3-D Shoulder: Subtle Shoulder Instability Probable Suspects

Another round of THANKS to Dr. David Tiberio for his guidance on shoulder instability using Applied Functional Science!!!


As I continue this exploration of the shoulder, I am starting to really get into the complexity of the human body. Looking through the Applied Functional Science glasses, I really am able to see the antaomy and function of the shoulder in a different light from what I was originally taught and its amazing. As we progress on our respective paths, I am encountering more and more people who either have acute or chronic shoulder issues, but what I'm also finding is that many people have "dysfunctional" shoulder complexes and don't even know it. Who would have thought a gunked up scapula or glenohumeral joint instability can cause a global shift of function in the body?

In this post, I will focus more on the 3-D Shoulder with an overview of subtle shoulder instability as well as some PROBABLE SUSPECTS that we can go to.  If you are just linking in to this blog, please see my other two blog posts: Introduction to the 3-D Shoulder and 3-D Shoulder: Rotator Cuff Impingements and Probable Suspects for more on the 3-D shoulder.

In the research article published in the American Journal of Sports Medicine "The Pathophysiology of Shoulder Instability" by Dr. William Levine and Dr. Evean Flatow, they stated that "an intricate balancce between the static and dynamic stabilizers confers the stability of the shoulder joint. Static stabilizers include the glenoid labrum, glenohumeral ligaments and capsule and rotator interval. The dynamic contstraints include the rotator cuff musculature and the scapular rotator muscles. Any imbalance in this relationship can lead to shoulder instability."

There is so much wisdom in this statement and I suggest if you want to read more in-depth, please refer to this article.

This post will really take into consideration that there is no history of subluxation or dislocation of the shoulder. If we are looking where the instability in this case, we really do not have to look much further. This is more for the athletes who may experience pain and feel that the shoulder is unstable during activities.

TOO MUCH OF A GOOD THING???

As I observe my athletes practice their sports on a daily basis, it's refreshing to see that they are very dedicated to improving themselves through diligence and tenacity. Their goals of optimal peformance are commendable and I encourage it. On the other hand, I have to look at them and say "Where are we falling on the GOLDILOCKS scale"?

We all remember the story of the "Goldilocks and the 3 Bears" right? Goldilocks went through the 3 Bears chairs, food and finally beds giving each one a "Too much" "Too little" or "Just right". I love this analogy because as I see many of my athletes, they are all over the scale. Too little and  Just right are fine places to be regarding injury prevention. It's when we get to "TOO MUCH" where we start to have repetitive strain injuries.

When we talk about repetitive strain injuries, we are talking about the soft tissues of the body. During these activities, like throwing a baseball, the tissues are under a good deal of stress from the movement, but usually it's not enough stress to cause an acute traumatic injury. HOWEVER, we see that this stress over time catches up to us. Overtime, like in baseball, these static and dynamic stabilizers are being stretched and thats where we come to have this "Subtle Shoulder Instability".

PROBABLE SUSPECTS WITH SUBTLE SHOULDER INSTABILITY

Working with injuries, our first inclination is to go that area of insult and say "Oh shoulder! You're inflammed, swollen and painful. You are being a bad shoulder so we are going to ice, stim and give you anti-inflammatories to calm you down!!!" Well, speaking from experience, when I hurt my shoulder, all I wanted was for the pain to go away. I had been doing a lot of conditioning of my athletes and working with either tennis balls, lacrosse balls or medicine balls. Well, this lead to some pain and instability in my shoulder over the course of time. I heated, used electric stim, iced and took NSAIDS to manage my symptoms but that was not enough. I knew there had to be something else that caused the soft tissue of the shoulder complex to become dysfunctional. Here are two PROBABLE SUSPECTS that I went to.

1) LACK OF MOTION SOMEWHERE OTHER THAN THE GLENOHUMERAL JOINT.

• Understanding that Function is DRIVEN is something that we anchor to. In the case of the shoulder, it can be driven by many things. Gravity, momentum, as well as other body parts like the hand, hips even feet. If we look up the kinetic chain and see that there is limited motion at a joint like the hip or scapulothoracic joint, the glenohumeral joint, to complete the task at hand, will allow for more motion. More motion means more stress on the soft tissue which overtime can lead to the SUBTLE SHOULDER INSTABILITY.

2) A DYSYNCHRONY IN THE KINETIC CHAIN SEQUENCING.

• If all of the necessary movment is there in certain joints, we then need the body to sequence in a way that efficiently completes the task. For instance, in Applied Functional Science, we refer to something that is called the TRANSFORMATIONAL ZONE (TZ). This is when we move changing from a "load" to an "explode" in the movments or vice versa. For instance, a TZ is going from bending over to pick up a piece of trash to coming up to standing. When we are going down toward the ground, joints and muscles are eccentrically loading so when we get the trash in our hand, we can "explode" or concentrically contract the muscles so that we can come to standing. The TZ is the moment of movement reversal.
• With the sequencing in a baseball pitch, the TZ of loading up the musculature and exploding to throw the ball is a place where some pitchers start to have an issue. In the late cocking phase, we see the hand being loaded backward. This movement backwards of the hand is still loading where we see a distal segment deceleration, HOWEVER, we also see the proximal segement or the trunk going in the opposite direction with a proximal segment accceleration. If the the sequencing is off, and we see the proximal segment accelerating as the distal segment is still decelerating, we will again, see the soft tissue stressed and over time, we may see that same repettitive strain injury causing shoulder instability.

BIG "ROCKS" TO LOOK AT

• Thoracic Spine
• Hips
• Foot/Ankle
• Lack of motion in the Cervical spine. This is important in sports like baseball where the pitchers eyes have to stay on the target as the rest of the spine has to go into a rotation.

If one of the links of the chain is unstable, the proprioceptors of the body will sense this and deal with the lack of stability before the mobility/load/explode, like in the foot. For instance, if we are dealing with a Chronic Ankle Instability, the body, instead of allowing the pitcher to fall backwards too much because of the lack of stability, will have the person go into the explode a little earlier. The mind has told the body what it wants to do. "GO FORWARD" The body will go towards the target and explode and not the load. This sequencing error along with the instability puts the tissues at the glenohumeral joint under more stress than it may need to have.

Again, there are many articles written about shoulder instability but I wanted to share the experience through Applied Functional Science.

If you have any feedback or comments, please leave them in the COMMENTS section or email me at yoga-pilates_will@hotmail.com.

Happy Monday!!!!

Will