the shoulder girdle. Today I’ll be going over the movements and the muscles of the shoulder girdle. So, let’s get to it!

When identifying movements of the shoulder girdle, it helps to focus on a bony landmark of the scapula. The inferior angle of the scapula, the glenoid fossa, or the acromion process are all acceptable options. Movements of the shoulder girdle are pretty much movements of the scapula, with the sternoclavicular (SC) joint serving as a pivot point. As the scapula moves, watch where your bony landmark moves, and that will help you determine what shoulder girdle movement is being performed.

Primary Movements of the Shoulder Girdle

Abduction (Protraction) – Lateral movement of the scapula away from the spinal column. Protraction occurs at the top part of a pushup, in scapular pushups, and in forearm wall slides when moving your forearms to the wall.

Adduction (Retraction) – Medial movement of the scapula toward the spinal column. Whenever you pinch your shoulder blades together, you are adducting, or retracting, your scapulae. This also occurs in the forearm wall slide.

Elevation – Superior movement of the scapula. When you shrug your shoulders, you are elevating your scapulae.

Depression – Inferior movement of the scapula. Depression of the scapulae is optimal in many strength exercises and mobility exercises in the gym. In deadlifting and in the no money drill, the scapulae stay depressed at all times.

Upward Rotation – Turning the glenoid fossa upward coupled with superior and lateral movement of the inferior angle of the scapula away from the spinal column. This happens when simply raising your arm out to the side, as well as in scapular wall slides.

Downward Rotation – Returning the glenoid fossa to its normal position accompanied by medial and inferior movement of the inferior angle of the scapula toward the spinal column. Bringing your arm down to your side and scapular wall slides both involve downward rotation.

As the above title suggested, these are the primary movements of the shoulder girdle. There are other movements where the scapula must rotate or tilt on its axis, but for now, we’ll keep things simple and leave those on the backburner for another time.

Muscles of the Shoulder Girdle

There are 5 muscles primarily involved in movements of the shoulder girdle. All of these muscles originate on the axial skeleton (the skull, spinal vertebrae, or ribs to be exact) and insert on the scapula and/or the clavicle. These muscles play a very important role in dynamic stabilization of the scapula as well as in posture. For the sake of brevity, I’ll give a brief description of where the muscle is located and the movements that it causes.

Trapezius

The trapezius is located posteriorly in relation to the trunk. This muscle is divided into 3 parts: the upper fibers, middle fibers, and lower fibers. The upper fibers are involved in elevation, upward rotation, and extension and rotation of the head. The middle fibers retract and upwardly rotate the scapula. The lower fibers perform retraction, upward rotation, and depression.

Levator Scapulae

The levator scapulae is also located posteriorly to the trunk. It elevates and downwardly rotates the scapula and can also extend the neck and laterally flex and rotate the head to the same side.

Rhomboids

The rhomboids (referred to as rhomboideus in the picture above) are located posteriorly to the trunk as well. There are 2 rhomboid muscles: rhomboid major and rhomboid minor. Rhomboid minor is superior to rhomboid major and smaller, but both are located deep (below) to the trapezius. Both rhomboid muscles perform the same functions, which are retraction, elevation, and downward rotation.

Serratus Anterior

The serratus anterior is located posteriorly and laterally to the trunk. This muscle protracts and upwardly rotates the scapula.

Pectoralis Minor

The pectoralis minor is located anteriorly to the trunk. It is deep to the pectoralis major and it protracts, depresses, and downwardly rotates the scapula. It is important to note that the pectoralis minor is the only muscle that can both depress and downwardly rotate the scapula.

I know this was a long post, so take a deep breath because you made it all the way through! Thank you for reading and hopefully you’ve increased your knowledge of the shoulder girdle!

About these ads

4 thoughts on “The Shoulder Girdle, Part 2: Movements and Muscles

  1. NIce breakdown. Clarified much of the confusion I had about the different types of movements one makes with the shoulder… seeing cutaway pictures of the muscles that trigger those motions was a bonus.

    Maybe a future post could examine the hip joint (particularly relating to kicking in swimming) or elbow joint? There’s a lot of talk about how shoulder impingments result from excessive shoulder internal rotation, but I Coach G. John Mullen’s post on swimmingworldmagazine today talked about pronating the forearm. I’m wondering if one can train the ability to rotate the forearm while keeping the shoulder neutral/externall rotated.

    Thanks for the info!

  2. Pingback: Recommended Reading:Power, Shoulder Muscles, Breathing, Hip Flexors, Vagen Videos | Sayco Performance Athletics

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s