Thoracic Spine Mobility:
As we discuss on a regular basis at MTS, everything is connected. So, to cut to the chase, is goes like this…
The humerus sits in the glenoid and is stabilized in the glenohumeral joint by the rotator cuff. The rotator cuff originates on the scapula. The scapula sits in close proximity to the ribcage. The ripcage attaches to the Thoracic Spine. Thus, they are all connected. If that simple explanation makes sense, move on to another page, but if you need a more thorough explanation, read on…
The scapula is the foundation for the shoulder. This is hard to ignore. The rotator cuff holds the head of the humerus tight in the joint and allows it to work and glide normally and pain free. The origin of the 4 rotator cuff muscles is the scapula. Thus, if the scapula does not work well, the rotator cuff will have to try to make up for the poor function. Over time, the rotator cuff will become overworked. This is when pain and instability sets in. Thus, without a stable foundation, the shoulder will crumble.
Not So Simple…
What defines a scapula’s function?
The scapula is intended to be a very stable bone (just as the foundation in your house). We do need the scapula to move to allow for a full range of motion for the shoulder. But, the movement should be limited and only at the end ranges of motion.
The problem with many painful or unstable shoulders is that their scapula moves too much. This is usually related to the muscles that stabilize the shoulder, such as the rhomboids and the mid and lower trap.
They are responsible for keeping the scapula in a relatively fixed position and tight to the ribcage. If they are weak and/or not functioning well, the scapula will be unstable and it will likely move too much.
This movement may be medial or lateral, or many times the scapula will “wing” and pull away from the ribcage. Once the scapular stability is lost, so is the stability of the shoulder. This is why upper back strengthening such as rows and retractions are so important for treating and/or preventing shoulder pain.
The T-Spine Connection
So, how does the Thoracic Spine tie into all of this? The T-Spine is intended to rotate, flex and extend. Most athletes do a decent job of flexing their Thoracic Spine, but they struggle with rotate and extension. If an athlete does not have the ability to rotate at their spine, the mobility will have to come from somewhere (the scapula).
As an athlete reaches accross their chest for something, they will need some rotation from their T-Spine. Once they hit their restriction they will have to get the extra motion needed by pulling their scapula away from their rib cage. At that point, the shoulder stability is lost. That’s when the pain sets in.
Essentially, the Thoracic Spine is the foundation for the foundation for the shoulder. If it is tight (and most are), then the foundation for the shoulder has to move and is no longer stabile, and the problem continues up the kinetic chain.
Learn more about how the Thoracic Spine affects other movements:
Learn about mobility of the T-Spine: