Today marks the third and final installment of Eric Schoenberg’s series on thoracic mobility drills – and whether or not they’re indicated. In case you missed them, be sure to check out Part 1 and Part 2.

In the final piece of this series, I want to tie things together with a few foundational concepts that we use in the daily management of our athletes and emphasize in our Elite Baseball Mentorships.

Eric C. has written about the concept of relative stiffness on this blog on numerous occasions. So, feel free to refer back to his articles for more background information. Relative stiffness or relative flexibility was introduced to me by Shirley Sahrmann and the incredible faculty at Washington University in St. Louis. This is a pillar of their Movement System Impairment model.

Today, I am going to discuss how relative flexibility impacts the thoracic spine and shed some more light on why T-spine extension work is not always necessary in the baseball athlete.

Relative flexibility describes the relationship of how the amount of stiffness (or tension) in one area of soft tissue (muscles, ligaments, tendons, etc.) results in compensatory movement at an adjoining joint that is controlled by less stiffness. This relationship can change (positively or negatively) based on the exercises we choose and the manner in which we perform them.

There are countless examples of relative stiffness in the body. One of the most common examples that we see involves the lumbar spine. If the lats are stiffer than the anterior core, then the athlete will be more prone to an extended posture. The athlete will compensate with lumbar extension with overhead activity. The video that I included in part 2 of this series is a good example:

In this video, Lats, lumbar extensors > (stiffer than) Anterior Core = Lumbar extension tendency.

Note: Clearly, there is a lot more involved (fascia, ligaments, structural issues, motor control, relative position of adjacent joints, etc.) than just this simple math problem, but for the scope of this article, we will leave it at this. This example is fairly straightforward and I think we are all on the same page here. We would not program activities that would further encourage lumbar extension and drive the improper recruitment and motor pattern.

In this case, we know that simply “stretching” or foam rolling the lats will not work in isolation. We need to go ahead and “stiffen” the anterior core, while at the same time, downregulating the overuse of the lats. We often will do this by using exericses that encourage a neutral alignment with overhead activity (i.e. wall slides, back to wall shoulder flexion) as well as limiting the amount of carrying by our sides (e.g. deadlifts, dumbbell lunges, farmer’s walks, etc.) and instead, focusing on options like bottoms-up kettlebell carries, landmine presses, and goblet variations.

In the case of someone that is in too much thoracic extension (or relative thoracic flexion), though, things can get a little more confusing. The athlete will have increased stiffness of the thoracic extensors vs. flexors: Thoracic Extensors > (stiffer than) Thoracic Flexors = Thoracic extension tendency.

However, we often see the emphasis remain on bench T-spine mobs, quadruped extension/rotations, and side-lying windmill variations? This results in two problems:

1. The athlete will actually become hypermobile (segmentally) and develop a local stability issue. (inverted U-curve)
2. The athlete has difficulty “getting out of extension” due to increased relative stiffness of the thoracic extensors, lats, and scapulothoracic musculature.

This inability to properly flex the spine at ball release can result in a decrease in the required scapular upward rotation and elevation to maintain proper scapulohumeral and glenohumeral joint congruency. This is a fancy way of saying that if your upper back isn’t positioned correctly, the ball won’t sit flush with the socket. This process can contribute to some of the shoulder and elbow pathologies that we so commonly see in the throwing population.

There is one more point that needs to be addressed to complete this series – and that is the role of the rectus abdominus in thoracic spine mobility. In this case, the athlete will present in too much thoracic flexion and may appear as though they would benefit from T-spine extension mobility drills. However, this athlete will not benefit from these exercises unless we appreciate the following point.

When we cue an athlete to limit his extension or “rib flare” we often say “ribs down”. This seems like a relatively benign cue to help promote a neutral spine and pelvic orientation. However, we must be sure that the athlete is able to properly recruit external obliques (often with lower level exercises such as back to wall shoulder flexion or a dead bug variation) to help achieve this movement correction.

The reason for this is that increased stiffness of rectus abdominus (dominance) limits ability of T-spine to move out of flexion (or neutral). Using our relative stiffness example from before, if: Rectus abdominus > (stiffer than) Thoracic Extensors = Thoracic Flexion Tendency.

Therefore, if an athlete is actually is in too much flexion… i.e. sway back (most commonly – posterior tilt and lumbar extension – hanging on rectus as their anti-gravity muscle), he will have a very difficult time getting out of flexion. This occurs regardless of how many T-spine drills we prescribe. This is akin to stretching rectus femoris when someone is stuck in a faulty thoracic and lumbopelvic position.

The best approach in our case above is to “allow” t-spine mobility (extension) to occur by decreasing rectus dominance and getting someone out of T-spine flexion. I am all for cuing the ribs down and establishing alignment, but HOW we get an athlete to do this is of the utmost importance. The main point here is forcing T-spine extension in the presence of increased relative stiffness of rectus abdominus is not going to give us results. In other words, weak external obliques will result in rectus overuse and thoracic “immobility” regardless of how many T-spine mobility drills we include in our programs.

To summarize, this is a very important (and difficult) concept that – like everything else – requires a trained eye and an individualized approach. If an athlete has too much thoracic and lumbar extension, this can result in scapular depression and downward rotation via, among others things, excessive lat dominance, which leads to a lot of our shoulder and elbow dysfunction. On the other hand, too little thoracic extension results in scapular anterior tilt and decreased glenohumeral external rotation (“lay back”), also resulting in dysfunction and pathology.

As a quick review, you want to be able to answer the following questions before prescribing T-Spine extension exercises:

• Is there a lack of T-spine extension (or rotation). If not, then why prescribe T-spine extension mobility drills?
• Where is the extension coming from (upper or lower T-spine, L-spine, C-spine)?
• Is the athlete already at end-range extension and if so, is our attempt to “gain” extension at end-range creating unwanted motion elsewhere? (hypermobility)
• Lastly, if an athlete presents with mal-alignment (too much thoracic extension or thoracic flexion): first, identify it, then determine why this is happening prior to simply prescribing a bunch of mobility exercises.

Conclusion

This point, along with many others, is a main reason why we chose to develop the Elite Baseball Mentorship program. As we gather together in these groups, many conventionally accepted ideas and concepts are questioned and explored and the demand for proof (whether it be from research or experience) requires us all to think more critically. Most importantly, with baseball-related injuries continuing to rise, this allows us to question the status quo of generally accepted baseball-specific protocols. Ultimately, this collaboration allows us all to advance the bar and develop a better opportunity for our athletes to meet their goals through better health and performance.

Also, if you are interested in more information like this, we would love to see you at one of our Elite Baseball Mentorships. We’ll be hosting these events in June, October, and December of 2014. Please click here for more information.

Author’s Note: I would like to thank Michele Ionno, MS, SPT (Wash U Program in Physical Therapy) for his contribution to the 3^rd phase of this blog series.

About the Author

Eric Schoenberg, MSPT, CSCS is co-owner of Momentum Physical Therapy, located in Milford, MA. He can be reached at eric@momentumpt.com.