Reliability of the Flexible Ruler in Measuring Lumbar Lordosis among Children

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.