In a previous study, we established reliability of a method for determining the angle of lumbopelvic sagittal alignment during active knee extension in sitting (AKEiS) using a flexible ruler and image analysis software (2-point-Method). In addition to this method, a flexible ruler can also be used to measure lumbopelvic sagittal alignment without image analysis software. This study primarily aimed to investigate the minimum number of repetitions, inter-session reliability and inter-examiner reliability of two alternative methods of measurement in a secondary analysis of our previous study. A flexible ruler was used to measure lumbopelvic curvature during AKEiS when the knee reached 10° flexion from 27 individuals with clinically tight hamstring muscles and subsequently analyzed. Lumbopelvic sagittal alignment was evaluated for the region between T12 and S2 using the maximum depth to the curvature (Max-Method) or depth to the curvature at the middle point between T12 and S2 vertebral levels (Mid-Method). It was determined that four repetitions for the Max-Method and 11 repetitions for the Mid-Method were required for the minimum number of repetitions, respectively. Inter-session reliability and inter-examiner reliability were assessed using Intraclass Correlation Coefficients and were 0.91 and 0.91 for the Max-Method and 0.90 and 0.91 for the Mid-Method, respectively. The current study suggests that the Mid-Method would not be recommended for use in the clinical setting as 11 repetitions of data sampling is required. The 2-point-Method or Max-Method may be promising but the ideal measurement method will be identified when the validity of these methods has been established.
Gombatto, S.P., Collins, D.R., Sahrmann, S.A., Engsberg, J.R. and Van Dillen, L.R. (2007) Patterns of Lumbar Region Movement during Trunk Lateral Bending in 2 Subgroups of People with Low Back Pain. Physical Therapy, 87, 441-454.
Kim, M., Yoo, W. and Choi, B. (2013) Differences between Two Subgroups of Low Back Pain Patients in Lumbopelvic Rotation and Symmetry in the Erector Spinae and Hamstring Muscles during Trunk Flexion when Standing. Journal of Electromyography & Kinesiology, 23, 387-393.
Harris-Hayes, M. and Van Dillen, L.R. (2009) The Inter-Tester Reliability of Physical Therapists Classifying Low Back Pain Problems Based on the Movement System Impairment Classification System. Journal of the American Academy of Physical Medicine and Rehabilitation, 1, 117-126.
Yasuda, M., Nishimoto, K., Hori, M., Noguchi, T. and Takasaki, H. (2017) The Effect of Active Knee Extension in Sitting on Lumbopelvic Curvature in Individuals with Clinically Tight Hamstring Muscles: A Cross-Sectional Reliability Study. Open Journal of Therapy and Rehabilitation, 5, 139-147.
Rajabi, R., Seidi, F. and Mohamadi, F. (2008) Which Method Is Accurate When Using the Flexible Ruler to Measure the Lumbar Curvature Angle? Deep Pint or Mid Point of Arch? World Applied Sciences Journal, 4, 849-852.
Swait, G., Rushton, A.B., Miall, R.C. and Newell, D. (2007) Evaluation of Cervical Proprioceptive Function: Optimizing Protocols and Comparison between Tests in Normal Subjects. Spine, 32, E692-E701.
Takasaki, H., Treleaven, J., Johnston, V. and Jull, G. (2012) Minimum Repetitions for Stable Measures of Visual Dependency Using the Dot Version of the Computer-Based Rod-Frame Test. Manual Therapy, 17, 466-469.