Lumbar lordotic change and its fulcrum in low back pain disorders: Radiographic evaluation

Globally, low back pain (LBP) is now the leading cause of disability. Patients often have lumbar spine motion dysfunction (motion decrease/increase), and this may affect the lumbar lordosis (LL). Though the relationship between LL and LBP is controversial, it has immense clinical significance, because it serves as the basis of therapeutic exercises for treating and preventing LBP. An angular measure of LL that consistently detects even a small lordotic change (LC) would be considered reliable.

The consistency of some radiographic angles in detecting LC in a potential LBP disorder was evaluated, and LC fulcrum deducted.

In both normal (control) and spondylotic (test) lateral lumbosacral radiographs of both genders, LL was retrospectively measured using the following angular measures and sample sizes: Lumbosacral angle (LSA, 125), Lumbosacral joint angle (LSJA, 115), Cobb angle (118), and Tangential radiologic assessment of lumbar lordosis (TRALL) angle (101). The angles' consistency in detecting intra-gender LC between control versus test was evaluated. The intervertebral disc (IVD) that sub-tended the most consistent angle represents the LC fulcrum. All cases were ≥17 years of age. Data was analyzed with IBM SPSS Statistics 23.0 (NY, USA); P < 0.05 was considered statistically significant.

LSJA detected slight intra-gender LC in both genders, LSA in males only, Cobb and TRALL angles in none. The IVD of L5/S1 sub-tended the LSJA and therefore represents the LC fulcrum.

LSJA is a reliable measure of lumbar LC in physical therapy of LBP, especially, the non-specific LBP disorders.