Effects of lumbosacral angles on development of low back pain

Objective: Low back pain [LBP] is an important health issue due the diagnosis and treatment expenses and loss of workforce it leads to. Biomechanical changes in the vertebral column caused by changes in the lumbosacral angles [LSAs] may lead to LBP. The purpose of this study was to assess body mass index [BMI] and LSAs in patients with LBP and investigate the association between LBP, LSAs and BMI. Methods: Lumbar lordotic angle [LLA], LSA, sacro-horizontal angle [SHA] and sacral inclination angle [SIA] were measured in 117 patients with chronic LBP and 85 healthy normal controls [HNCs] by means of lumbosacral radiography. In addition, association between LSAs, BMI and LBP was investigated. Results: There were no significant differences between patients and HNCs regarding LSAs and BMI. LLA was lower in male patients with LBP compared to male HNCs without LBP [p = 0.013]. In addition, SIA [p = 0.002] and BMI [p = 0.006] were higher in female patients with LBP compared to male patients with LBP. It was found that an increase in LLA increased the risk of having LPB by approximately 1.04-folds [ranging from 1.01 to 1.08; p = 0.045]. On the other hand, no association was found between LSAs and BMI. Conclusion: Changes in LSAs may cause LBP. An increase in LLA may be influential in increasing the risk of LBP. Therefore, measurement of LSAs may guide the physician who is to make clinical decisions in examination of patients with LBP.