The aim of the study is to evaluate the kinematics of all spine segments in 3 planes and compare them with asymptomatic controls using wearable technology while performing functional tasks that patients with chronic low back pain often describe as painful in their daily lives.

Low back pain is an important global health problem, with 84% of the population having at least one episode of low back pain in their lifetime and 23% developing a chronic form. It has been shown in many studies that the quality of life of individuals with low back pain is seriously reduced due to problems such as depression, anxiety, attention problems, sleep disorders, and social isolation. Low back pain has serious negative effects on national economies all over the world due to incapacity and increased medical expenses. According to the International Classification System of Health, individuals with low back pain often evaluated activities such as maintaining body position, changing basic body position, lifting objects, and walking as painful in their daily lives. Studies show that patients exhibit maladaptive spinal movement strategies that include increased trunk muscle activity and decreased trunk mobility to prevent further pain or injury during these activities. It was concluded that there was no difference in lordosis angles in people with low back pain compared to healthy controls, but there was a decrease in the lumbar range of motion in all directions of motion and they moved more slowly. It is seen that most of the studies focus only on the lumbar spine while evaluating functional activities, while other segments of the spine are ignored. The limited number of studies examining other segments concluded that the angle changes did not occur only in the lumbar spine and emphasized the importance of examining other segments together. For example, in a study conducted in individuals with low back pain and healthy individuals, it was found that during the task of step-up with three different step heights, patients exhibited more extension and less flexion in the upper thoracic joints in the sagittal plane, and it was recommended to examine the head movements in future studies. The same study also noted smaller lower thoracic and upper lumbar range of motion in patients in the frontal plane. According to these results, it can be said that examining functional activities in only one plane is insufficient due to the multifaceted nature of movement in individuals with low back pain. Defining spinal angles in different planes, examining different functional activities, and evaluating the spine as a whole are necessary to understand and effectively rehabilitate the changing spinal kinematics in low back pain. With the developing technology, many kinematic analysis methods have emerged to analyze the movement of body segments. Among these, Inertial Measurement Sensors have become effective tools for objective and quantitative evaluation due to their low cost, accuracy and portability. According to this information, in this study, it aim to evaluate the kinematics of all spine segments in 3 planes and compare them with asymptomatic controls while performing the tasks that patients with chronic low back pain often describe as painful in their daily lives, using these sensors that provide valid and reliable results for the kinematic analysis of functional activities. At the end of the study, it is expected that the motion patterns of the cervical, upper-lower thoracic, and upper-lower lumbar segments in 3 planes may differ kinematically in individuals with low back pain compared to healthy individuals, and the movement of the lumbar region in 3 planes may be affected by cervical and/or thoracic region movement. These results will guide the understanding of multifactorial low back pain and will enable the determination and implementation of appropriate preventive and therapeutic strategies.

Inclusion Criteria:

For the low back pain group:

• Individuals aged 18-55 with non-specific chronic low back pain
• Individuals who have been experiencing pain for more than 3 months
• Individuals whose pain intensity is above 3 on the Visual Analog Scale

For the healthy group:

- Individuals aged 18-55 with no history of low back pain lasting more than 1 week for 6 months prior to the study

Exclusion Criteria:

• Current rheumatological or neurological diseases
• Recent or current pregnancy
• History of tumors or spine fractures
• Known spinal defects or surgery history
• Body mass index over 30 kg/m²