It's a common sentiment in baseball that shoulder injuries are to be avoided at all costs. Even the strongest, most durable, and best movers can still hurt their shoulders. The shoulder is one of the least stable joints in the body and there are many variables that can impact the function and health of the shoulder. It's still considered a much bigger question mark on if a thrower can return to pre-injury form following shoulder surgery than if it's an elbow being repaired. We've still got a long way to go to perfect the process with elbow surgery from the initial injury to the return to game action, but it's a much safer bet than shoulder surgery.
There are many different conditions that may occur in the shoulder. The most common are typically surrounding the capsule, the labrum, and the rotator cuff. The surgery options for these injuries are innovative and improving, and the post-op therapy is very good, but where is the disconnect that's causing such a low quality of return?
I commonly see patients that are 8-10 months post-surgery that have graduated through physical therapy, cleared by their surgeon, and have been told they are ready for a return to play. The only problem is that they have limited (comfortable) layback, they may have a slight pinch, and they just don't feel comfortable throwing. They pass all of their therapy and strength tests, the surgeon says that integrity looks and feels great, so what the heck is going on? It's not necessarily a problem with the system, but more about a missing piece within the system. The key missing piece is closed-chain stability.
Why I believe that this is such a pivotal aspect to shoulder rehab goes back to what was mentioned earlier about the shoulder being one of the least stable joints in the body. The brain will look for solutions to try to stabilize that shoulder. When the shoulder gets de-conditioned in the time from injury to the start of rehab its predisposition to return to bigger, multi-joint compensatory muscles increases. It may not have great control and activation of the periscapular muscles that help stabilize and guide the bigger compensatory muscles.
So how do we fix this? Well, let's look at the anatomy first.
The glenohumeral joint (shoulder) consists of 4 rotator cuff muscles which are the Subscapularis, which it's main movement is internal rotation. Infraspinatus, which it's main movement is external rotation. Teres Minor, which it's main movement is also external rotation. Lastly, Supraspinatus, which it's main movement is abduction. The reason I say main movement is because they also work to stabilize the joint by keeping the ball of the humerus centered in the glenoid (golf ball on tee analogy) which is called joint centration. When the muscles are balanced and working together to keep the force vector centered in the joint then the joint undergoes the least amount of stress to one side of the joint over the others while also exhibiting optimum force transfer to the next joint segment in whatever movement chain that is being used. THIS CONCEPT IS IMPORTANT!
There are 17 total muscles that attach to the scapula which gives the brain many different options when it comes to function. One simple movement could have 8 different muscles that can complete that task, and it could use any variation in timing, amplitude, and coupling to complete that motion. Understanding that alone could give you a serious headache when trying to understand how people move.
Here's another picture of how many muscles attach to this floating bone that holds so much importance to how your shoulder moves.
The deeper muscles must set the foundation of stability of the joint so that the bigger, multi-joint muscles can complete the desired movement. When the deeper intrinsic muscles aren't functioning appropriately then the likelihood of stress around the joint increases significantly ie rotator cuff impingement.
This picture does a decent job of showing the silliness of potential movement solutions under varying degrees of freedom.
Wang, Z. et al. (2018). Structure Design And Analysis Of Kinematics Of An Upper-limbed Rehabilitation Robot. MATEC Web of Conferences. 10.1051/matecconf/201823202033. Retrieved from Researchgate
So now that we've gone over how many muscles need to help stabilize and mobilize the scapula alone and we've talked a little about how they must coordinate with the rest of the muscles throughout the body to perform a movement solution let's get into improving the movement adaptions that patients are developing when they should be cleared to return but still lack quality movement.
There are a few different subtypes that can be talked about in this article. Some examples are loose-jointed individuals that have had a labral or capsule tear due to hyperlaxity of the glenohumeral joint. These individuals are typically born with this hyperlaxity. Their rehab and transition to performance should be focused on stability. There are also examples of individuals that are incredibly stiff-jointed that over-leverage their mass and strength against the connective tissue structures that can't withstand the forces put on them. These individuals are for the most part stiffer movers and their rehab and return to performance is typically revolved around building up appropriate strength and then working to make sure the repaired shoulder isn't too stiff and can get into good positions. There is a similarity to the rehab approach for both of these subtypes of individuals. It revolves around the functional stability of the muscles that help guide the shoulder and its primary movers.
Source: Complete Anatomy
The Pectoralis Major, Pectoralis Minor, and Latissimus Dorsi are some of the biggest culprits to limiting shoulder range of motion post-surgery. They develop neurologic tension in an attempt to keep the shoulder moving but to also protect it from damage. It's the brain's use of the more readily available muscles. There will also be trigger points within the muscles which are commonly referred to as "knots in the muscles". These are there as a neurologic response to stabilize a poorly functioning joint complex.
Source: https://jay-jee.blogspot.com/2012/01/trigger-points.htmlStatic to Dynamic
Now that we've identified some of the muscle restriction issues causing a lack of "good" range of motion and proper layback we must talk about what to do about it. This is where all of your soft tissue work comes in. There are many forms of soft tissue that can be used to work on this tension. A few examples include:
Post Isometric Relaxation
Some of these styles I like to use more than others. I like locating where the trigger point patterns are and the direction and force vectors of the tension in certain parts of the muscle. It gives the practitioner a better understanding of the individual's preferred movement patterns. The biggest reason for doing any of these in my opinion is simply to create a neurologic response of reducing muscle tension. My theory is that this opens a window of better movement. Like most soft tissue treatments, the response returns back to its pre-treatment state within a week because the brain hasn't established a different movement pattern. It's within this window that you need to work to activate some of those smaller stabilizing muscles around the scapula like the lower trapezius and serratus anterior. These muscles were deconditioned during the timeline from injury to end-stage rehab. This approach to training the stabilizing muscles while turning off the bigger compensatory "movers" (listed above) is what's needed to make the lasting functional changes to allow someone to move well enough to perform like their normal self again.
How do we make this change? Well, like the majority of standard post-op surgery and return-to-performance therapy programs are designed, too much emphasis is put on open-chain progressions and strength training. Closed-chain exercises allow you to train more stability-based movements, which gives you the ability to reverse the origin and insertion of how the muscle fires. This trains better eccentric tone and joint centration so that the muscles can not only co-activate and balance muscle force around a joint but they can also do it dynamically with movement.
This picture gives an excellent example of the difference between open and closed chain movements.
The technique I use to accomplish this task is called Dynamic Neuromuscular Stabilization or DNS. DNS bases its movement principles on developmental kinesiology which is how babies learn to move through neurologic progressions and stages of development. I believe it's one of the best ways to help an athlete change their compensatory movement patterns. There are many different techniques and training methods that can be used that are closed-chain based, DNS is just what I've had the most success with.
The closed-chain stability training needs to bombard the nervous system in the window that the soft-tissue nervous tone is turned down from the manual therapy/stretching/muscle work etc. Continuous therapy of this nature is what's necessary to change the adaptions to function and movement that occurs after shoulder surgery. Too much open-chain training adds to these movement pattern compensations which result in an inability to achieve proper layback. I believe the standard and ideology amongst the medical and performance specialists need to/should change to really give the best likelihood of not only a successful return to play following surgery but also even better performance and optimization of movement.
Here is an example of how I used closed-chain stability for shoulder rehab. This is actually a later phase progression because it requires stability with added dynamic movement. This is much more difficult than it looks.
The shoulder is a tricky joint and we need to take a different approach when addressing the pillars of rehab to performance. I think shoulder recovery should have a much higher success rate. I hope this helps.