Reliability of the Flexible Ruler in Measuring Lumbar Lordosis among Children

Abstract

Introduction: Postural alignment is commonly assessed, and the abnormal postures are associated with musculoskeletal disorders. There are different methods for screening spinal column anomalies. The flexible ruler provides a safe, portable, inexpensive and non-invasive way to measure the spinal curvature in clinical and larger population. Aim: To determine the intra-rater and inter-rater reliability of flexible ruler in measuring lumbar lordosis among children. Materials and Methods: In this cross-sectional study 81 school children that fulfilled the criteria were recruited with age ranging from 9 to 15 years. Youdas method in standing position was adopted. By using flexible ruler, measurement was taken and without altering the shape of the lumbar curve it was traced in a graph sheet. By using straight ruler, line L and H were drawn by following deep point method. Lumbar lordosis angle was calculated by using the formula, θ=4Arctan 2H/L. Intra-rater reliability: Four measurements were taken by evaluator 1 with a gap of one minute between first two measurements and 3 minutes rest then other two measurements were taken with a gap of one minute between each. The average of first two and the last two measurements were considered as measurements 1 and 2. Inter rater reliability: Two measurements were taken by evaluator 2 by adapting the same procedure. The averages of two measurements were considered as measurement for evaluator 2. This value was correlated with the value of measurement 1 of evaluator 1. The data was analysed using Intra Class Correlation coefficient (ICC) test. Results: The results showed high intra-rater reliability (ICC-0.991; p<0.001) for lumbar lordosis angle by flexible ruler and poor inter-rater reliability (ICC-0.241; p=0.11) for lumbar lordosis angle by flexible ruler. Conclusion: The flexible ruler has shown only intra-rater reliability and additional studies are required to prove inter-rater reliability in measuring lumbar lordosis among children.