The effect of leg length on back pain: a classic test
Eight pages on PainSci cite Grundy 1984: 1. The Complete Guide to Trigger Points & Myofascial Pain 2. Does Posture Matter? 3. The Complete Guide to IT Band Syndrome 4. The Complete Guide to Low Back Pain 5. The Not-So-Humble Healer 6. Are Orthotics Worth It? 7. Your Back Is Not Out of Alignment 8. Reading Guide for Professionals
PainSci commentary on Grundy 1984: ?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided wherever possible.
This classic, elegant experiment found no connection between leg length and back pain. Like most of the really good science experiments, it has that MythBusters attitude: “why don’t we just check that assumption?” Researchers measured leg lengths, looking for differences in “lower limb length and other disproportion at or around the sacroiliac joints” and found no association with low back pain. “Chronic back pain is thus unlikely to be part of the short-leg syndrome.” Other studies since have backed this up, but this simple old paper remains a favourite.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
In a case-control study, in which a specially designed questionnaire and a ‘locating jig’ were used to investigate the association between difference in lower limb length and other disproportion at or around the sacroiliac joints and the existence of chronic low back pain, no association was found. Chronic back pain is thus unlikely to be part of the short-leg syndrome.
related content
- “Relationship between mechanical factors and incidence of low back pain,” Nourbakhsh et al, Journal of Orthopaedic & Sports Physical Therapy, 2002.
- “Leg-length discrepancy is associated with low back pain among those who must stand while working,” Rannisto et al, BMC Musculoskeletal Disorders, 2015.
- “Comparison of supine and prone methods of leg length inequality assessment,” Cooperstein et al, J Chiropr Med, 2017.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Long-Term Effects of Repeated Injections of Local Anesthetic With or Without Corticosteroid for Lumbar Spinal Stenosis: A Randomized Trial. Friedly 2017 Arch Phys Med Rehabil.
- Cannabis-based medicines for chronic neuropathic pain in adults. Ateş 2026 Cochrane Database Syst Rev.
- Effect of exercise on depression and anxiety symptoms: systematic umbrella review with meta-meta-analysis. Munro 2026 Br J Sports Med.
- Optimizing elastic band resistance training for Metabolic Syndrome components in older adults: A systematic review, meta-analysis, and meta-regression of randomized controlled trials. Saez-Berlanga 2026 Arch Phys Med Rehabil.
- Biomechanical insights into Achilles tendinopathy risk and protection in runners: a large prospective study 4HAIE. Jandacka 2026 Br J Sports Med.