2.3. Outcome measurement
Oswestry disability, Pain
LORDOSIS
In this study, the LLA was the primary outcome, and the lateral view was obtained through X-ray imaging (Accury-625R, Dk, Medical system, Seoul, Korea) that included the lumbar spine and pelvis, with the participant in a standing position. To visualize spine alignment, the participant was asked to raise both arms over their head during imaging. After imaging, the LLA was measured according to the Cobb angle measurement method using Picture Archiving and Communication System (PACS, Viewrex, HechEhim, Guro, Korea) by radiologists not involved in the study. The program measured the lordosis angle through the upper endplate of the first lumbar vertebra and lower endplate of the fifth lumbar vertebra using the Cobb angle measuring tool.The Medx extension machine (Medx 96, Ocala, FL) was used to measure the isometric spine extensor strength. The lumbar extensor strength was evaluated at 0°, 12°, 24°, 36°, 48°, 60°, and 72° in the range of spinal flexion. Before the start of the test, the measurement equipment and test method were fully explained to the participant, and a pelvic restraint was applied and fixed using pelvic and head restraints to limit the movement of the lumbar spine. During the measurement, verbal feedback was given to allow the participant to exert maximum muscle strength, and approximately 10 seconds of rest was given between each angle measurement. Each angle was measured twice, and the average value was used.Pain was assessed using a visual analog scale score range of 0 to 10 points, and lumbar function was assessed using the Oswestry disability index,