Demographic and clinical information of the participants will be recorded using a standardized form. The cognitive status of the patient will be evaluated according to the answers to the questions asked to the patient during the questioning of demographic data and reading and signing the consent form. The participants will be asked to complete a series of questionnaires to assess pain intensity and characteristics, pain-related functional disability, and pain-related fear-avoidance behavior. To record the presence and severity of pain behaviors exhibited during physical performance tests, patients will be asked to complete 5 functional tests (repetitive trunk flexion, repetitive sit-to-stand, timed get-up-and-go test, reach with load, 50-step walk test) and observers will simultaneously complete the Pain Behavior Scale. Each participant will be asked to attend two testing sessions separated by one week and occurring before the start of treatment.

The Pain Behavior Scale was developed to record the presence and severity of pain behaviors exhibited during physical performance tests. Specific pain behaviors assessed are sighing, breath holding, grimacing, guarding, rubbing and antalgic gait. The Pain Behavior Scale consists of a 4-point scale ranging from "None" (no observed behavior) to "Severe" (marked pain behavior).

Two measures are obtained from the scale

1. The presence or absence of each behavior
2. Total score for the severity of general pain behaviors. The scale will be used during the implementation of physical performance tests lasting 10-15 minutes.

The Visual Analog Scale, which is used to record the intensity of pain, consists of a single 10 cm line; the left end is described as "No pain" and the right end is described as "The most severe pain experienced in life". Patients will be asked to mark the severity of their current pain on the 10 cm line. During the calculation, the marked point will be measured in cm. The higher the score, the more severe the pain.

The McGill Pain Questionnaire Short Form consists of three parts. In the first part, patients are asked to describe their pain with 15 descriptive words (11 sensory and 4 affective). In the second part, the severity of the patient's pain is evaluated. In the third part, patients are asked to mark their current pain intensity on a visual comparison scale.

The Oswestry Disability Index consists of 10 questions questioning the severity of pain, self-care, lifting-carrying, walking, sitting, standing, sleeping, the degree of change in pain, travel and social life and the questions are scored between 0-5. The total score is calculated as a percentage and the higher the total score, the higher the level of functional disability.