en Physical Therapy Physical Therapy Original Research Original Research <strong>Background: </strong>To our knowledge, no study has examined the kinematics of lumbopelvic-hip complex of individuals with chronic low back pain (CLBP) who had lumbar flexion+rotation (F+R) syndrome during sit to stand (SiToSt) and stand to sit (StToSi) activities. Thus, this study aimed to examine movement patterns of the lumbopelvic-hip complex in participants with CLBP classified into F+R syndrome subgroup.<br> &nbsp;&nbsp; <strong>Methods: </strong>This was a cross sectional study. A 3-dimensional motion capture system was used to record movements of the lumbar spine and hips during SiToSt and StToSi. Participants were 20 patients with LBP classified in lumbar F+R subgroup, based on the movement impairment system model, and 20 asymptomatic individuals. The study was approved by Shahid Beheshti University of Medical Sciences (IR, SBMU.RETECH, and REC.1395.365).<br> &nbsp;&nbsp; <strong>Results:</strong> Greater and significant lumbar flexion, with SiToSt, and lumbar extension, with StToSi, were observed in the patients. In addition, the patients exhibited a greater magnitude of lumbar rotation during SiToSt. No significant difference was observed between the 2 groups in hip motions.<br> &nbsp;&nbsp; <strong>Conclusion:</strong> The patients with lumbar F+R syndrome tend to move their lumbopelvic region to a greater extent in sagittal and horizontal planes during SiToSt and StToSi compared with participants without low back pain.<br> &nbsp; Low Back Pain, Lumbopelvic, Hip, Kinematics, Rotation 1196 1204 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-4832-2&slc_lang=en&sid=1 Meissam Sadeghisani sadeghi.m@iran.ir 200319475328460091386 200319475328460091386 No Department of Physiotherapy, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran Farideh Dehghan Manshadi sadeghi.m@sbmu.ac.ir 200319475328460091387 200319475328460091387 Yes Department of Physiotherapy, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran Khosro Khademi Kalantari 200319475328460091388 200319475328460091388 No Department of Physiotherapy, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Taghi Karimi 200319475328460091389 200319475328460091389 No School of Rehabilitation Sciences, Shiraz University of Medical sciences, Shiraz, Iran Hadi Azimi 200319475328460091390 200319475328460091390 No Department of English Language Teaching, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Afshin Aghazadeh 200319475328460091391 200319475328460091391 No Department of Rehabilitation, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran