Regional Interdependence
What does it mean and why is it important for optimal movement?
The term “regional interdependence” has been becoming more and more relevant in the field of rehabilitation over the past several years. In the rehab and movement science world, we know it as the relationship of how each joint affects its closest partner, and subsequently up/down the kinematic chain. How any inefficiencies through the entire chain of movement can lead to break down over time. The easiest way for me to summarize it for everyone is like this:
Think about your best overhead deep squat position you can get into. Does your upper body tilt forward like a lawn chair folding up the deeper you go down? Does your butt stick out the lower you’re getting? Why do you think that is?
The dreaded answer: “It depends…” absolutely applies to this situation. Is that squat depth limited due to an ankle mobility limitation? Is that upper trunk lean happening because of a “weak core”? The truth is – we don’t know, but a good Physical Therapist should be able to find out.
Segments on segments, on segments
When I was first learning about human movement concepts, one image in particular helped simplify things down for me:
From the ground up, our bodies are built up by stable joints, connected to mobile joints, in an alternating fashion, to produce movement. Much like any other system of interconnected parts, if any part/link is not working properly in its designed fashion - mechanical breakdown will occur somewhere along that chain!
That doesn’t necessarily mean the break down will happen right at that particular joint though. The value of doing a full body movement screen and assessment cannot be understated - looking at the whole picture, rather than just the site of the symptoms, is crucial to identifying human movement dysfunction, and drives decisions about how to treat the dysfunctional movement pattern.
Putting the pieces together
I view full body movement as a coordinated sequencing of specific muscle actions that cause joints and limbs to move in a desired fashion. The term “coordinated” is crucial here, because timing of specific actions is incredibly important to moving the right way. That’s why I can’t stress it enough for clinicians everywhere – if you’re only looking at the site of the symptoms, you need to rethink your clinical reasoning skills. Someone may be suffering from lower back pain, does that mean “their hamstrings are tight?”
Side note – if any one ever tells you or someone you love that their backs hurt for that sole reason, please refer them back to this blog post (thanks in advance).
Someone might be having lower back pain for a ton of reasons, but most of the time, the hamstring “tightness” is probably a symptom of overactive stimulation from the nervous system, accompanied with an overall lack of generalized lumbo-pelvic stability/coordination over a significant amount of time that causes hamstrings to “tighten” up. With the proper techniques and movement pattern sequencing, “tight” hamstrings all of a sudden become reactive, powerful, and adaptable to the circumstances at hand.
Looking at movement as a compound collection of coordinated joint movements is the best advice I can give to someone who’s genuinely interested in observing movement patterns. In the case of regional interdependence, I want you to appreciate how lacking sufficient ankle mobility will limit someone’s ability to squat down to pick something up. Which could cause their knee to collapse in a little bit. Which could then cause their pelvis to shift forwards and throw off their alignment a little bit more. Which then could then effectively “turn off” any legitimate chance of lateral chain stabilizer (glutes, obliques, etc.) contributions. Which could then ultimately cause a significant increase to the demands of the lower back musculature and increase tone/muscle strain. Imagine how many times in your life you picked up something off the ground and had all those little tiny movement issues happening each and every time. Maybe your back isn’t hurting because you have tight hamstrings; maybe your back is hurting because you have limited ankle mobility and whenever you lift down to pick something up, you’re causing excessive strain on your lower back muscles. How will we ever really know? We won’t - until we take a look and diagnose what’s going on!
Do you see what I’m saying? Just because someone’s back is hurting, doesn’t mean you only look at their back (or hamstrings). Look at the whole thing – don’t get caught up on symptoms! So often, especially early on in our careers, clinicians chase the symptoms. I chase the source. Getting to the root of the problem will subsequently start driving changes in function first, and eventually down the road, less pain over time. Once you can appreciate and understand the concept of regional interdependence, that’s where we start seeing results.
