Radiographic Investigation of Lumbar Vertebrae in Patients with Flexion and Extension Movement Disorder Syndrome.

Objectives: The kinesiopathology model is a new rehabilitation model classifying, evaluating, and treating patients with non-specific back pain. Sahrmann proposed this model based on movement disorder syndromes. The present cross-sectional study aimed to evaluate the radiograph of the linear and angular displacement of the lumbar spine in patients with lumbar flexion impairment syndrome (LFIS) and lumbar extension impairment syndrome (LEIS). Methods: In this study, 50 adults aged 18-46 years were enrolled, including 25 patients with LFIS and 25 with LEIS. The eligible participants were referred to the radiology department for radiography in the common position of neutral, full extension, and full flexion position while standing. The White and Panjabi's method was used to measure the linear and angular displacements. Moreover, pain intensity was assessed using the visual analogue scale, and functional disability was investigated using a modified Oswestry Disability Questionnaire. Results: The parameter of the linear displacement at the L3-L4 level was significantly different between the two groups (P=0.02). The mean duration of low back pain was longer in the LEIS, compared to the LFIS group (P=0.01). Conclusion: In patients with LEIS, compensatory responses occur that cause less linear displacement at the L3-L4 level, compared to the patients with LFIS. Therefore, it is important to design appropriate exercises to better control the linear displacement at the L3-L4 level during the full range of motion in patients with LFIS.