 The purpose of this study was to measure the inter-rater and inter-rater reliability of active lumbar extension and flexion movements using dual inclinometer with two different landmarking techniques. Two examiners and two separate observers took repeated measurements from 40 participants, including both male and female patients with mild or symptomatic lower back pain, as well as healthy control subjects. Three sets of three alternating active lumbar extension and flexion movements were performed for an initial warm-up. Prior to each trial, the examiners used two different landmarking techniques to identify the start and end points of the movement. The results showed that the two landmarking techniques produced a high to very high inter-rater reliability, inter-class correlation coefficient 0.73 to 0.91. This suggests that the two landmarking techniques are reliable methods for measuring active lumbar extension and flexion movements. This article was authored by Isshak Ahmed, Muhammad Ali Mohseni Banpe, Syed Amir Jilani, and others. We are article.tv, links in the description below.