What Is Regional Interdependence — And How Does It Relate to Your Back Pain?

A patient comes in with low back pain. I check their hip range of motion. Almost every time, someone asks the same reasonable question: "why are you looking at my hip? My back is what hurts." It's a good question, and the honest answer is a real, formally described model in physiotherapy called regional interdependence.

What regional interdependence actually is

The term was formalised in 2007 by Wainner and colleagues in the Journal of Orthopaedic & Sports Physical Therapy, who defined it as the concept that "seemingly unrelated impairments in a remote anatomical region may contribute to, or be associated with, the patient's primary complaint."¹ In 2013, Sueki, Cleland and Wainner expanded it into a broader model — not just joints and muscles talking to each other mechanically, but a genuinely interconnected system worth examining as a whole rather than one sore segment in isolation.²

In plain terms: your back doesn't work in isolation. It sits between your hips and your ribcage, and how those regions move — or don't — changes the load your lumbar spine has to absorb. A proper back assessment looks at the whole chain, not just the part that hurts.

The best-evidenced example: your hip

Of all the regions studied alongside the low back, the hip has the most consistent evidence behind it. A study of professional golfers found that low back pain was associated with reduced hip and lower-back range of motion together, not the back alone.³ A separate study comparing active adults with chronic low back pain against pain-free controls found a genuinely large difference in passive hip extension — roughly 11 degrees less on average in the group with back pain, with no equivalent difference in hip rotation.⁴ That's specific: it's not "hips matter generally," it's a particular movement, in a particular direction, showing up again and again in people with back pain.

The logic isn't hard to follow. If your hip can't extend properly — the movement your leg makes swinging behind you when you walk, or straightening up from a forward bend — something else has to make up that range. Often, it's your lumbar spine picking up the slack, moving more than it's really designed to on every stride and every bend, day after day.

Treatment-level evidence for this is still early, and worth being honest about: a small case series found that hip mobilisation combined with exercise produced a short-term improvement in a group with chronic low back pain.⁵ A case series has no control group, so on its own it can't prove hip work caused the improvement. It's a reasonable signal, not proof — which is a fair description of where a lot of regional interdependence treatment research currently sits.

What actually predicts back pain developing

Most of the research above compares people who already have back pain to people who don't — useful, but it can't tell you which came first. A 2017 systematic review took a stronger approach, pooling only prospective studies that measured people before any back pain existed and then followed them over time. It found that restricted side-bending range of motion, reduced lumbar lordosis, and — notably — reduced hamstring flexibility each predicted who went on to develop low back pain.⁶

That's a genuinely different, stronger claim than a correlation snapshot: tight hamstrings measured today predicted back pain that hadn't happened yet. It's exactly the kind of finding regional interdependence would predict, and it's why a proper assessment for back pain often ends up including a look at hamstring length that has nothing to do with checking a box — it's checking a documented risk factor.

Not everything is connected to everything

This is the part I think matters most, and it's the part that gets lost when regional interdependence gets turned into a slogan. It is not a licence to treat every joint in the body every time someone's back hurts. A 2014 systematic review and meta-analysis comparing lumbo-pelvic movement in people with and without back pain found real, consistent differences in lumbar movement patterns — but the picture for pelvic and thoracic movement was far less consistent across studies.⁷

In other words: the hip link is real and reasonably consistent. Some other proposed links are weaker, or depend heavily on the individual. A good assessment uses regional interdependence as a reason to check more broadly than the sore spot — not as an excuse to invent a story connecting every part of the body to your back pain regardless of what's actually found on examination.

What this means when you come in with back pain

It's part of why a thorough initial assessment for back pain takes longer than checking the sore segment and calling it done. We're looking at hip extension range specifically, hamstring length, and how your lumbar spine actually moves under load — not because it's thorough for its own sake, but because each of those has a real, published, sometimes predictive relationship with back pain outcomes.

It's also, incidentally, the same reasoning behind why we screen glute function as part of assessing lower limb and hip mechanics more broadly — the hip doesn't just extend on its own; the muscles controlling it matter just as much as the raw range of motion.

Hugo Dreux

Senior Physiotherapist · Move Physiotherapy & Fitness

BSc (Hons) Physiotherapy, University of Birmingham — First Class Honours and the Clinical Education Prize. Over three years' NHS experience before joining Move. Special clinical interest in spinal conditions, including back and neck pain.