If you’ve noticed one leg seems longer than the other — or you’ve been dealing with back pain, hip discomfort, or an uneven gait that doesn’t have an obvious cause — leg length discrepancy is worth ruling out. It’s a common but frequently overlooked condition, and understanding whether yours is structural or functional determines exactly how it should be treated.
Dr. Thomas French evaluates leg length discrepancy regularly at his Norwalk, CT practice, particularly in patients with chronic one-sided back pain, hip pain, or SI joint dysfunction that hasn’t responded to standard treatment.
Structural vs. Functional Leg Length Discrepancy — Why the Distinction Matters
This is the most important concept to understand, because the two types require completely different approaches.
Structural Leg Length Discrepancy
A structural discrepancy means one leg bone is genuinely, anatomically longer than the other — the femur, the tibia, or both. This can be congenital, or it can develop from a childhood fracture or growth plate injury that affected bone growth on one side. Structural discrepancies are measured with imaging and are a fixed, physical difference in bone length.
Importantly, a structural discrepancy that a patient has had their entire life is often something the body has already adapted to. The pelvis, spine, and surrounding muscles have developed their working balance around that difference. In these cases, aggressively “correcting” it — for example with an aggressive orthotic lift — can sometimes create new problems rather than solve them. This is a case where less intervention is often the right call, and any treatment should be conservative and closely monitored.
Functional Leg Length Discrepancy
A functional discrepancy is different — the bones are actually the same length, but muscular imbalance, pelvic misalignment, or joint dysfunction creates the appearance of one leg being shorter. A rotated or tilted pelvis, tight hip musculature on one side, or a restricted sacroiliac joint can all produce this apparent difference. This is the type most commonly seen in Dr. French’s practice, and it’s the type that responds directly and often significantly to chiropractic care — because the underlying cause is a correctable joint and muscle imbalance, not a fixed skeletal difference.
Distinguishing between these two types is the essential first step, because treating a structural discrepancy like a functional one — or vice versa — produces poor results.
How Uneven Leg Length Affects Your Spine
Whether structural or functional, a leg length imbalance changes how you stand, walk, and load your spine with every step. The body works to keep your head level and your eyes horizontal, and it does this by compensating up the kinetic chain — through the pelvis, the lumbar spine, and sometimes all the way to the shoulders and neck.
Over time, this compensation pattern creates a predictable set of problems: a lateral pelvic tilt, compensatory curvature in the lumbar spine, asymmetric loading on the SI joints, and uneven wear on the hip and knee joints on the longer-functioning side. Chronic one-sided back pain, hip pain, and even shoulder or neck asymmetry can all trace back to an underlying leg length imbalance that’s never been identified. Learn more about back pain treatment →
How Dr. French Diagnoses Leg Length Discrepancy
The evaluation starts with a physical assessment — comparing leg length with the patient lying face down (prone), checking the position and level of the iliac crests (the top of the pelvic bones) while standing, and assessing pelvic rotation and tilt. This clinical exam often reveals whether the discrepancy is likely structural or functional before any imaging is needed.
A simple self-check at home: stand in front of a mirror and compare the height of your hip bones on each side (your iliac crests). A visible difference is worth having evaluated. For confirmed or significant discrepancies, standing X-ray measurement provides a precise, objective measurement.
How Chiropractic Treats Functional Leg Length Discrepancy
For functional discrepancies caused by pelvic misalignment or muscle imbalance, chiropractic adjustment addresses the actual cause directly. Realigning a rotated or restricted pelvis, adjusting the SI joints, and releasing the muscle tension that’s holding the pelvis out of position often resolves the apparent leg length difference — and the back or hip pain that came with it — without any need for orthotics or lifts.
Theragun percussion therapy addresses the chronically tight hip flexors, piriformis, and quadratus lumborum that commonly accompany this pattern. Specific exercises targeting the muscle imbalance help maintain the correction between visits and prevent the pattern from recurring.
When Orthotics or Shoe Lifts Are Appropriate
For confirmed structural discrepancies — particularly smaller differences that the body hasn’t fully compensated for, or larger discrepancies causing significant symptoms — a shoe insert or heel lift can help rebalance the pelvis during standing and walking. This is typically a conservative, gradual approach rather than an aggressive full correction, since sudden significant changes in leg length can create new compensation problems.
For discrepancies the body has lived with and adapted to over many years, changing that balance isn’t always advisable — sometimes leaving a stable, adapted pattern alone is the better clinical choice than attempting to “fix” something the body has already successfully compensated for.
Related Conditions
Leg length discrepancy often overlaps with or contributes to:
- Sciatica — asymmetric pelvic loading can compress the sciatic nerve on one side
- SI Joint Dysfunction — the SI joints bear the brunt of pelvic imbalance
- Scoliosis — significant leg length discrepancy can contribute to functional scoliotic curves, distinct from structural adolescent scoliosis
- Back Pain — chronic one-sided back pain is one of the most common presentations
H2: Frequently Asked Questions About Leg Length Discrepancy
A simple check: stand in front of a mirror and compare the height of your iliac crests (the top of your hip bones on each side). A visible difference suggests a leg length discrepancy worth having professionally evaluated. Chiropractic assessment can determine whether the difference is structural (an actual bone length difference) or functional (caused by pelvic or muscular imbalance).
Yes. A leg length imbalance changes how the pelvis and spine load with every step, often producing compensatory pelvic tilt and lumbar curvature. Over time this leads to chronic one-sided back pain, hip discomfort, and uneven joint wear. Identifying and addressing the underlying cause — particularly if it’s functional rather than structural — often resolves the associated pain.
A structural discrepancy means one leg bone is genuinely longer than the other — a fixed anatomical difference. A functional discrepancy means the bones are the same length, but pelvic misalignment or muscle imbalance creates the appearance of unevenness. This distinction matters because functional discrepancies respond well to chiropractic correction, while structural discrepancies require a different, more conservative approach.
It depends on the type and severity. Functional discrepancies caused by pelvic or muscular imbalance are best addressed by correcting the underlying cause through chiropractic care, not by compensating with a lift. Confirmed structural discrepancies, particularly larger ones, may benefit from a gradual, conservative shoe insert or heel lift. Long-standing discrepancies the body has already adapted to sometimes shouldn’t be altered at all.
For functional leg length discrepancy caused by pelvic misalignment or muscle imbalance, yes — chiropractic adjustment directly addresses the cause and often resolves the apparent difference along with associated pain. For structural discrepancies where the bones are genuinely different lengths, chiropractic can’t change bone length, but it can address the secondary muscle and joint compensation patterns and help determine whether an orthotic approach is appropriate.
Significant leg length discrepancy can contribute to a functional scoliotic curve — the spine curves to compensate for the pelvic tilt. This is different from adolescent idiopathic scoliosis, which is structural and unrelated to leg length. Distinguishing between the two is part of a thorough evaluation. Learn more about scoliosis →
Schedule an Evaluation in Norwalk, CT
If you suspect a leg length discrepancy or you’re dealing with chronic one-sided back or hip pain that hasn’t responded to other treatment, Dr. French’s Norwalk, CT office offers a thorough evaluation to identify the cause and the right approach.
Call (203) 939-9700 or book online. Located at 148 East Avenue, Suite 1D, Norwalk, CT 06851 — I-95 Exit 16, free parking.
Serving patients from Norwalk, Westport, Wilton, Darien, New Canaan, Weston, and Stamford.