Regional interdependence is a concept that I explain on a daily basis. Still, I hardly call it that unless I speak with another physical therapist or an excellent strength and conditioningPhysical Therapist in Alexandria Virginia Assisting Patient With Movement Economy pro. Clients come to our clinic to get our take on why they hurt and what might be causing their pain.

After all of our questioning, measuring, observing, and differential diagnosis, we come to the functional diagnosis.

This is usually in language that most who seek our help have heard before. It sounds like, “You have a Grade I strain of your right hip adductor muscles, specifically, your adductor magnus,” or something like that. Maybe the person came into us with a “piriformis syndrome” or “herniated disc” diagnosis from their specialist. Even better, maybe Google told them that they have “osteoarthritis” and that there is no cure.

Whatever the final answer is, it’s rare that there isn’t an explanation for “WHY” any of this pain or restricted movement came about, and this is where “regional interdependence” was born.

Here, I want to outline a simple-to-understand concept called Movement Economics. This: 

  1. Makes understanding and explaining regional interdependence easier
  2. Serves as a platform for understanding how strength and conditioning and injury prevention/rehabilitation go hand in hand
  3. Explains how physical therapists and strength and conditioning pros can work together to enhance the movement and performance of their clients

Movement Econ 101: The Basics

  • All movement has a cost; we use ‘movement funds’ to pay for any and all coordinated and purposeful movement.
  • We each have a ‘movement account’ which allows us to move with varying intensity and volume.
  • To increase the size, make deposits into your ‘movement account,’ thereby increasing your work capacity; you can increase your strength, coordination, skill level, mobility, endurance, etc.
  • Those with low ‘movement account’ balances are typically weaker, less mobile, less agile, less coordinated, less skilled, etc.
  • If you attempt a movement that comes at too high a ‘cost,’ you risk ‘overdrawing your movement account.’ This is an acute injury or pain state.
  • Movements that are done too repetitively can have the same impact. Even if a movement has a low cost, there is no such thing as an infinite ‘movement account,’ you become at risk when a less ‘expensive’ movement is done too much.

A Brief Case Study

To best understand this concept, we must consider a specific movement. The movement we are discussing here will be low-level and easy to perform. As you will see, even the simplest movements require many steps and systems working properly for the movement to happen without any ‘issues.’ If there is a Movement Econ issue, we will see system corrections and compensation that will make simple movements more complex, increasing their movement cost and eventually overdrawing the movement account.

The movement under examination here ascends one 7″ ADA-compliant stair with your left foot. Here, I will provide a brief case study and the regional interdependence/Movement Econ explanation for why this client’s pain began from a small change that decreased her ability to ascend the stairs, and now she presents to our clinic with left-sided back and hip pain diagnosed by a physician as “lumbago” (smh).

For the purposes of this example, we will lay down some assumptions and build the case. These are only estimates of real requirements for our mobility example. While the exact figures may vary from person to person by a small margin, the point will remain the same. Climbing one 7″ ADA compliant stair with your left foot REQUIRES:

  • 15 degrees of active left ankle dorsiflexion
  • 90 degrees of left knee flexion
  • 80 degrees of active left hip flexion
  • near full strength of the right hip abductor muscles
  • near full strength of right-sided trunk muscles
  • near full strength of the left hip extensor muscles
  • near full strength and mobility of the spine for extension
  • at least 0 degrees of available hip extension of the right hip

While this might look like a long list of requirements for something as simple as climbing one stair with one foot, it’s far from complete. For the case we are examining here, it’s more than enough to paint the picture.

Our client presents to us with pain (an overdrawn movement account) in her left-sided lower back with some mild radiation to her sacroiliac area and a bit lower into what she senses as her ‘sits bone’ on the left near her glute max. If we only heard this complaint and evaluated her, we probably would have come to the same conclusion as if we had taken the “Movement Econ” mindset. Her paraspinal muscle strain, likely her left quadratus lumborum (QL), would be found with movement-based tests and easy palpation. We’d teach her what she needed to know about muscle tissue healing. We’d likely supervise her and prescribe some trunk muscle mobility and strengthening work so that her QL was better capable when it healed. Slam dunk!

What if we mention that upon FULL examination, it was discovered that she only had 3 degrees of active dorsiflexion of her left ankle? Does this change how you will treat her QL strain, or how long it will take for her back and hip pain to resolve?? Probably not. However, what changes is whether you will see her AGAIN in your clinic for the same thing. Here is where an intimate understanding of Movement Economy comes in very handy.

Our client cannot actively dorsiflex her left ankle, given the effort of the surrounding muscles and accessibility of the joint to do the movement we are examining (decreased movement increased movement costs). To clear her foot to the next step, she must increase the work she does to flex her left hip (spend more movement funds), let’s say to 95 degrees. It is only a matter of time, or volume in this case, before her left hip flexor muscles become fatigued (increased movement costs = closer to overdrawing the movement account). After all, those muscles already have their task to perform (normal movement costs). The extra workload, while not a lot by itself (‘low relative movement cost’), is added to the work that must be done, making the movement less efficient and ‘more costly.’

The left hip flexor muscles take on the new movement cost, and we continue climbing stairs. The hip flexor muscles are near failure (overdrawing the movement account). This might be cumulative over many stairs during a week or month, but the scenario is the same; we are further into movement account debt!

How can we clear that foot to the next step if we miss ankle dorsiflexion AND hip flexion? One way would be to bend the left side! Of course, this is done in the closed chain on the right leg, so here is where the QL got involved. If one were to examine this movement, we would find that the QLs would “normally” work in conjunction with the right hip abductor muscles to stabilize the trunk and keep us mainly moving forward without too much unnecessary side bending. In this scenario, the left QL has its role (normal movement cost) AND an additional role of clearing the hip for the fatigued hip flexors (increased movement cost), which are fatigued because we don’t have enough left ankle dorsiflexion!

And that’s it! We examined the client, fully understanding the Movement Econ picture in front of us. We found areas of poor movement economy. Addressed the acute pain or restriction, as well as the likely reason this all started, and now we will not have the dubious pleasure of treating her again for the same complaint.

Movement Economics Aids Everyday Clinical Decision-Making

The above case was an example based on a true patient experience. The pain and restriction were the results of a low-level movement econ issue combined with a high volume. Now, envision the case of the 17-year-old elite-level, highly competitive baseball pitcher that we examined and treated in the very next hour who came to us with dominant shoulder pain. Elite-level throwing is one of the most violent single sports movements we know (VERY HIGH movement cost). Where did we start our search for answers, and where did we end up? Suppose Movement Economics is the foundation that guides some of your clinical decision-making. In that case, you are already on the right track to having the pleasure of seeing this client more often on the baseball diamond than you see him in your clinic, just as we like it.

Dr. Carlos J Berio, PT, DPT, MS, CSCS, CMTPT is a licensed Doctor of Physical Therapy, Certified Strength and Conditioning Specialist, and a Certified Myofascial Trigger Point Therapist. In addition, he holds a Master’s Degree in Clinical Exercise Physiology. He has treated high school, collegiate, recreational, and professional athletes of various sports, including baseball, softball, football, hockey, tennis, swimming, golf, and martial arts. His experience as a collegiate and semi-professional athlete, as well as a professional baseball coach, make him a sought-after resource among elite-level athletes on the field and in the training room. The concept of ‘all the way well’ in his work as a physical therapist and fitness professional is what continues to drive Dr. Berio to be the best movement specialist there is.

Carlos remains active in several sports and is an avid agility training, powerlifting, and adventure race runner. He is an advocate for his patients, clients, and his fellow PT colleagues. He can be reached at [email protected].