Yoshihito Sakai, Shiro Imagama, Zenya Ito, Norimitsu Wakao and Yukihiro Matsuyama
Objectives: To evaluate therapeutic exercise-induced hemodynamic changes in patients with flexion- and extension-provoked low back pain (LBP).
Methods: Men with LBP (n=106) were divided into 2 groups: flexion-provoked LBP (n=61) and extensionprovoked LBP (n=45). The Japanese Orthopaedic Association (JOA) score, Visual Analogue Scale (VAS), SF-36 and intramuscular oxygenation measured by near-infrared spectroscopy on the paraspinal muscle during lumbar extension and flexion were evaluated at 2 and 4 weeks.
Results: Deoxygenated hemoglobin during lumbar flexion was significantly lower in flexion-provoked LBP than in extension-provoked LBP. VAS and the SF-36 domains of physical functioning, role physical, bodily pain were significantly improved in the flexion-provoked LBP group. Oxygenated hemoglobin during lumbar extension was increased significantly in the flexion-provoked LBP group. Flexion-provoked LBP patients who exhibited favorable effects from therapeutic exercise also showed better lumbar muscle oxygenation after exercise.
Conclusions: A stretching mechanism in the posterior lumbar elements appeared to have a promising therapeutic effect on extension-provoked LBP. Although LBP attributed to hypoperfusion and oxygenation is involved in flexionprovoked LBP, therapeutic exercise was effective in only 50% of these patients. Evaluating muscle blood flow in flexion-provoked LBP patients is critical for improving the therapeutic effect in these subjects.