Understanding Anatomy for Shoulder Mobility

Shoulder mobility is an essential skill for all pole dancers. Whether your goal is to achieve high level tricks or to swirl and slink around the pole, your shoulders are going to be asked to really step up their strength and flexibility.

The foundations you set at the beginning of your study will help to determine how your training progresses, and whether your shoulders help you fly or get tight and/or injured.

I’ve put together a series of posts highlighting bits of shoulder knowledge that I think every pole dancer and aerialist (beginner and veteran) should know to inform your training and guide you to success.

In this week’s shoulder tidbits for pole dancers… let’s talk about shoulder anatomy.

Shoulder Anatomy: The 4 Joints of the Shoulder

The shoulder is actually made up of 4 different joints! Let’s learn more about them and how they interact.

Joint #1: The Sternoclavicular Joint

This joint doesn’t get a lot of attention because it has a small range of motion and not a lot of direct muscular attachments. However it is important because this is the only joint that connects the shoulder and arm to the body! All of the other joints are floating around, connected to the body only by muscle.

Injuries to the sternoclavicular joint are usually from falls or other sudden blows that dislocate the clavicle from the sternum, but this joint can also fall into displacement if you overuse your neck muscles to try to stabilize your head and shoulders. If your other shoulder joints are working well then this joint will probably be healthy too.

Joint #2: The Acromioclavicular Joint

The acromioclavicular joint also has very little mobility. The clavicle and the shoulder blade and shoulder socket are held together with very strong, tough ligaments that prevent a lot of movement. However if you happen to fall on your shoulder you can injure the ligaments of the AC joint, causing a “shoulder separation” that can take a while to heal. Keeping the other muscles of the shoulder strong can reduce the risk of an AC joint injury.

Joint #3: The Glenohumeral Joint

The glenohumeral joint is what we usually refer to when we talk about the shoulder joint. It is a ball and socket joint where the knobby head of the upper arm bone (the humerus) meets the shallow socket made by the outer part of the shoulder blade.

The arm bone is attached to the shoulder by some ligaments and a lot of different muscles including the famous rotator cuff muscles that both stabilize and mobilize the shoulder joint.

The glenohumeral joint is very good at rotation and it can move in all directions but it cannot move above 70-90 degrees. That means that if there is no movement of the other joints, the arm would never lift above shoulder height. This is very, very important information!

Joint #4: The Scapulothoracic Joint or Shoulder Blade

The scapulothoracic joint is the unsung hero of shoulder mobility. This is where the scapulae or shoulder blades (same thing) sit against the upper rib cage. It is a gliding joint, so that means that the shoulder blade is just skating around on the surface of the ribs.

The shoulder blade is not attached to the ribs by anything except muscles! No ligaments. No cartilage. Just glorious muscles. This means that the shoulder blades are extremely mobile when they are functioning correctly!

I generally find that the majority of clients who walk through my door with shoulder issues have not paid enough attention to training their shoulder blades. The shoulder blades can and should move up, down, in, out, and be able to rotate up and down with precision, strength, and control.

How the Shoulder Blade and Shoulder Socket Interact

The relationship between the shoulder blade and the shoulder socket is like a pair of tango dancers. Everything that each joint does affects and is affected by the other. They dance together in an intricate choreography that can be powerful and lovely, or they trip over each other’s feet and make a mess!

Remember that the glenohumeral joint only has 70-90 degrees of movement. That means that any movement lifting the arm to be above shoulder height requires that the shoulder blade rotate upwards to get that shoulder socket pointed in the right direction for full use of the shoulder.

Also, almost all of the muscles that control the arm bone, including those famous rotator cuff muscles, attach to the shoulder blade. This means that shoulder blade position affects how those muscles work.

So the moral of the story is… do you know where your shoulder blade is?

This post dives into the rotator cuff muscles and glenohumeral stability. Try not to get too excited!

In the meantime, here is a little shoulder workout that helps to build your strength and flexibility together and teaches your shoulder blades and shoulder socket how to be good dance partners!

Happy Bendings,

Kristina