Written By: Kevin Cann
Our shoulder joint is the most mobile joint within the human body. The head of the humerus sits on the scapula like a golf ball on a tee. Due to the joint’s structure and nearly 360 degrees of motion, our passive and active tissues must do a lot to keep the joint stable.
First, we have our labrum which gives the joint a deeper socket in which to move, providing some of the stability. We also have passive tissues such as ligaments that help control the position of the joint and disallow it from getting into positions where we might get injured.
Even with the labrum and the passive tissues, the shoulder joint is still quite loose in various positions. This means that our muscles must do the majority of stabilization in the joint during activities of life and sport. Our rotator cuff must work together to help keep the head of the humerus centered in the glenoid (this is the bony structure of the scapula that acts as the tee in the joint.).
When muscles on opposite sides of a joint work together to generate the same action it is known as a force coupling. This is the primary job of the rotator cuff, to provide stability in the joint. Often times we go into the gym and we see people performing specific shoulder external and internal rotational exercises to strengthen their shoulder or warmup their joint.
Why would we want to mobilize a joint or muscle group when their primary function is to stabilize the shoulder? If we are missing shoulder joint range of motion, you need to look at the cervical and thoracic spine first. In my over ten years of experience in this field I have never come across a client that needed to mobilize their rotator cuff.
Strengthening the individual cuff muscles may be important after direct trauma, such as surgery. However, in the majority of people in the gym the rotator cuff is not weak. The muscles are in essence, too small to become weak. Instead they don’t do their job well because of the timing of muscle firing.
We need the smaller intrinsic muscles, like the rotator cuff, to fire first and get that head of the humerus centered in the joint. From there our larger muscles provide us directional movement. However, we tend to sit in some really shitty positions all day long.
Our spinal mechanics are going to drive shoulder mechanics. If we sit hunched at a desk all day long our head gets pushed forward, spine rounds, and scapulas protract. All of these actions change where the humerus sits in the joint. This leaves us with less than optimal joint centration.
When we have less than optimal joint centration, the mechanics of the joint change. Our central nervous system will always choose the path of least resistance to drive movement. Changing the position of the humerus changes leverages of the muscles around the joint. This leads to larger muscles providing stability of the joint. The problem with the larger muscles doing the primary stabilization of the joint is they are not as good at it as the rotator cuff.
The rotator cuff goes from the scapula to the top of the humerus. Basically, it covers the joint like a blanket. Leverages could not be better to provide joint stability. If we call on secondary stabilizers such as the delts to stabilize the shoulder, we lose this advantage. From the poor postures we are in all day long we tend to have muscle imbalances within these secondary stabilizers as well. This further drives the humerus out of position and further drives poor mechanics. This is where we usually feel some type of impingement or pain. Over time this will lead to injury. Perhaps, this is why the majority of people over 40 years of age have some wear and tear to their labrum.
So how do we retrain our body to get into good positions and stabilize the shoulder properly? It starts with exercises like deadlifts and Farmer’s Walks. Every client that comes to me with shoulder pain performs both of those exercises in the first phase of their training (barring they are cleared to with the assessment).
I have stated many times in past articles that getting stronger is corrective exercise. When we grab onto heavy weight we squeeze the bar as hard as we can and it improves grip strength. When we grip something hard we send a message to our body telling it to get ready to lift up something heavy. One of the things that happens to get ready to lift something heavy is our rotator cuff turns on. Studies have shown a positive correlation between griping activities and rotator cuff activity.
Not only does gripping turn on the rotator cuff, but it shuts off the deltoids. This allows our shoulder to get into the right position. Our shoulder is also most stable when our hands are down by our sides. It becomes increasingly less stable as we move our arm towards an overhead position. This is why exercises like overhead pressing may be a bad idea for people with past shoulder pathologies. In the deadlift our arms are at our sides so we are in a stable position and we have just made it more stable by gripping the bar hard.
As the bar goes to break the floor, the weight of it pulls on our arms. This distraction force creates even more of a neurological response. This increases the tension of the cuff to stabilize the joint and to work properly with the global muscles to direct movement.
The deadlift also helps us retrain proper timing of muscle firing. When we squeeze the bar hard to setup, we are getting the rotator cuff to fire first and center the humerus before we move. The deadlift also teaches us how to properly organize and stabilize our spine when it is done correctly. This helps offset the poor postures of our daily tasks. The Farmer’s Walks work the same way as the deadlift.
If you suffer from shoulder pain, remove any overhead work from your program immediately and add in some deadlifts and Farmer’s Walks. Once the shoulder starts feeling better add in some exercises that increase the shoulder stability requirements such as crawls. When the crawls feel good, add in pushups and rows. From here I like to progress to overhead carries like waiter’s walks and begin using the kettlebell for overhead work. The way that the weight pulls on the joint with the kettlebell makes the rotator cuff fire. This is why people with shoulder pain overhead can often use kettlebells pain free. Once we demonstrate good ability with the kettlebell overhead we will move on to dumbbell and barbell overhead work.