Contents lists available at ScienceDirect Manual Therapy journal homepage: www.elsevier.com/locate/math Technical and measurement report Test-retest reliability of sit-to-stand and stand-to-sit analysis in people with and without chronic non-specific low back pain Mohammad Reza Pourahmadi a , Ismail Ebrahimi Takamjani a,* , Shapour Jaberzadeh b , Javad Sarrafzadeh a , Mohammad Ali Sanjari c , Rasool Bagheri a , Elham Jannati a a Department of Physiotherapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran b School of Primary Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University Peninsula Campus, Melbourne, Australia c Department of Rehabilitation Basic Sciences, School of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran ARTICLE INFO Keywords: Functional activity Reproducibility of results Biomechanical phenomena Low back pain ABSTRACT Background: Sit-to-stand (STD) and stand-to-sit (SIT) analysis can provide information on functional in- dependence in daily activities in patients with low back pain (LBP). However, in order for measurements to be clinically useful, data on psychometric properties should be available. Objectives: The main purpose was to investigate intra-rater reliability of STD and SIT tasks in participants with and without chronic non-specific LBP (CNLBP). The second purpose was to detect any differences in lumbar spine and hips sagittal plane kinematics and coordination between asymptomatic individuals and CNLBP pa- tients during STD and SIT. Design: Cross-sectional study. Method: Twenty-three CNLBP patients and 23 demographically-matched controls were recruited. Ten markers were placed on specific anatomical landmarks. Participants were asked to perform STD and SIT at a preferred speed. Peak flexion angles, mean angular velocities, lumbar to hip movement ratios, and relative phase angles were measured. The procedure was repeated after 2 h and 6–8 days. Differences between two groups were analyzed using independent t-test. Intraclass correlation coefficient (ICC 3,k), standard error of measurement (SEM), and limits of agreement (LOAs) were also estimated. Results: The ICC values showed moderate to excellent intra-rater reliability, with relatively low SEM values (≤10.17°). The 95% LOAs demonstrated that there were no differences between the measured parameters. Furthermore, CNLBP patients had limited sagittal plane angles, smaller angular velocities, and lumbar-hip dis- coordination compared to asymptomatic participants. Conclusions: The results indicated moderate to excellent test-retest reliability of STD and SIT analysis. Moreover, CNLBP patients had altered kinematics during STD and its reverse. 1. Introduction In clinical settings, various methods have been introduced for the measurement of spine kinematics, ranging from simple tapes to com- puter application devices (e.g., motion analysis systems). Motion ana- lysis systems are noninvasive, allow to repeat the examination more times within a short period of time, and provide detailed quantitative and 3–dimensional (3D) data (Cimolin et al., 2013). Lumbar spine ki- nematics obtained using the motion analysis systems may be of value in generating functional diagnoses, assessing the mechanisms of therapies, and establishing specific rehabilitation programmes in low back pain (LBP) patients. Patients with LBP often report difficulties during daily activities, such as sit-to-stand (STD) (Andersson et al., 2010) and stand-to-sit (SIT) (Shum et al., 2005). STD consists of transferring the center of mass from a low position centered within a base of support to a high position over a shallow base of support (Tung et al., 2010). In addition, the center of mass moves in the opposite direction of STD during SIT. Previous stu- dies indicated that LBP patients usually perform STD task with limited lumbar sagittal plane angles and smaller angular velocities (Shum et al., 2005; Christe et al., 2016). However, the magnitude of movements out of the sagittal plane during STD and its reverse is very small and can be neglected in both people with and without LBP (Shum et al., 2005). In order for measurements to be clinically useful, data on https://doi.org/10.1016/j.msksp.2017.11.001 Received 4 July 2017; Received in revised form 9 October 2017; Accepted 1 November 2017 * Corresponding author. Department of Physiotherapy, School of Rehabilitation Sciences, Iran University of Medical Sciences, Madadkaran All., Shahnazari St., Madar Sq., Mirdamad Blvd., P.O. Box 4391-15875, Tehran, 1545913187, Iran. E-mail address: dr_i_ebrahimi@yahoo.com (I. Ebrahimi Takamjani). Manual Therapy xxx (xxxx) xxx–xxx 2468-7812/ © 2017 Elsevier Ltd. All rights reserved. Please cite this article as: Pourahmadi, M.R., Manual Therapy (2017), http://dx.doi.org/10.1016/j.msksp.2017.11.001