Why Your Foot Might Explain Your Back Pain
One of the more frustrating things a patient hears in a clinical setting is "your back hurts, so we're going to treat your back." It's intuitive, and sometimes it's correct. But there's a body of work in musculoskeletal medicine that says, fairly often, the place that hurts isn't the place that needs the most attention — and the foot is a recurring example.
The clinical concept is called regional interdependence: the idea that musculoskeletal complaints in one body region can be driven, maintained, or aggravated by impairments in another, sometimes distant, region1. It's a foundational idea in modern manual therapy and movement-based rehab, and it's one of the reasons our assessments at Boreal Spine & Sport always extend well beyond the painful site.
The big toe and the low back — a worked example
Consider a runner with a recurring low back ache that flares up at the end of long runs. The standard assessment finds tight hamstrings, a tight thoracic spine, maybe some asymmetry in hip rotation. Treatment of those areas helps for a few weeks, then the pain returns. What's often missed: the runner has limited dorsiflexion at the first metatarsophalangeal joint — the big toe — on the same side.
The big toe needs about 60° of dorsiflexion for a normal terminal stance phase of gait2. When it doesn't extend properly, the body finds the motion somewhere else — often by collapsing the medial longitudinal arch, internally rotating the tibia, then the femur, and finally creating a small but repeated rotational demand at the lumbar spine. Over miles of running, that becomes the chronic low back ache.
Address the big-toe restriction, restore the motion, and the chain above it often quiets down. We've seen this story play out repeatedly with runners coming through the clinic, particularly in the spring as mileage ramps up and small mechanical issues start to compound.
Why this isn't just a chiropractic talking point
Regional interdependence has been studied across multiple regions. The cervicothoracic-shoulder relationship is one of the strongest examples — patients with shoulder pain consistently improve more when thoracic spine mobility is addressed alongside the shoulder, even when their thoracic spine isn't symptomatic3. Hip mobility and stability deficits are linked to knee pain and low back pain4. Ankle dorsiflexion limitation predicts knee injury risk in jumping athletes5.
The pattern across the literature is consistent: musculoskeletal regions don't operate in isolation, and treating only the painful site frequently produces incomplete or short-lived improvement.
What this changes about an exam
If you come into our clinic with low back pain, we're going to look at your hips. We're also going to look at your thoracic spine, your feet, and how you transfer load through gait. This isn't because we don't believe the back is the problem — it's because the back is rarely the only problem, and the most durable plans address the chain rather than the link that happens to hurt.
This same logic shows up in our pieces on thoracic mobility and shoulder pain — the painful site is usually telling part of the story, not the whole one.
Where this can be overdone
Regional interdependence isn't a license to treat everything. There are plenty of low backs that are simply a low-back problem, and there are plenty of shoulders that respond beautifully to a focused shoulder-only plan. The clinical art is in the assessment — finding the impairments that genuinely matter, not creating a list of "things that look off" and chasing all of them.
Done well, this approach makes treatment more efficient, not less. A few targeted interventions in the right places usually outperform a long list of generic exercises aimed at the painful site.
The takeaway
If you've been treating one region for months and it isn't holding, the answer might not be a different technique applied to the same region. It might be a careful look at the joints above and below it. That's the lens we use here in Winnipeg, and it's part of why our plans tend to look different than what people have tried before.
References
- Sueki DG, Cleland JA, Wainner RS. A regional interdependence model of musculoskeletal dysfunction: research, mechanisms, and clinical implications. J Man Manip Ther. 2013;21(2):90–102.
- Nawoczenski DA, Baumhauer JF, Umberger BR. Relationship between clinical measurements and motion of the first metatarsophalangeal joint during gait. J Bone Joint Surg Am. 1999;81(3):370–376.
- Mintken PE, Cleland JA, Carpenter KJ, Bieniek ML, Keirns M, Whitman JM. Some factors predict successful short-term outcomes in individuals with shoulder pain receiving cervicothoracic manipulation: a single-arm trial. Phys Ther. 2010;90(1):26–42.
- Powers CM. The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: a theoretical perspective. J Orthop Sports Phys Ther. 2003;33(11):639–646.
- Fong CM, Blackburn JT, Norcross MF, McGrath M, Padua DA. Ankle-dorsiflexion range of motion and landing biomechanics. J Athl Train. 2011;46(1):5–10.
Author: Dr. Michael Minenna D.C., B.Sc., SFMA, FMS — Boreal Spine & Sport, Winnipeg, Manitoba.